American Chemical Society Division of Cellulose and Renewable Materials 249th ACS National Meeting, Denver, CO, March 22-26, 2015

C. Frazier, Program Chair SUNDAY MORNING Cellulose in Solid State and Solution - Structure, Chemistry and Reaction Mechanisms: Anselme Payen Award Symposium in Honor of Thomas Rosenau A. Potthast, Organizer; F. Liebner, Organizer; L. Lucia, Organizer; P. Kosma, Presiding; J. Ralph, Presiding Papers 1-8 Functional Lignocellulosics and Nanotechnology T. Nypel, Organizer; M. S. Peresin, Organizer; I. Filpponen, Organizer; S. Spirk, Organizer; T. Nypel, Presiding; M. S. Peresin, Presiding Papers 9-19 Advances in Lignocellulosic Materials and Chemistry: A Tribute to W.G. Glasser G. Garnier, Organizer; T. G. Rials, Organizer; S. Kelley, Organizer; T. G. Rials, Presiding Papers 20-26 Lignin Biosynthesis, Characterization and Modifications T. Tamminen, Organizer; C. Crestini, Organizer; C. Crestini, Presiding Papers 27-34 Application of Computational Chemistry to Biomass Chemistry and Utilization T. J. Elder, Organizer; S. C. Chmely, Organizer; P. Ramakrishnan, Presiding Papers 35-42 SUNDAY AFTERNOON Cellulose in Solid State and Solution - Structure, Chemistry and Reaction Mechanisms: Anselme Payen Award Symposium in Honor of Thomas Rosenau A. Potthast, Organizer; F. Liebner, Organizer; L. Lucia, Organizer; H. Sixta, Presiding; A. Van Heiningen, Presiding Papers 43-50 Functional Lignocellulosics and Nanotechnology M. S. Peresin, Organizer; I. Filpponen, Organizer; T. Nypel, Organizer; S. Spirk, Organizer; I. Filpponen, Presiding; T. Tammelin, Presiding Papers 51-61 Advances in Lignocellulosic Materials and Chemistry: A Tribute to W.G. Glasser G. Garnier, Organizer; T. G. Rials, Organizer; S. Kelley, Organizer; G. Garnier, Presiding Papers 62-69 Lignin Biosynthesis, Characterization and Modifications T. Tamminen, Organizer; C. Crestini, Organizer; T. Tamminen, Presiding Papers 70-77 Application of Computational Chemistry to Biomass Chemistry and Utilization T. J. Elder, Organizer; S. C. Chmely, Organizer; P. Ciesielski, Presiding Papers 78-85 SUNDAY EVENING Advances in Lignocellulosic Materials and Chemistry: A Tribute to W.G. Glasser G. Garnier, Organizer; T. G. Rials, Organizer; S. Kelley, Organizer; Papers 86-115 General Posters C. E. Frazier, Organizer; Papers 87-153 MONDAY MORNING Cellulose in Solid State and Solution - Structure, Chemistry and Reaction Mechanisms: Anselme Payen Award Symposium in Honor of Thomas Rosenau A. Potthast, Organizer; F. Liebner, Organizer; L. Lucia, Organizer; M. Tenkanen, Presiding; D. O. Klemm, Presiding Papers 154-161 Functional Lignocellulosics and Nanotechnology I. Filpponen, Organizer; T. Nypel, Organizer; M. S. Peresin, Organizer; S. Spirk, Organizer; M. S. Peresin, Presiding; I. Filpponen, Presiding Papers 162-171 Advances in Lignocellulosic Materials and Chemistry: A Tribute to W.G. Glasser G. Garnier, Organizer; T. G. Rials, Organizer; S. Kelley, Organizer; S. Kelley, Presiding Papers 172-179 Lignin Biosynthesis, Characterization and Modifications T. Tamminen, Organizer; C. Crestini, Organizer; R. Gosselink, Presiding Papers 180-187 Frontiers in Glycoscience K. J. Edgar, Organizer; L. Wang, Organizer; L. C. Hsieh-Wilson, Presiding Papers 188-193 MONDAY AFTERNOON Cellulose in Solid State and Solution - Structure, Chemistry and Reaction Mechanisms: Anselme Payen Award Symposium in Honor of Thomas Rosenau F. Liebner, Organizer; A. Potthast, Organizer; L. Lucia, Organizer; D. G. Gray, Presiding; F. Liebner, Presiding Papers 194-201 Functional Lignocellulosics and Nanotechnology T. Nypel, Organizer; M. S. Peresin, Organizer; I. Filpponen, Organizer; S. Spirk, Organizer; T. Nypel, Presiding; C. A. Carrillo, Presiding Papers 202-212 Application of Computational Chemistry to Biomass Chemistry and Utilization T. J. Elder, Organizer; S. C. Chmely, Organizer; B. Knott, Presiding Papers 213-220 Lignin Biosynthesis, Characterization and Modifications T. Tamminen, Organizer; C. Crestini, Organizer; D. Da Silva Perez, Presiding Papers 221-228 Frontiers in Glycoscience K. J. Edgar, Organizer; L. Wang, Organizer; K. J. Edgar, Presiding Papers 229-235

MONDAY EVENING Sci-Mix C. E. Frazier, Organizer; Papers 87, 90, 93, 94, 95, 96, 98, 100, 103, 105, 109, 110, 111, 112, 115, 116, 119, 120, 126, 127, 130, 133, 135, 136, 145, 148, 153 TUESDAY MORNING Cellulose in Solid State and Solution - Structure, Chemistry and Reaction Mechanisms: Anselme Payen Award Symposium in Honor of Thomas Rosenau A. Potthast, Organizer; F. Liebner, Organizer; L. Lucia, Organizer; A. Isogai, Presiding; T. J. Heinze, Presiding Papers 236-243 Functional Lignocellulosics and Nanotechnology M. S. Peresin, Organizer; I. Filpponen, Organizer; T. Nypel, Organizer; S. Spirk, Organizer; M. S. Peresin, Presiding; T. Tammelin, Presiding Papers 244-254 Smart and Responsive Composites from Renewable Building Blocks L. A. Lucia, Organizer; Y. Habibi, Organizer; Q. Lin, Organizer; L. A. Lucia, Presiding Papers 255-262 Renewable Resources for Materials and Energy: Recent Research and Developments in Ibero-America M. L. Auad, Organizer; O. J. Rojas, Organizer; O. El Seoud, Organizer; D. Petri, Organizer; J. Campos-Teran, Organizer; O. J. Rojas, Presiding; O. El Seoud, Presiding Papers 263-270 Frontiers in Glycoscience K. J. Edgar, Organizer; L. Wang, Organizer; J. H. Prestegard, Presiding Papers 271-276 TUESDAY AFTERNOON Cellulose in Solid State and Solution - Structure, Chemistry and Reaction Mechanisms: Anselme Payen Award Symposium in Honor of Thomas Rosenau F. Liebner, Organizer; A. Potthast, Organizer; L. Lucia, Organizer; A. Potthast, Presiding; K. J. Edgar, Presiding Papers 277-283 Frontiers in Glycoscience K. J. Edgar, Organizer; L. Wang, Organizer; L. Wang, Presiding Papers 284-290 WEDNESDAY MORNING Cellulose in Solid State and Solution - Structure, Chemistry and Reaction Mechanisms: Anselme Payen Award Symposium in Honor of Thomas Rosenau A. Potthast, Organizer; F. Liebner, Organizer; L. Lucia, Organizer; L. Lucia, Presiding; T. Roeder, Presiding Papers 291-299 Functional Lignocellulosics and Nanotechnology S. Spirk, Organizer; I. Filpponen, Organizer; T. Nypel, Organizer; M. S. Peresin, Organizer; S. Spirk, Presiding; I. Filpponen, Presiding Papers 300-310 Smart and Responsive Composites from Renewable Building Blocks L. A. Lucia, Organizer; Y. Habibi, Organizer; Q. Lin, Organizer; Y. Habibi, Presiding Papers 311-318 Renewable Resources for Materials and Energy: Recent Research and Developments in Ibero-America M. L. Auad, Organizer; O. J. Rojas, Organizer; O. El Seoud, Organizer; D. Petri, Organizer; J. Campos-Teran, Organizer; M. L. Auad, Presiding; R. Christoph, Presiding; J. Vega-Baudrit, Presiding Papers 319-327 Cellulose Dissolution: New Solvents and Mechanisms N. Abidi, Organizer; E. L. Quitevis, Organizer; N. Abidi, Presiding; E. L. Quitevis, Presiding Papers 328-335 WEDNESDAY AFTERNOON ACS Award for Affordable Green Chemistry: Symposium in Honor of John Frye, Todd Werpy, and Alan Zacher L. A. Lucia, Organizer; C. E. Frazier, Organizer; L. A. Lucia, Presiding; C. E. Frazier, Presiding Papers 336-344 Functional Lignocellulosics and Nanotechnology I. Filpponen, Organizer; T. Nypel, Organizer; M. S. Peresin, Organizer; S. Spirk, Organizer; T. Nypel, Presiding; M. S. Peresin, Presiding Papers 345-351 Smart and Responsive Composites from Renewable Building Blocks L. A. Lucia, Organizer; Y. Habibi, Organizer; Q. Lin, Organizer; L. A. Lucia, Presiding Papers 352-357 Renewable Resources for Materials and Energy: Recent Research and Developments in Ibero-America M. L. Auad, Organizer; O. J. Rojas, Organizer; O. El Seoud, Organizer; D. Petri, Organizer; J. Campos-Teran, Organizer; D. Petri, Presiding; S. Madrigal, Presiding Papers 358-365 Cellulose Dissolution: New Solvents and Mechanisms E. L. Quitevis, Organizer; N. Abidi, Organizer; E. L. Quitevis, Presiding; N. Abidi, Presiding Papers 366-373 THURSDAY MORNING Conservation Science of Cellulosic Materials - Recent Developments U. Henniges, Organizer; A. Potthast, Organizer; U. Henniges, Presiding Papers 374-381 Research on Renewable Materials: US and EU Perspectives P. E. Fardim, Organizer; P. R. Navard, Organizer; P. E. Fardim, Presiding Papers 382-387 Renewable Resources for Materials and Energy: Recent Research and Developments in Ibero-America M. L. Auad, Organizer; O. J. Rojas, Organizer; O. El Seoud, Organizer; D. Petri, Organizer; J. Campos-Teran, Organizer; J. Campos-Teran, Presiding; E. Torres, Presiding Papers 388-396

