NATURAL AND SYNTHETIC POLYMERS New Biotechnology · Volume 31S · July 2014

Natural and synthetic polymers

PR-01

A mathematical model for polyhydroxybutyrate pro-duction by a wild type Bacillus megaterium using rawglycerol from biodiesel industry as sole carbon source

Paalo Andrea Moreno Yanez1,∗, Débora Jung Luvizetto Faccin2,Nilo Sérgio Medeiros Cardozo2, Humberto Escalante1, MariannyY. Combariza1, Carolina Guzmán1

1 Universidad Industrial de Santander, Colombia2 Federal University of Rio Grande do Sul, Brazil

Polyhydroxybutyrate (PHB) is a biodegradable, biocompat-ible and thermoplastic biopolymer, synthesized naturally ascytoplasmic inclusions by various genera of Gram-positive andGram-negative bacteria. PHB shares similar properties withpolypropylene, and could potentially replace it, but its industrialproduction is limited by its high cost and low productivity. Wehave previously reported [1] optimized growth conditions for awild type Bacillus megaterium with the ability to produce PHB fromraw glycerol byproduct of a Colombian biodiesel industry. Aimingfor a better understanding of the PHB biosynthetic process withthe referred carbon source and wild type Bacillus megaterium, inthe present work we present a mathematical model that allows usto describe the kinetics of microbial growth, substrate consump-tion, product formation and also to simulate different cultivationstrategies. In this model, microbial growth and product formationwere described by the Monod and the Luedeking–Piret equations,respectively. Model implementation and parameter estimationwere carried out in the EMSO process simulator. Key model param-eters were estimated from experimental data obtained in batchcultivation using a submerged bioreactor. Experimentally, underoptimized bioreactor conditions, a maximum PHB concentrationof 0.96 g/L was reached at 12 h. The model provided excellentfitting of the experimental data previously obtained, providingcorrelation coefficients around 0.9.

Reference

[1].Moreno P, Yanez C, Tarazona N, Cardozo NSM, Escalante H, Com-bariza MY, Guzmán