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Cellulose Dissolution: New Solvents and Mechanisms N. Abidi, Organizer; E. L. Quitevis, Organizer; N. Abidi, Presiding; E. L. Quitevis, Presiding Papers 397-403 THURSDAY AFTERNOON Conservation Science of Cellulosic Materials - Recent Developments U. Henniges, Organizer; A. Potthast, Organizer; A. Potthast, Presiding Papers 404-409 Research on Renewable Materials: US and EU Perspectives P. R. Navard, Organizer; P. E. Fardim, Organizer; P. R. Navard, Presiding Papers 410-416

CELL 1

Thomas Rosenau, playful explorer of the mysteries of cellulose

Alfred D. French, Al.French@ars.usda.gov. Southern Regional Research Center, U.S. Department of Agriculture, Metairie, Louisiana, United States

Those who have been fortunate to spend significant time with Rosi and his family will soon realize that they are all amazing individuals. Even before that sinks in, you may wonder whether Antje and Rosis lively young son Sebastian is the more staid, or dare I say mature of the two males. But Rosis playful character pays off in his science. Despite lack of commercial prospects, some of their work is carried out just to see if knowledge can be increased by synthesis of a new molecule. Other work investigated a crystal found serendipitously in an NMR tube. The lecture will touch on some of the findings from crystal structures of derivatives of glucose, cellobiose and a dimer of a ketoglucoside that add significantly to the knowledge of cellulose and its chemistry.

CELL 2

Imperfections in higher plant cellulose: Crystal stacking faults and structure of crystal-crystal interfaces

Carlos Driemeier, carlos.driemeier@bioetanol.org.br. CTBE, CNPEM, Campinas, So Paulo, Brazil

We report recent advances in understanding how structure of higher plant cellulose deviates from the I and I crystal structures, which represent models of perfect cellulose crystals. In the first part of this work, we consider a type of crystallographic defect known as stacking fault [1]. This type of defect is defined by I-like molecular layers existing within I crystals. We present diffraction patterns calculated from crystals with stacking faults and show that such patterns compare favorably with experimental data. The proposed stacking faults bring a novel interpretation for I-I coexistence in higher plant cellulose. In the second part of the work, we investigate the nature of cellulose crystal-crystal interfaces, which are inherent to formation of cellulose crystal aggregates. A geometric model of these interfaces is proposed with basis on results from X-ray diffraction and moisture sorption analyses performed across wide spectrum of celluloses isolated from higher plants [2]. Furthermore, a novel analytical technique - infrared spectroscopy associated with dynamics of deuterium exchange - has been developed to selectively probe such interface regions [3]. First results from this novel technique are presented, bringing valuable information to understand cellulose supramolecular structure in crystal-crystal interface regions. [1] Driemeier, C.; Francisco, L. H. Cellulose 2014, 21, 31613169. [2] Driemeier, C.; Bragatto, J. J. Phys. Chem. B 2013, 117, 415421. [3] Driemeier et al. (in preparation).

CELL 3

Fabrication and characterization of cellulose nanoanemone

Tetsuo Kondo, tekondo@agr.kyushu-u.ac.jp. Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, Fukuoka, Japan

The aqueous counter collision (ACC) method, which is supposed as a nano-pulverizing method using only a pair of water jets, also reveals the inherent nature of living things on the individual hierarchical levels including nano-scales. When the microbial cellulose pellicle secreted by Gluconacetobacter xylinus was subjected to the ACC method, it was found to deliver single nanofibers with subfibrillation as an aqueous dispersion.More recently, an anaerobic culture using dissolved oxygen for the bacterium provided a different type of nanofiber to engage a pellicle. Namely, the secreted cellulose nanofiber was thinner and richer in I-alpha crystalline phases than that secreted in the normal culture. The engaged pellicle had a less dense network structure than the normal one. These morphological features indicated that the generated pellicle under the anaerobic condition was meta-stable to physical forces.In this study, the ACC process was, therefore, applied to the pellicle cultured under the anaerobic condition to deliver a different type of separate cellulose nanofibers. As the result, the single nanofibers obtained were found uniquely fibrillated only from the reducing end with lower collision energy. The entire structure of the separate cellulose nanofiber resembled sea anemone, and thus we have termed as cellulose nano-anemone.

CELL 4

Cellulose nanocrystals: New preparation routes, and the relationship to the structure of native cellulose

Eero Kontturi1,2, eero.kontturi@tkk.fi. (1) Department of Forest Products Technology, Aalto University, Aalto, Finland (2) Department of Chemical Engineering, Imperial College London, London, United Kingdom

Cellulose nanocrystals (CNCs) are conventionally prepared by controlled sulphuric acid hydrolysis that is harsh enough to cleave the disordered regions in the cellulose microfibril but still mild enough to leave the crystallites intact. Recently, our group has explored two alternative preparation routes to CNCs: TEMPO-mediated oxidation of microcrystalline cellulose and HCl vapour treatment of cotton fibres (filter paper). The first method, TEMPO-mediated oxidation of microcrystalline cellulose, resulted in nanocrystals of higher charge density than in traditional CNCs, but the yield of CNCs was low (~4%). Most of the microcrystals were converted to large, porous particles with high charge density and as shown by cryo TEM high degree of alignment between the cellulose crystallites that they were composed of. The second route, hydrolysing cotton fibres with HCl vapour, led to uncharged CNCs, yet their yield was extremely high (>98%). The yield and the behaviour of both substrates under CNC preparation conditions are discussed from the point of view of the structure of native cellulose. In addition, swelling of a CNC network on an ultrathin film under increased humidity is explored and discussed.

CELL 5

Structural characteristics influencing the reactivity of isolated cellulose I

Tomas Larsson1,2, tomas.larsson@innventia.com. (1) Innventia AB, Stockholm, Sweden (2) KTH, Wallenberg Wood Science Center, Stockholm, Sweden

Isolated cellulose I, can be considered to be a semi-crystalline solid. Being one of the most abundant organic compounds on the planet, its use in the production of commodities has attracted attention for a long time. The ease by which cellulose rich materials can be converted into chemicals or materials with desirable properties, inevitably depend on the reactivity of cellulose. The complex arrangements of the b-(1,4)-D-glucan polymers in isolated cellulose creates a supramolecular structure in the 1 nm 100 nm range, capable of directly influencing the reactivity and possibly also the chemistry of cellulose I. In this paper examples will be presented illustrating the influence of the supramolecular structure of isolated cellulose I on its solubility, chemical reactivity and enzymatic reactivity. Examples will also be given illustrating the importance of well characterized samples for the purpose of correctly interpreting results from enzymatic reactivity measurements. A crystalline lattice of cellulose I type exists within fibrils. In a sense fibrils are the smallest building blocks of the supramolecular structure found in isolated cellulose I, with fibril aggregates as building blocks at the next level. Fibrils with widths of 3 nm to 5 nm are typically found in cellulose isolated from wood. Due to their relatively high density and stability, fibrils presents the phase boundaries responsible for the maximally achievable specific surface area (SSA) of cellulose I. Co-axial aggregation of fibrils and the presence of a fibril aggregate network may limit the effective SSA. The specific surface area and fibre wall average pore size are shown to be factors influencing the reactivity of cellulose I isolated in the form of fibres. The b-(1,4)-D-glucan polymers present at fibril surfaces are the initial targets for any chemical modification. Results indicate that the b-(1,4)-D-glucan polymers present at fibril surfaces in isolated cellulose I exist in a structurally and dynamically distinct state. Surface polymers are significantly different from those present in the fibril interior. Based on these findings connections between the properties of the surface polymers and their reactivity, and connections to the measurable degree of crystallinity of cellulose I will be discussed.

CELL 6

Identifying different hydroxyl populations in cellulose by 2H MAS NMR

Erik Lindh1,2, erlindh@kth.se, Camilla Terenzi1,2, Istvn Fur2, Lennart Salmn1,3. (1) Wallenberg Wood Science Center, KTH Royal Institute of Technology, Stockholm, Sweden (2) Division of Applied Physical Chemistry, KTH Royal Institute of Technology, Stockholm, Sweden (3) Innventia AB, Stockholm, Sweden

Cellulose fibers have properties that make them a promising renewable resource for creating strong composite materials. A weakness of cellulose-based materials is, though, that their advantageous properties are seriously affected when coming in contact to water. One contributing reason for this effect is the relatively high density of hydroxyl groups on the fiber surface through which water can modulate fiber-fiber

interactions. If the state of the surface hydroxyl groups were characterized better, it should be possible to develop a better understanding of how to minimize the effect of water in cellulose composites.Traditionally, deuterium (2H) NMR studies of cellulose assessed molecular mobility by detecting the motionally averaged 2H spectrum. Here, we demonstrate using 2H magic-angle-spinning (MAS) NMR to access different populations of hydroxyl groups at the surface of 2H-exchanged cellulose fibers. The cellulose fibers are initially equilibrated in 2H2O atmosphere of controlled humidity and then dried in a highly controlled manner so as to avoid contact with ambient H2O. This process replaces the hydrogens of the accessible hydroxyl groups by 2H. Different surface hydroxyl groups with distinct molecular mobility are then observed by their response in inversion recovery experiments with 2H MAS NMR detection.

CELL 7

High-resolution solution-State NMR of wood and pulp in ionic liquid electrolytes

Ashley J. Holding, Valtteri Mkel, Kari J. Helminen, Ilkka Kilpelainen, Alistair W. King, alistair.king@helsinki.fi. Department of Chemistry, University of Helsinki, Helsinki, Finland

Ionic liquids are known to be highly effective solvents for cellulose. They are mainly being investigated for cellulose dissolution/regeneration and chemical modification applications. However, they also offer potential, as direct-dissolution media, for the analysis of wood and pulps, which are rich in cellulose. In this abstract we present our results on the 1 & 2D NMR analysis of cellulose dissolved in tetraalkylphosphonium acetate: DMSO-d6 electrolytes. The resolution is such that common polysaccharide resonances, including reducing end anomers, have been identified in several pulp samples. These can be identified in the 1H spectra even for the highest molecular weight dissolving pulps, offering new opportunities for analyses. Wood treated under various conditions has also been analysed, giving more insight into the factors which affect wood solubility in direct dissolution solvents. Solubility was also found to be dependent on the size of the cation in the electrolyte. At larger cation size solutions were found to be isotropic until their saturation points. At lower cation sizes liquid-crystalline phases were found to form at relatively low pulp concentrations. In this regard, changes in the NMR spectra, as a function of cellulose concentration and temperature will also be discussed.

CELL 8

NMR analysis of periodate-oxidation products of 5-N-acetylneuraminic acid methyl glycosides and 2,8-polysialic acid (PSA)

Paul Kosma, paul.kosma@boku.ac.at. Chemistry, University of Natural Resources Life Sciences, Vienna, Austria

Periodate oxidation of -(28)-linked polysialic acid PSA has frequently been used to generate an aldehyde group at C7 of the distal end unit of the polysaccharide chain to be used in subsequent conjugation to protein carriers [1,2]. In-depth analysis of reaction products ranging from Neu5Ac mono- to tetramers, 4 kDa and 20 kDa polymers and their respective periodate-oxidized products by high-field NMR spectroscopy allowed for a detailed analysis of non-degenerate signals at

both reducing and non-reducing termini, respectively. Moreover, the presence of a free 7-aldehyde group could be excluded. Instead, oxidation of both anomeric Me glycosides gave the 7-hydrated aldehyde products, whereas oxidation of the oligomeric and polymeric substrates led to interresidue hemiacetal formation extending from C7 of the terminal end group to O-9 of the neighboring Neu5Ac residue [3]. Acknowledgment The oxidized 4 kDa polysialic acid material was kindly provided by Serum Institute of India Ltd.

Refs: [1] M. Mhlenhoff et al., Curr. Opinion Struct. Biol. 1998 (8) 558. [2] L.M. Krug et al., Clin. Cancer Res. 2004 (10) 916. [3] G.J. Ray, N. Ravenscroft, J. Siekmann, Z. Zhang, P. Sanders, U. Shaligram, C. M. Szabo, P. Kosma, Bioconj. Chem. 2014 (25) 665.

CELL 9

Pickering foams from cellulose nanofibrils

Lars Wagberg1, wagberg@kth.se, Nicholas Tchang Cervin2. (1) Fibre Polymer Technology and Wallenberg Wood Science Centre, KTH Royal Institute of Technology, Stockholm, Sweden (2) Wallenberg Wood Science Center, Stockholm, Sweden

During the last decade there has been a huge interest in new materials from nanocellulosic either in the form of cellulose nano crystals (CNC) or cellulose nanofibrils (CNF)1. The interest is partly based on our urgent need for renewable raw materials in todays society and partly on new efficient production methods both for CNC and CNF. However, both the CNC and the CNF are prepared at very low solids concentration and their handling and conversion to final materials poses significant challenges. We have shown that it is possible to prepare strong, low density CNF foams using solids concentration between 1 and 10 g/l. To do this we have used a pickering foam technique where surface modified CNFs are used to stabilize air bubbles which become so stable that they can be dried with a maintained structure. By using fluorescently labelled CNF and high speed photography it was shown that the fibrils do concentrate at the air/water interface and that they are able to stabilize two air bubbles forced together. On a more fundamental level our results also show that the accumulation of the CNFs at the air/water interface both increases the complex viscoelastic modulus of the interfaces and decreases the interfacial tension. It is also demonstrated that the aspect ratio of the particles is important since CNF is much more efficient in increasing the foam stability compared with CNC with a similar chemical composition and the efficient gel-forming ability of the CNF at the interface is suggested to be a major explanation to the excellent foam stability during dewatering and drying of the foam. Klemm, D., Kramer, F., Moritz, S., Lindstrm, T., Ankerfors, M., Gray, D. and Dorris, A. (2011) Nanocelluloses: A new Family of Nature Based Materials. Angewandte Chemie (International Ed. in English), 200, 54385466.

CELL 10

Inhibition of alphavirus infection with tyrosine sulfate mimetic cellulose nanocrystals

Justin O. Zoppe1, justin.zoppe@epfl.ch, Ville Ruottinen2, Janne Ruotsalainen2, Seppo Rnkk2, Leena-Sisko Johansson3, Ari Hinkkanen2, Kristiina Jrvinen2, Jukka Seppl3. (1) Institute of Materials, Polymers Laboratory, EPFL, Lausanne, Switzerland (2) University of Eastern Finland, Kuopio, Finland (3) Aalto University, Espoo, Finland

The spread of diseases caused by arthropod-borne viruses calls for the development of novel inhibitors that can be used for topical treatment and prevention in endemic areas. Tyrosine sulfate-mediated interactions, and often sulfated polysaccharides, play a crucial role in viral infections and are a potential target for biomimetic nanostructures. We believe cellulose nanocrystals (CNCs) offer a natural nanotechnology-based alternative to other classes of polyanionic inhibitors. By the nature of sulfuric acid hydrolysis, CNCs carry a multivalent display of anionic sulfate groups on their surfaces. We developed multiple approaches for introducing multivalent displays of tyrosine sulfate mimetic ligands on the surface of CNCs. Subsequently, we used CNCs to inhibit fluorescent marker expressing Semliki Forest virus vector (VA7-EGFP) infection in primate cells in vitro. Furthermore, when tyrosine sulfate mimetic CNCs were applied to VA7-EGFP, improved viral inhibition was observed. Additionally, functionalized CNCs did not cause observable toxicity to multiple cell lines. We propose that conjugation of target-specific functionalities to CNC surfaces provides a means to control their antiviral activity and could be potentially employed against a broad range of viruses, including HIV and Herpes simplexes.

CELL 11

Modification of nanocellulose with natural molecules: A green perspective for cellulose based materials with active properties

Araceli Garcia1,2, araceli.garcia@lgp2.grenoble-inp.fr, Alessandro Gandini1, Naceur Belgacem1, Julien Bras1. (1) Laboratoire de Gnie des Procds Papetiers (LGP2),

Grenoble INP-Pagora, Grenoble, France (2) Department of Chemical and Environmental Engineering, University of the Basque Country UPV/EHU, Donostia-San Sebastin, Spain

Because its availability and renewability, the use of cellulose fibers and crystals for the development of renewable and bio-nano-based composites is gaining great interest in last decades. Moreover, the replacement of synthetic additives by naturally obtained active compounds (antioxidants, antifungals, toxins and radical scavengers) results a very important issue from social, health and economic points of view. In the present work, cellulose nanowhiskers and nanofibers were grafted with different compounds containing functional groups naturally available (aromatics, furanics) and for which bioactive activity has already been reported. In this regard, the bioactive groups grafted nanocelluloses were used together with different renewable matrices for the in the formulation of bio-nano-inspired composites and the development of smart and active materials.

CELL 12

Size exclusion nanocellulose based paper filter for virus removal

Albert Mihranyan, albert.mihranyan@angstrom.uu.se. Nanotechnology and Functional Materials, Dep of Engineering Sciences, Uppsala University, Uppsala, Sweden

Viral contamination of biotechnological products is a serious challenge for production of therapeutic proteins and vaccines. Because of the small size, virus removal is a non-trivial task, and, therefore, inexpensive and robust virus removal filters are highly demanded. Synthetic polymer based virus removal filters are expensive because they are produced through tedious multistep phase-inversion processing involving hazardous solvents and rigorous pore annealing processing. Cermaic based virus removal filters are heavy, hard to regenerate (or to dispose), and thus impractical. Cellulose is one of the most common materials to produce various types of filters because it is inexpensive, disposable, inert, non-toxic, mechanically strong, hydrophyllic, stable in a wide range of pH, and withstanding sterilization e.g. by autoclaving. Normal paper filter, used for chemistry, has too large pores to remove viruses. A nanocellulose based paper filter is designed which is capable of removing virus particles with the efficiency matching that of the best industrial virus filters[1]. The reported paper filter, which is manufactured according to the traditional paper making processes, consists of 100% high purity cellulose nanofibers directly derived from nature. The main mechanism of virus removal is size exclusion rather than interception of viruses via electrostatic interactions, which are sensitive to pH and salt concentrations. The filtration properties of the membrane have been verified using controlled size polystyrene latex beads tagged with fluorophore groups (Figure 1) and swine influenza virus (SIV) particles.

[1]. Metreveli, G., Wgberg, L., Emmoth, E., Belak, S., Strmme, M., Mihranyan, A. (2014). Size-exclusion nanocellulose filter paper for virus removal, Advanced Healthcare Materials, 3(10): 1546-1550

Figure 1. Polystyrene latex beads (100 nm) retained on a nanocellulose based paper filter as studied by scanning electron microscopy.

CELL 13

Antibacterial surface modification of nanocellulosic materials

Jonatan Henschen, hens@kth.se, Josefin Illergrd, Per Larsson, Monica Ek, Lars Wgberg. Department of Fibre and Polymer Technology, KTH Royal Institute of Technology, Stockholm, Sweden

Nanocellulose is a family of high-performance biomaterials characterized by high stiffness, strength and biocompatibility, and is proposed as a component in many applications, ranging from barrier products to absorbency and medical products. For many of these applications it can be desirable to incorporate antibacterial properties to protect the product and/or the user. Antibacterial modification of nanocellulose is commonly done through incorporation of inorganic antimicrobial agents such as colloidal silver. The use of silver is controversial and can lead to environmental problems as the silver leaches out and is even thought to lead to antibiotic resistance. It is therefore desirable to find safer and sustainable alternatives. It has been shown that cellulosic fibers can be made antibacterial by adsorption of polyelectrolyte multilayers (PEMs) consisting of polyvinylamine and polyacrylic acid (Illergrd, J.; et al. Cellulose 2012, 19, 1731-1741). The adsorption takes place in water and is performed at room temperature using low-toxicity compounds. On the fibers, the PEMs works via a contact-active antibacterial mechanism, i.e. the bacteria are immobilized upon contact, and do not leach toxic compounds. The same technique is possible to adapt to nanocellulose and to thereby obtain a sustainable and environmentally-friendly antibacterial nanocellulose material. In the present work, materials produced from cellulose nanofibrils were modified with the above-mentioned polyelectrolytes. The two tested materials consisted of low-density aerogels with high specific areas and high water absorbance capacity as well as films with good oxygen barrier properties suitable for packaging applications. The results showed that it is possible to adsorb PEMs on both nanocellulose aerogels and films. The modified aerogels efficiently removed bacteria from solutions while maintaining its structure and ability to absorb water. The films showed lower antibacterial effect compared to both the aerogels and the previously tested cellulosic fibers and is still under evaluation. Still, the results on the aerogels demonstrate the feasibility of using the PEM technique on nanocellulose materials. By introducing an environmentally friendly

antibacterial modification on materials made from nanocellulose, we are able to further improve on the advantages of nanocellulose materials in technically demanding areas such as the food, medical and hygiene area.

CELL 14

Tuning the properties and yield of cellulose nanocrystals in the production space

Junyong Zhu, jzhu@fs.fed.us. USDA Forest Service, Madison, Wisconsin, United States

Cellulose nanocrystals (CNCs) are commonly produced using strong acid hydrolysis of cellulosic fibers. The reduction of cellulose degree of polymerization (DP), sulfation of cellulose, and production of CNC under strong acid concentrations occurred abruptly and simultaneously. As a result, process control and optimization are very difficult. For over 60 years, sulfuric acid concentration of approximately 64wt% has been used as the standard condition for producing CNCs with good dispersion properties due to the formation of sulfate groups that imparts electrostatic stability, important for aqueous processing. Low CNC yield of approximately 30-50% has been the main drawback of this standard production acid concentration despite several optimization studies were carried out in the last several decades. Furthermore, the properties of the resultant CNCs are not much affected by varying other hydrolysis conditions at standard acid concentration of 64 wt%. Here we present the first kinetic study of strong acid hydrolysis reaction of cellulosic fibers. We were able to identify a transition acid concentration of 58% below which low CNC yield is due to insufficient cellulose deploymerization, while above which low CNC yield was caused by CNC dissolution by acid. This finding provides a mechanism for controlling CNC yield by simply controlling acid concentration. Laboratory bench scale experiments verified that CNC yield of over 70% can be achieved when a bleach hardwood pulp was used. We also found that acid concentration can be used to produce desired CNC properties, such as CNC morphology, crystal length, crystallinity, and surface charge. The importance of this study is that the production of CNCs can now be tailored to a specific application, for example, CNCs with large aspect ratio (or long crystal length) may be most desirable for polymer reinforcement in composite, while low aspect ratio CNCs with uniform crystal length and high crystallinity may be more suitable for smart windows or LED displays.

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Properties of nanocellulose from wood pulp and bacterial cellulose obtained by different methods

Laura Vikele1,2, vikelelaura@inbox.lv, Inese Sable1, Linda Rozenberga1,2, Rita Treimane2,1, Arnis Treimanis1,2, Pavels Semjonovs2. (1) Latvian State Institute of Wood Chemistry, Riga, Latvia (2) Institute of Microbiology and Biotechnology, Riga, Latvia

Nanostructured cellulose (NSC) serves as a promising candidate for composite products. The aim of the study was to develop nanostructurated cellulose (NSC) preparation methods from bleached birch pulp and bacterial cellulose (BC). BC has ribbon-shaped fibrils, high crystallinity degree, higher water holding capacity and higher degree of polymerization. BC creates interest as a new raw material for obtaining

nanoparticles. At the LS Institute of Wod Chemistry thermocatalytic method is developed and later improved by chemical oxidation pre-treatment. Also method of regeneration of NSC from ionic liquids (IL) and traditional acid hydrolysis were applied. Thermocatalytic method: materials are impregnated with a weak acid (HCl) solution and thermally treated, then dispersed in water medium in a ball mill. To improve thermocatalytic method TEMPO (employing 2,2,6,6-tetramethyl-piperidinyl-1-oxyl radical) catalysed oxidation pre-treatmen was used. When using another oxidizer from traditional ones like periodate, perchlorate or persulphate for chemical pre-treatment destructed pulp sample is mixed with oxidizer that has been dissolved in HCl and heated. Cellulose sample is washed with deionized water and afterwards treated by mixing and heating with NaOH and following washing. To obtain nanoparticle gel the grinding in a ball mill is required. Many problems for thermocatalytic method are solved by using oxidizer the energy consumption is decreased by 80% during the grinding, obtained homogeneous nanoparticles with certain shape. Crystallinity degree increase from 60% to 80-90%. Ionic liquids (IL) are new eco-friendly solventsfor cellulose dissolution. ILs have abbility to modificate cellulose, both - physically and chemically, even to nanoparticles in case of specific IL and sonification. Regeneration method was performed with 1-butyl-methylimidazolium hydrogen sulfate (Bmim HSO4) IL. Acid hydrolysis was carried out in the traditional way with 64% H2SO4 , followed by dialysis . Particles obtained were analyzed with Malvern ZetaNanosizer, atomic force microscopy (AFM), electron scanning microscopy (ESM) and x-ray diffraction (XRD).

Table 1. Cristallinity degree of cellulose samples by XRD

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Nanocrystalline cellulose from agricultural waste for optical devices

Lisa Maria Steiner1, lms89@cam.ac.uk, Ahu G. Dumanli1,2, David Reid1, Melinda Duer1, Silvia Vignolini1. (1) Department of Chemistry, University of Cambridge, Cambridge, United Kingdom (2) Soft Matter Physics, Adolphe Merkle Institute, Fribourg, Switzerland

Grape pomace is a cellulose-rich agricultural waste product in the wine industry. In natural form cellulose is constituted of amorphous and crystalline parts assembled into fibrillar form. It is possible to extract the cellulose nanocrystals (CNCs) from pomace through a multistep chemical purification and hydrolysis process. In this work we demonstrate the extraction of CNCs from the skin of white grapes [1]. XRD, NMR and FT-

IR were used to characterise the starting material, the extraction process and the extracted cellulose micro-fibrils. Then, these cellulose micro-fibrils were hydrolysed into cellulose nanocrystals via acid hydrolysis, and AFM and SEM were used to understand their morphological parameters such as dimensions and particle size distribution. At a critical concentration, water based suspensions of CNCs are shown to assemble into a chiral nematic phase that can be maintained in the dry state, giving rise to strong iridescent colourations [2,3]. These chiral nematic solid films have very interesting optical properties such as only reflecting left handed circularly polarised light. As the second stage of this study we tested the self-assembly behaviour of the grape skin based CNCs by evaporating from an aqueous suspension in a controlled environment. Optical characterisation of the obtained films was performed with optical microscopy and optical goniometry [4].

[1] Lu P., Hsieh Y.; Carbohyd. Polym.; 87; 2546-2553; (2012) [2] A. G. Dumanli, G. Kamita, J. Landman, H. van der Kooij, B. J. Glover, J. J. Baumberg, U. Steiner, S. Vignolini; Adv. Opt. Mat. 2; 646-650; (2014) [3] A. G. Dumanli, H. van der Kooij, G. Kamita, E. Reisner, J. J. Baumberg, U. Steiner, S. Vignolini; ACS Appl. Mater. Interfaces 6 (15); 1230212306; (2014) [4] Vignolini S., Moyroud E., Glover B.J., Steiner U.; J R Soc Interface; 10; (2013)

AFM image of cellulose nanocrystals obtained from grape skin as shown in the inset.

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Characterisation and reinforcing properties of cellulose nanocrystals esterified in water

Benjamin Dhuiege, bdhuiege@enscbp.fr, Gilles Sbe. Laboratoire de Chimie des Polymres Organiques, University of Bordeaux, Pessac, France

Cellulose NanoCrystals (CNC) can significantly improve the mechanical performances of polymers at low loading levels offering opportunities for new high value-added nanocomposite materials. But to achieve an improvement of these properties, good interfacial interactions must be obtained and the CNC must be homogeneously dispersed in the polymeric matrix, which is not trivial. Because of their high surface area and their hydrophilic nature, the CNC cannot be easily dispersed in low polarity mediums rendering it difficult to efficiently reinforce most of the classical polymer matrices. The dispersability of the CNC in such media can however be improved by surface functionalization: chemical functions can be grafted at the CNC surface to decrease the interfacial energy and increase their interaction with the matrix (physical and/or chemical interactions). In this context, we envisaged tailoring the CNC surface by two original esterification methods performed in water. The first one is based on the transesterification of vinyl esters and the second one on carboxylic acid reactions activated by water-soluble carbodiimide (EDCI). The CNC surface after reaction was characterized by Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The supramolecular structure of the nanoparticles was examined by X-ray diffraction (XRD) and atomic force microscopy (AFM). The reinforcing properties of esterified CNC were subsequently investigated using naturel rubber as a model matrix. The impact of the esterification treatment on the properties of the nanocomposites will be particularly discussed through various microscopic, thermal and mechanical characterizations (SEM, TEM, DMA).

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Control of the surface properties of cellulose nanocystals by transesterification of vinyl esters

Jrmie Brand, jeremie.brand@gmail.com, Gilles Sbe. Laboratoire de Chimie des Polymres Organiques, University of Bordeaux, Bordeaux, Aquitaine, France

In the current context of sustainability, there is a growing interest in developing novel functional materials based on sustainable bioresources. In particular, cellulose nanocrystals (CNC) are nanometer-sized particles, which can be easily recovered from cellulosic substrates (wood pulp, microcrystalline cellulose) by sulfuric acid treatment. Because of their high specific strength, modulus and aspect ratio, CNC can significantly improve the mechanical performances of polymers, at low loading levels. They can also serve as stabilizing agents in Pickering emulsions, as matrix for the preparation of aerogels or foams, or as templating agents. But to realize the full potential of these applications, the CNC surface must be tuned by appropriate functions to control its dispersive, interfacial and self-assembling properties. In this context, a novel and straightforward method for the surface esterification of CNC by transesterification of vinyl esters is proposed. The reaction of vinyl esters with the CNC hydroxyl groups was examined in different solvents, with potassium carbonate as catalyst. Reactions were performed under microwave activation and monitored by Fourier transform infrared spectroscopy (FT-IR) and Nuclear Magnetic Resonance (NMR) spectroscopy. The supramolecular structure of the CNC before and after modification was characterized by X-ray diffraction (XRD) and atomic force microscopy (AFM). The thermal stability was evaluated by thermogravimetric analysis (TGA). The dispersibility of the acetylated nanoparticles was examined in various solvents of different polarities, using dynamic light scattering (DLS). The impact of solvent and reaction time on the efficiency of the

reaction and nanoparticles integrity will be particularly discussed.

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One step polymer grafting of poly(methyl methacrylate) from cellulose nanocrystals for composite applications

Stephanie Kedzior, kedziosa@mcmaster.ca, Lexa Graham, Emily D. Cranston. Chemical Engineering, McMaster University, Hamilton, Ontario, Canada

Cellulose nanocrystals (CNCs) are desirable in composite materials due to their low cost, bioavailability, light weight and renewability. CNCs form stable colloidal suspensions in water, however their hydrophilic nature often limits their applications, since dispersing CNCs in hydrophobic polymer matrices and organic solvents poses many challenges. In this work, we have used a grafting-from method to graft short chain poly(methyl methacrylate) (PMMA) polymers from the surface of cellulose nanocrystals using ceric ammonium nitrate as the initiator in a one step, water-based polymerization. PMMA-grafted-CNCs were characterized using NanoSight nanoparticle tracking analysis, atomic force microscopy, zeta potential, X-ray photoelectron spectroscopy, contact angle, and nuclear magnetic resonance. PMMA-grafted-CNCs were incorporated into bulk PMMA composites using melt mixing and wet ball milling methods and the mechanical, rheological and morphological properties of CNC composites were assessed.

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Mechanisms of biogenic formaldehyde generation in wood

Charles E. Frazier, cfrazier@vt.edu, Guigui Wan, Mohammad Tasooji, Heather Wise. Sustainable Biomaterials, Virginia Tech , Blacksburg, Virginia, United States

We seek to understand the formation of natural biogenic formaldehyde in solid wood, and how biogenic formaldehyde impacts compliance with emissions regulations for non-structural wood composites. Upon heat treatment, P. virgininia wood generates substantial quantities of formaldehyde with no detectable change in sugar composition, and with a large reduction in lignin thioacidolysis yield. This suggestion of lignins role was predicted in past studies of beta-O-4 models, and that the gama methylol group is activated for formaldehyde generation. Our attempts to test this mechanism verify some but not all predictions from the lignin literature. Furthermore it appears that extractives in P. virginiana also play a large role. Our attempts to identify mechanisms of formaldehyde generation will be described. The presentation will demonstrate that current regulations require a thorough accounting of both synthetic and biogenic formaldehyde sources.

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Amphipathic lignin derivatives for enzymatic saccharification and fermentation of lignocellulosics

Yoko Yamamoto1, kulibo.dt.kbbc.54my.kinda.song@gmail.com, Ningning Cheng1, Kiyohiko Igarashi3, Keiichi Koda2, Yasumitsu Uraki2. (1) Graduate School of Agriculture, Hokkaido University, Sapporo, Hokkaido, Japan (2) Research Faculty of Agricuture, Hokkaido

University, Sapporo, Japan (3) Department of Biomaterial Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan

An enzymatic saccharification of lignocellulosics using cellulase is considered as an environmentally benign, first process for bioethanol production. However, the enzyme cost is a main obstacle to its widespread application. Enzymatic saccharification also faces difficulty in the repeated use of cellulase. Several additives, such as non-ionic surfactant and polyethylene glycol (PEG) with the molecular mass of more than 4000 Da, have been reported to overcome the problems. We also developed amphipathic lignin derivatives as the additives, which were prepared from isolated lignins by the reaction with epoxylated PEG analogues. When the lignin derivatives were added to enzymatic saccharification media, the sugar yield was significantly increased, and the cellulase used could be recovered with remarkably high enzyme activity from the media. In this study, we investigated the effect of the amphipathic lignin derivatives on simultaneous saccharification and fermentation process (SSF) of unbleached pulp, and the mechanism to explain their contribution to enzymatic saccharification. In a fed-batch SSF, bioethanol concentration was significantly increased from 37.8 % to 49.4 % by the addition of amphipathic lignin derivatives. This possitive effect was assumed to be attributed to their high sacchrification efficiency with the cellulase activity maintained during the process. Hence, the interaction of cellulase with amphipathic lignin derivatives and PEG 4000 was examined by Biocore, an analyzer to monitor weight gain resulting from the association between biological molecules based on surface plasmon resonance. As a result, amphipathic lignin derivatives were strongly adsorbed onto cellobiohydrases (CBH) I and II that are the major components of cellulase derived from Trichoderma reesei, while they were not adsorbed on endoglucanase (EG). These different affinities are considered to be caused by the difference in the structures of CBH and EG. On the other hand, PEG 4000 was not adsorbed on any enzyme. This result suggests that the positive effect of PEG on enzymatic saccharification is not attributed to its association with cellulase. Thus, the mechanisms of our amphipathic lignin derivatives and PEGs on the improved enzymatic saccharification are quite different.

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Homogeneous tosylation of agarose as an approach towards functional bio-based materials

Martin Gericke, martin.gericke@uni-jena.de, Thomas J. Heinze. Friedrich Schiller University of Jena, Jena, Germany

With respect to the limitations of fossil-based materials, exploration and innovative use of bioresources become increasingly important. Agarose, an abundant seaweed polysaccharide (PS) that is renowned for its thermoreversible gelation, has considerable potential in this context for the preparation of functional biomaterials, e.g., hydrogels and tissue-scaffolds. It is non-ionic and provides a large density of OH-groups, i.e., agarose is well suited for polymer analogues chemical modification. Tosylated polysaccharides are key-intermediates that can be converted with a vast variety of nucleophiles to yield functional derivatives with specific features. Based on knowledge on the preparation of classical PS-derivatives, e.g., derived from cellulose or starch, tosylation of agarose was studied with respect to the effects of the reaction parameters (type of PS-solvent, time, amount of

tosylation reagent) on the molecular structure of the products. Tosyl agaroses (TOSA) with high DStosyl 1.81 were obtained in completely homogeneous reactions and characterized by FT-IR and 1D-/2D-NMR spectroscopy. Despite the structural resemblance of agarose and cellulose, TOSA showed a unique substitution pattern that could be triggered from non-preferential to regioselective tosylation by performing the reaction with or without LiCl. Finally, the nucleophilic displacement reaction of TOSA was studied using azide and ethylendiamine with the aim to yield products (i) for click-chemistry approaches, (ii) with specific surface affinity/self-assembling properties. The novel deoxy-agarose derivatives obtained partly showed thermoreversible gelation and will be used for creating functional bio-based materials.

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From sustainable chemical blocks to fuel: Synthesis of hydrocarbons from isoprene and acrolein

Zhaohui Tong, ztong@ufl.edu, Fei Wang. University of Florida, Gainesville, Florida, United States

The conversion of biomass to biofuels and value-added chemicals has attracted numerous attention in terms of less dependence on fossil fuel and increasing concerns on environmental problems. Hydrocarbon fuels such as diesel and jet fuel (C8-C21) have an advantage because of compatibility with the current infrastructure and a higher energy density suitable for truck and jet engines. Many routes have extensively studied to produce hydrocarbon fuels using furfural-based chemicals as the starting materials. Herein, we reported new approach for the synthesis of hydrocarbon fuels (C8 and C16) using abundant biomass-derived chemicals isoprene and acrolein as the starting materials. C8 hydrocarbon can be prepared directly by two-step reaction including a Diels-Alder reaction between isoprene and acrolein to form 4-methyl-cyclohex-3-enecarbaldehyde followed by a hydrodeoxygenation reaction with up to 57% total yield. The transition metal catalysts such as Pt/C, Pd/C, Fe/SiO2 and Ni/SiO2 were screened to optimize the product yield. Furthermore, a long chain C16 hydrocarbon was also synthesized by a sequence of Diels-Alder reaction, reductive coupling, and hydrodeoxygenation from isoprene and acrolein as well.

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Development of an efficient polymer analogous reaction in ionic liquids and its application to chemical modification of lignocellulose

Ryohei Kakuchi, kakuchi@se.kanazawa-u.ac.jp, Yoshiki Shibata, Makoto Yamaguchi, Kenji Takahashi. Institute of Science and Engineering, Kanazawa University, Kanazawa, Japan

As driven by a growing demand on alternative resources, chemists have initiated researches on utilization of raw biomass to produce chemicals, which targets chemical industry without employing fossil resources. Biomass, in other words the ligunocellulose, is known to be composed of three main components, namely the lignin, the hemicellulose, and the cellulose with highly sophisticated architectures. Usually, biomass utilization has been depending on the depolymerization processes of either lignin or polysaccharides. Hence, reported biomass utilization approaches were thermodynamically and economically disadvantageous. Because of the limited solubility and reactivity of lignocellulose, chemical modification of lignocellulose has been extremely difficult for long years. A pioneering work in the field of biomass utilization was reported in 2002 by Rogers and co-workers, in which they have experimentally demonstrated that ionic liquids (ILs) could dissolve cellulose under mild conditions. Triggered by this report, other bio renewable materials including lignin and even a raw biomass itself have been discovered to be dissolved in ILs under mild conditions. Along with a fruitful properties of ILs as solvent for biomass components, ILs have been recently found to catalyze organic transformation reactions in ILs with ILs as a catalyst. These findings encouraged us to target chemical modification of biomass in ILs with an organo-catalytic ability of ILs. Herein, we now develop a conceptually new biomass utilization approach, which is essentially based on a polymer analogous reactions of the polysaccharide and lignin of the biomass. We paid our attention to the common character of lignocelluloses. To be precise, the hydroxyl groups exist in any components of biomass. Therefore, the biomass modification was defined as the polymer analogous reaction of polymers featuring hydroxyl groups, namely the cellulose, the hemicellulose, and the lignin. In this presentation, we describe 1) an efficient polymer analogous reaction of cellulose in ILs with ILs as a catalyst to afford modified cellulose and 2) polymer analogous reaction of biomass in ILs to afford polysaccharide and lignin derivatives.

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Fundamental approaches to multiscale, multiphase phenomena in cellulose pyrolysis chemistry

Christoph Krumm, krumm026@umn.edu, Alex Paulsen, Paul J. Dauenhauer. Chemical Engineering & Materials Science, University of Minnesota, Twin Cities, Minneapolis, Minnesota, United States

Biomass pyrolysis is a promising thermochemical method for producing renewable fuels and chemicals from biomass. Development of a fundamental understanding of biomass pyrolysis chemistry is difficult due to the multi-scale and multi-phase nature of the process; biomass length scales span 11 orders of magnitude and pyrolysis phenomena include solid, liquid, and gas phase chemistry in addition to heat and mass transfer [1]. These complexities have a significant effect on chemical product distributions [2]. Fundamental understanding of cellulose pyrolysis chemistry in the absence of heat/mass transfer limitations will allow for detailed chemical input-output models used to scale up and optimize biomass pyrolysis reactors. In this work, we describe the design of a new high temperature reactor used to study cellulose pyrolysis chemistry. The mechanisms and pathways of the primary reactions of cellulose pyrolysis, including solid-liquid-vapor transformations, are experimentally characterized. Our findings highlight the importance of mass transfer on cellulose pyrolysis chemistry and provide insight for the rational design of full-scale pyrolysis reactors.

[1] Mettler, M. S., Vlachos, D., and Dauenhauer, P. J., Energy & Envrinmental Science, 2012, 5(7), 7797-7809 [2] Paulsen, A. D., Mettler, M. S., and Dauenhauer, P. J., Energy & Fuels, 2013, 27(4), 2126-2134 [3] Di Blasi, C., Prog. Energy Combust. Sci., 2008, 34, 4790

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Valorization of lignin to renewable fuels and chemicals through biological funneling and chemical catalysis

Derek Vardon1,2, dvardon2@illinois.edu, Mary Ann Franden2, Christopher Johnson2, Eric Karp2, Michael Guarnieri2, Jeffrey Linger2, Philip Pienkos2, Timothy J. Strathmann1, Gregg Beckham2. (1) University of Illinois at Urbana Champaign, Lakewood, Colorado, United States (2) National Renewable Energy Laboratory, Golden, Colorado, United States

Lignin is an alkyl-aromatic polymer present in plant cell walls for defense, structure, and water transport. Despite exhibiting a high-energy content, lignin is typically slated for combustion in modern biorefineries due to its inherent heterogeneity and recalcitrance; however, it is critical for the economic success of third-generation biorefineries to valorize lignin alongside polysaccharides. This talk presents an integrated strategy that employs biological conversion, separations, and catalysis to convert lignin-derived species into renewable plastics, fuels, and polymer precursors. Native and engineered strains of Pseudomonas putida were utilized to produce (1) intracellular medium chain length polyhydroxyalkanoic acids (mcl-PHAs) for direct use as renewable plastics or for subsequent catalytic conversion to hydrocarbon fuels, and (2) extracellular cis,cis-muconic acid for subsequent catalytic conversion to adipic acid, a nylon 6-6 precursor. Shake flask and fed-batch biological conversion studies were conducted with model lignin monomers, as well as with a depolymerized lignin stream derived from alkaline pretreatment of corn stover. Downstream processing strategies were examined to selectively recover target metabolites, and subsequent catalytic processing was demonstrated with a wide range of chemical catalysts. Collectively, this effort provides a path forward towards valorizing lignin to renewable fuels and chemicals through an integrated scheme of biological funneling and chemical catalysis.

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-O-4 -type quinone methides in lignin biosynthesis and in pulping

Jussi Sipila1, jussi.sipila@helsinki.fi, Anssi Haikarainen4, Paula Nousiainen2, Mikko Muuronen3. (1) University of Helsinki, Helsinki, Finland (2) Organic chemistry, University of Helsinki, Helsinki, Finland (3) Department of Chemistry, University of Helsinki, 00014 Helsingin yliopisto, Finland (4) Medicinal chemistry, Orion Corporation, Espoo, Finland

p-Quinone methides constitute one of the most important class of reactive intermediates in chemistry of plant biomass. In our laboratory we have specifically investigated the reactivity of different types of -O-4 p-quinone methides, precursors of arylglycerol-b-aryl ether structures. The results give new aspects on the role of quinone methides in lignin chemistry. While in aqueous solution at low pH (pH3) quinone methides react quatitatively with water, at pH 6 significant amounts of products formed via homolytical degradation pathway were

observed with quinone methides containing syringyl structures. It was also found that the stereochemistry in the addition of water to QMs at pH3 was closer to that found in native lignins than at pH6. These findings suggest that lignin biosynthesis may take place at lower pH than commonly suggested or the QM reaction are otherwise catalysed by Lewis acids. In the alkaline degradation of the arylglycerol -O-4 structures, on the other hand, the effect of sulphidity on the course of reactions was followed. In addition to the experiments with dimeric QMs the reactivity of a large variety of oligomeric -O-4 type lignin models (trimers, tetramers, pentamers) and DHP was followed by model cookings. The results were then compared with the structural information obtained from isolated lignins of different types of alkaline cooks (conv. Kraft, Soda-AQ, Polysulphide-AQ, Flow-trough Kraft). The results demonstrate some interesting differences in the behavior of quinone methides in kraft and soda cooks

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Molecular models of milled-wood lignin

Peter Schiffels1, peter.schiffels@ifam.fraunhofer.de, Heiko Lange2, Claudia Crestini2. (1) Fraunhofer IFAM, Bremen, Germany (2) Universit degli Studi di Roma Tor Vergata, Rome, Italy

Lignin is the second most abundant bio-polymer which accounts for approximately 30% of the organically bound carbon. Lignin exhibits a heterogeneous composition and according to present knowledge lacks a defined primary structure, its composition generally characterized by the relative abundance of H/G/S units and by the distribution of interunit bonding motifs. Various methods exist to reveal the molecular details of lignin structure and most notably, there have been significant advances in the interpretation of quantitative HSQC-data and 31P-NMR spectra including end-group titration. For Norway-Spruce Milled Wood Lignin (NS-MWL), the currently available data provide sufficient information for the construction of detailed molecular models. In this talk, we demonstrate that the experimentally determined relations between structural moieties or groups of structural moieties can be used to formulate a well-defined set of linear independent equations for the lignin structure. Standard numerical techniques are used to solve the algebraic equations for the most relevant structural motifs, which now enables us to actually construct molecular models for individual oligomeric lignin chains which in sum are representative of the whole lignin sample. Starting from chain terminations, oligomeric lignin chains are assembled as 2-D SMILES representations by randomly connecting the motifs according their respective abundance. Using present day computers, it is feasible to generate thousands of SMILES-strings in reasonable times and we show that this ensemble of 2-D molecular models not only reproduces the known experimental data, but can also be utilized to predict the effect of functionalizations such as the change in molecular weight distribution as the sample is subjected to AcBr treatment.

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Mechanical properties of bamboo nanofibers: An atomistic simulation study

Sina Youssefian2, Nima Rahbar1,2, nrahbar@wpi.edu. (1) Civil Engineering, Worcester Polytechnic Institute, Worcester, Massachusetts, United States (2) Mechanical Engineering,

Worcester Polytechninc Institute, Worcester, Massachusetts, United States

Bamboo, a fast-growing grass, has a higher strength-to-weight ratio than steel and concrete. The unique properties of bamboo come from the natural composite structure that comprises mainly of cellulose nanofibers in a matrix of intertwined hemicellulose and lignin called lignin-carbohydrate complex (LCC). Here, we have utilized atomistic simulation to investigate the mechanisms of interaction between these materials present in the nanostructure of bamboo. With this aim, we have developed a molecular model of LCC from lignin and hemicellulose structures to study the elastic moduli, glass transition temperatures and their adhesion energies to cellulose nanobril faces. Good agreements are observed between the simulation results and experimental data, indicating the validity of the models. Studying the Nanostructural proper- ties of these materials suggests that the abundance of hydrogen bonds in hemicellulose chains is responsible for the mechanical behavior of LCC. The strong van der Waals forces between lignin molecules and cellulose nanobril cause relatively large adhesion energy between LCC and cellulose nanofibrils.

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Impact of changes in the lignin synthetic pathway on cell wall architecture

Jiliang Liu2, ligerliu@gmail.com, Joanne C. Cusumano3, Jeong Im Kim3, Clint chapple3, Lee Makowski1. (1) Northeastern University, Boston, Massachusetts, United States (2) electrical and computer engineering, northeastern university, Malden, Massachusetts, United States (3) Department of Biochemistry, purdue univeristy, West Lafayette, Indiana, United States

We used scanning x-ray microdiffraction to the study of the impact of mutations in the lignin biosynthetic pathway on the architecture of the plant cell wall. Microdiffraction from the plant cell wall was separated into oriented and disoriented components using custom software. The oriented component exhibits significant cellulosic reflections indicating that the oriented material in the plant cell wall is mainly composed of cellulose fibrils. Although the disoriented component shows considerable cellulosic scattering, distinct non-cellulosic diffraction observed is suggestive of amorphous formation of non-cellulosic material. Lignin induced mutants introduce a modulation of the observed intensity in the small angle region. This modulation may rise from interference due to enhanced ordering of cellulose fibrils. Inter-fibril distance was estimated on the basis of a two-cylinder model. The interference calculation indicates that the distance between cellulose fibrils in plant cell wall is increased in plants with enhanced lignin content. The (2 0 0) cellulosic reflections exhibited double orientation in most tissues. The angle between the split reflections is referred to as the microfibril angle. The increase in microfibril angle from xylem to pith indicates that variation in lignin content affects the ordering of cellulose fibril in a tissue specific fashion. Although the rate of variation in microfibril angle among lignin mutants and wild type were different the maximum and minimum in microfibril angle was essentially unchanged. These studies indicate that lignin content is tightly correlated with the degree of order and orientation of cellulose

fibrils in plant cell walls and provide evidence as to the nature of the lignin-cellulose interactions.

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Diastereoselective fungal ligninolysis

Daniel J. Yelle2, dyelle@fs.fed.us, Alexander N. Kapich3,4, Carl Houtman2, Fachuang Lu1, Vitaliy Tymokhin1, Raymond C. Fort5, John Ralph1, Kenneth Hammel2,3. (1) Department of Biochemistry, University of Wisconsin, Wisconsin Energy Institute, Madison, Wisconsin, United States (2) Forest Products Laboratory, U.S. Forest Service, Madison, Wisconsin, United States (3) Department of Bacteriology, University of Wisconsin, Madison, Wisconsin, United States (4) Institute of Microbiology, National Academy of Sciences of Belarus, Minsk, Belarus (5) Department of Chemistry, University of Maine, Orono, Maine, United States

The white rot basidiomycete Ceriporiopsis subvermispora delignifies wood selectively and has potential biotechnological applications. Its ability to remove lignin before the substrate porosity has increased enough to admit enzymes suggests that small diffusible oxidants contribute to delignification. A key question is whether these unidentified oxidants attack lignin via single electron transfer (SET), in which case they are expected to cleave its propyl sidechains between C and C and to oxidize the threo-diastereomer of its predominating -O-4-linked structures more extensively than the corresponding erythro-diastereomer. We used two-dimensional solution-state NMR techniques to look for changes in partially biodegraded lignin extracted from spruce wood after white rot by C. subvermispora. The results showed that (a) benzoic acid residues indicative of CC cleavage were the major identifiable truncated structures in the lignin after decay, and (b) depletion of -O-4-linked units was markedly diastereoselective with a threo preference. The less selective delignifier Phanerochaete chrysosporium also exhibited this diastereoselectivity on spruce, and a P. chrysosporium lignin peroxidase operating in conjunction with the P. chrysosporium metabolite veratryl alcohol did likewise when cleaving synthetic lignin in vitro. However, C. subvermispora was significantly more diastereoselective than P. chrysosporium or lignin peroxidase/veratryl alcohol. Our results show that the ligninolytic oxidants of C. subvermispora are collectively more diastereoselective than currently known fungal ligninolytic oxidants, and suggest that SET oxidation is one of the chemical mechanisms involved.

Chemical reactions occurring during: (a) Cleavage of lignin structure A via fungal SET oxidation, followed by autooxidation of the resulting lignin benzaldehydes; (b) Formation of structure A in the lignifying plant cell wall via free radical coupling and nucleophilic

addition of water, showing routes for production of the erythro- and threo-diastereomers.

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Exquisite sensitivity of Acridine Orange to lignocellulosic oxidation and mechanistic investigation

Peter Kitin1,2, Joe Worple2, Jon Houtman3, Kenneth E. Hammel1,2, Christopher G. Hunt1, cghunt@fs.fed.us, Carl J. Houtman1. (1) US Forest Service, Forest Products Laboratory, Madison, Wisconsin, United States (2) Bacteriology, University of WIsconsin - Madison, Madison, Wisconsin, United States (3) Microbiology, University of Iowa, Iowa City, Iowa, United States

Surface oxidation precedes depolymerization of lignocellulosic biopolymers during fungal decay. We have observed that the metachromic fluorescent dye acridine orange (AO) indicates the oxidation state of wood surfaces. Fresh wood adsorbs AO in a manner that results in green emission. In the first three panels of the figure, thin sections exposed to a white-rot fungus, Phanerochaete chrysosporium exhibit fluorescence that begins as green and progresses to red by seven days. Acid-chlorite treatment and UV exposure also result in red emission (panels 4,5). AO has found wide application as a microscopy stain, due to its metachromic behavior. The association of poly nucleic acids with AO appears to have two mechanisms. With double-stranded DNA and RNA, AO is electronically isolated and emits green. In contrast, charged interactions dominate interactions with single strands, which favors stacking of AO molecules. Stacking results in a combined electronic state between two AO molecules giving a red fluorescent emission and fluorescent energy transfer (FRET) quenching of any isolated AO molecules within the Frster distance. We wish to understand the chemical modifications that are responsible for the shift in AO-wood interaction. Apparently, unmodified wood adsorbs AO as isolated molecules. Microcrystalline cellulose, Sigmacell, and milled wood enzyme lignin fluoresce green. Carboxy methylated agarose beads, however, fluoresce red. These observations lead to the hypothesis that carboxylic acid sites are important for associations leading to red fluorescence, which may be produced during oxidation. This is consistent with isothermal titration calorimetry data, which indicate strong binding sites and elimination of red fluorescence by competitive adsorption by calcium. Fluorescence lifetime measurements also indicate FRET between the green and red fluorescent species on wood.

Acknoledgement: Supported by DE-SC0006929 from the U.S. DOE, BER

Fluorescence of AO-stained white spruce wood after: (A) 0 days, (B) 3 days, (C) 7 days colonization by P. chyrsoporium, and after (D) acid chlorite oxidation. (E) Cross section of a pine specimen after UV

exposure, showing oxidation at the surface (left and top) but not in the interior of the wood.

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Lipoxygenase: A new oxidative enzyme for lignin biorefinery

Claudia Crestini, crestini@uniroma2.it, Heiko Lange, Paola Giann, Elisavet Bartzoka. Department of Chemical Sciences and Technologies, University of Rome 'Tor Vergata', Rome, Italy

The biotechnological conversion of lignocellulosic biomass is widely used within the development and refinement of biorefinery processes. Rather than functionalising lignin, however, enzymatic treatments are used during the initial pre-treatment of biomass for easing separation of components, or for funnelling purposes during the production of different fuel classes out of initial degradation products. Numerous studies exist that describe the use lignocellulosic enzymes of laccases, peroxidases, cellulases in biorefinery processes (e.g., Van Dyk et al. 2012). We report here for the first time the use of lipoxygenase for the valorisation of lignin. Based on detailed mechanistic insight (Zoia et al. 2011), we used commercially available lipoxygenase (EC 1.13.11.x) for structurally modifying lignins. Control of reaction conditions allow the generation of different structural features within oligomeric lignin chains, and to covalently link functional moieties naturally not present in lignin to the lignins via non-hydrolysable covalent bonds. VanDyk, J.S., Pletschke, B.I. (2012). A review of lignocellulose bioconversion using enzymatic hydrolysis and synergistic cooperation between enzymesFactors affecting enzymes, conversion and synergy. Biotechnology Advances, 30(6), 1458-1480. Zoia, L., Perazzini, R., Crestini, C., Argyropoulos, D.S. (2011). Understanding the radical mechanism of lipoxygenases using 31P NMR spin trapping. Bioorganic & Medicinal Chemistry, 19(9), 3022-3028.

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Quantitation of S/G ratio in woods using 1064 nm FT-Raman spectroscopy

Umesh P. Agarwal, uagarwal@fs.fed.us, Sally Ralph. Forest Products Lab, Madison, Wisconsin, United States

A simple and accurate method based on 370 cm-1 Raman band intensity was developed for quantification of syringyl-to-guaiacyl ratio in woods. One of the major advantages of the method is that woods (and probably other lignocelluloses) can be directly analyzed and no prior isolation of lignin is required. Therefore, the S/G ratio is representative of the whole cell wall lignin and not just the isolated part or the portion of lignin that gets cleaved during certain S/G chemical analyses. Besides, additional problems associated with the traditional approaches are avoided. The Raman analysis is quick, is free of use of harmful chemicals, carried out nondestructively, and is insensitive to the wet or dry state of the sample. The only limitation is that a wood sample be not significantly fluorescent. Although in the case of the latter, in some cases, methods exist to rectify the situation. To test the accuracy of the Raman method, the obtained S/G ratios were calibrated against the

values generated by the DFRC and 2D-13C NMR methods. The former being an S/G method that takes into account only the cleaved -O-4 lignin units whereas NMR reports S/G ratio on the whole cell wall lignin. Reliability of the Raman approach was further supported by the quantitative analysis of several syringyl lignin models.

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Synthesizing cellulose

Brandon C. Knott1, brandon.knott@nrel.gov, Michael F. Crowley1, Michael Himmel1, Jochen Zimmer2, Gregg Beckham1. (1) National Renewable Energy Laboratory, Golden, Colorado, United States (2) University of Virginia, Charlottesville, Virginia, United States

Cellulose is the most abundant biomaterial on Earth, yet the mechanism of its synthesis has only begun to be revealed. Understanding cellulose biosynthesis is a significant problem with direct relevance to both glycopolymer sciences and the design of new energy feedstocks with reduced recalcitrance. After decades of research by groups worldwide, an unprecedented discovery was reported in 2013 when the first crystal structure of a bacterial cellulose synthase (Bcs) protein complex was solved.1 Intriguingly, this multi-domain, membrane-bound Bcs was captured with an intact cellulose chain of 18 glucose units threaded through the binding tunnel in an activated state. From this crystal structure, it is clear that Bcs adds one glucose molecule at a time to the growing cellulose chain from a UDP-glucose donor substrate. After each glucose residue is added to the growing chain, the entire chain must move forward one glucose unit before further elongation. Further details of this processive cycle are unknown. We investigate various scenarios of both the chemical reaction and translocation with advanced molecular simulation methods. The former of these utilizes transition path sampling of hybrid QM/MM (quantum mechanical/molecular mechanical) simulations. These simulations enable the computation of free energy barriers, reveal detailed mechanistic information regarding the glycosyl transfer chemical reaction and cellulose translocation, and aid in elucidating the nature and order of the discrete steps of the synthase processive cycle. This work constitutes the first dynamical look at the method by which the majority of Earths organic carbon is produced.

1J.L. Morgan, J. Strumillo, J. Zimmer, Nature 493, 181 (2013).

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QM/MM and MD study on catalytic mechanism of bacterial CESA

Hui Yang2, hyang2016@gmail.com, Jung-Goo Lee1, Jochen Zimmer3, Yaroslava G. Yingling1, James D. Kubicki2. (1) Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina, United States (2) Geosciences, The Pennsylvania State University, State College, Pennsylvania, United States (3) Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, United States

Cellulose is a linear polymer of glucose molecules and represents the most abundant renewable hydrocarbon source in the world. Cellulose synthesis in plants is mediated by

cellulose synthase (CESA), a membrane-bound glycosyltranferase family 2 enzyme, polymerizing glucose molecules via glycosidic bonds between the C1 and C4 carbons. CESA utilizes activated glucose, UDP--D-Glucose (the donor), as substrate and inverts the configuration of the newly added glucosyl residue from to . Cellulose is also produced by some bacteria, especially Gram-negative species, where its biosynthesis is often concomitant with the formation of biofilms. Bacterial biofilms are of particular concern to human health due to their increased tolerance to antibiotics and disinfectant chemicals. Due to difficulties in expressing and manipulating catalytically active CESA enzymes, the molecular mechanism of plant cellulose biosynthesis is still elusive. The catalytic mechanism of bacterial cellulose synthase was investigated by using a hybrid quantum mechanics and molecular mechanics (QM/MM) approach. The Michaelis complex model was built based on the X-ray crystal structure of the cellulose synthase subunits BcsA and BcsB containing a uridine diphosphate molecule and a translocating glucan. A SN-2-type transition structure corresponding to the nucleophilic attack of the non-reducing end O4 on the anomeric carbon C1, the breaking of the glycosidic bond C1-O1, and the transfer of proton from the non-reducing end O4 to the general base Asp343 has been identified via the QM/MM simulation. The activation barrier found for this SN-2-type transition state is 68 kJ/mol. The rate constant of polymerization is estimated to be ~8.0 s-1 via transition state theory. Another Michaelis complex model was built based on the X-ray crystal structure relaxed with 200ns MD simulations at 300 K. The catalytic mechanism obtained from MD relaxed structure has been compared to the one obtained from X-ray crystal structure.

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Molecular dynamics simulation study of the AxCeSD octamer compelxed with cellulose chains

Toshifumi Yui1, tyui@cc.miyazaki-u.ac.jp, Takuya Uto1,5, Yuki Ikeda3, Kenji Tajima2, Min Yao4. (1) Faculty of Engineering, University of Miyazaki, Miyazaki, Japan (2) Graduate School of Engineering, Hokkaido University, Sapporo, Japan (3) Graduate School of Engineering University of Miyazaki, Japan, Miyazaki, Japan (4) Faculty of Advanced Life Science, Hokkaido University, Sapporo, Japan (5) Research Fellow of Japan Society for the Promotion of Science, Miyazaki, Japan

The cellulose syntheses subunit D octamer in Acetobacter xylinum (AxCeSD) is one of the four (A to D) subunits composing the cellulose synthesizing terminal complex. AxCeSD, coupled with AxCeSC, is suggested to play roles in glucan chain extrusion and crystallization. The 3D structure of the AxCeSD exhibits an exquisite cylinder shape of octamer assembly.1 It also was suggested that a cellulose chain passed through each of the dimer-dimer interfaces as an inner pathways. The present study reports the computer docking and molecular dynamics (MD) studies of the AxCeSD-cellulose complex model to evaluate interactions between surfaces of the pathways and cellulose chains. Cellulose chains with DP = 24 were manually docked in the pathways to form the complex model (Fig. 1). The 50 ns NTP MD calculation (300 K and 1 bar) was carried out for the complex model in solution state. The average binding energy values based on the final 20 ns trajectories were evaluated for each pathway and then decomposed by a residue. Inside the pathways, water molecules diffused around the equatorial sides of the cellulose chains where polar functional groups were arrayed and the hydrophobic pyranose faces tended to interact with amino acid residues.

Hydroxylmethyl groups were allowed to rotate frequently in the pathways. The largest negative value, ranging about -7 to -4 kcal/mol pre residue, was found in the interior glucose residues. Hu et al reported that cellulose production was greatly depressed in the mutant cell with the AxCeSD gene of N-terminus truncation up to Lys6.1 The present MD calculations indicated that interactions with the cellulose chains were detected from Ile3 and the following amino acid residues. 1. Hu S-Q, et al. Proc. Natl. Acad. Sci. USA 2010, 107, 17957-17961.

Fig. 1 The structure of the AxCeSD and cellulose complex model.

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Molecular basis for cellulose twist

Michael F. Crowley, michael.crowley@nrel.gov, Lintao Bu, Michael Himmel. National Renewable Energy Lab, Lakewood, Colorado, United States

The observation of twisted microfibrils in cellulose I both in imaging and in molecular simulations has been reported and studied for years. Other crystalline forms of cellulose do not show evidence of twisting at the microfibril scale. This article reports a computational modeling study of cellulose I twist showing its strong dependence on fibril diameter and no dependence on fibril length or DP. We report the major cause of the twist in the model empirically and analytically as the hydrogen bonding that spans the glycosidic linkage. The lack of twist in other forms of cellulose is strengthened by the need for the TG orientation of primary alcohols, which only cellulose I has, to form the twist-causing hydrogen bonds.

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DFT calculations on the thermodynamics of PCW component interactions

James D. Kubicki1, jdk7@psu.edu, Virgil Gibilterra1, Thomas Weiss1, Heath Watts2, Loukas Petridis3, Paul Langan4, Linghao Zhong5. (1) Geosciences, The Pennsylvania State University, State College, Pennsylvania, United States (2) Space Telescope Science Institute, University Park, Pennsylvania, United States (3) Center for Molecular Biophysics, Oak Ridge National LAboratory, Oak Ridge, Tennessee, United States (4) MS 6475, Oak Ridge National Lab, Oak Ridge, Tennessee, United States (5) Chemistry, Penn State Mont Alto, Mont Alto, Pennsylvania, United States

A major goal in plant science is to construct an accurate, detailed model of the plant cell wall (PCW - both primary and secondary). Models have been proposed and improved over the past few decades as information from biological experiments, microscopy, mechanical tests, and spectroscopy have added to our understanding of plant cell wall component interactions. Although the assembly of plant cell walls is not expected to be an equilibrium process, we hypothesize that plant cell wall architecture takes advantage of thermodynamically favorable interactions in order to optimize the strength of the cell wall. Consequently, in this work, we estimate the interaction energies of cellulose, hemicellulose, lignin and pectin with one another using density functional theory (DFT) calculations. Tetramer models are used with and with explicit solvation via H2O molecules in order to examine the effect water may have on PCW interactions. We also compare the DFT energies and structures to those obtained with the classical force fields CHARMM and COMPASSII. Discussion of the various modeling approaches, comparison to experimental observations and the implications for the chemical strength of PCW component interactions will be included.

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Can crystal structure conformations help validate conformational analyses of isolated molecules?

Alfred D. French, Al.French@ars.usda.gov. Southern Regional Research Center, U.S. Department of Agriculture, Metairie, Louisiana, United States

Some time ago, we tested a proposal that molecules in crystals could be considered to be randomly deformed, compared to their minimum-energy shapes in isolation. (French et al., J Mol Graph Model 18 (2000) 95107; Carbohydr Res 326 (2000) 305322.) Recent work for a review article (French, DOI 10.1007/978-3-319-03751-6_33-1) expanded the range of analyses to include geometries for furanose rings, as well as new disaccharide linkage geometries. Given an energy hypersurface for a given molecule such as a Ramachandran f,y map for a disaccharide, the corresponding energies for the geometries in various related crystal structures can be obtained. For example, sufficiently related molecules might include methyl lactoside when f and y of cellobiose are being studied. According to the hypothesis of Brgi and Dunitz (Acta Crystallogr Sect B 44 (1988) 445448) the distribution of these energies should resemble a Boltzmann distribution, and a temperature of the distribution can be derived by fitting an exponential equation to the curve. Several apparently successful fittings suggest that a temperature of about 500K

is appropriate to mimic the geometric variations observed in crystals. It is also necessary to consider the overall distribution to learn whether all of the low-energy areas are occupied by observed conformations. Typically, some concession to the condensed phase is needed in the modeling study.

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Hydration control of the mechanical and dynamical properties of cellulose

Loukas Petridis1, petridisl@ornl.gov, Hugh M. ONeill2, Mariah Johnsen7, Bingxin Fan3, Eugene Mamontov6, Janna K. Maranas4, Roland Schulz1, Paul Langan5, Jeremy C. Smith1. (1) Center for Molecular Biophysics, Oak Ridge National LAboratory, Oak Ridge, Tennessee, United States (2) Biology and Soft Matter Division, Oak Ridge Natl Lab, Oak Ridge, Tennessee, United States (3) The Pennsylvania State University, University Park, Pennsylvania, United States (4) Penn State University, University Park, Pennsylvania, United States (5) MS 6475, Oak Ridge National Lab, Oak Ridge, Tennessee, United States (6) Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States (7) Ripon College, Ripon, Wisconsin, United States

The mechanical and dynamical properties of cellulose are essential for its function in plant cell walls and advanced biomaterials. Cellulose is almost always found in a hydrated state, and it is therefore important to understand how hydration influences its dynamics and mechanics. Here, the nanosecond-timescale dynamics of cellulose is characterized using dynamic neutron scattering experiments and molecular dynamics (MD) simulation. The experiments reveal that hydrated samples exhibit a higher average mean-square displacement above ~240 K. The MD simulation reveals that the fluctuations of the surface hydroxymethyl atoms determine the experimental temperature and hydration dependence. The increase in the conformational disorder of the surface hydroxymethyl groups with temperature follows the cellulose persistence length, suggesting a coupling between structural and mechanical properties of the biopolymer. In the MD simulation 20% hydrated cellulose is more rigid than the dry form, due to more closely-packed cellulose chains and water molecules bridging cellulose monomers with hydrogen bonds. This finding may have implications for the use of cellulose in composite materials as well as understanding the origin of strength and rigidity of secondary plant cell walls. The detailed characterization obtained here provides a clear link between structural, dynamical and mechanical properties of this important biomolecule.

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Modeling graphene-cellulose-water interactions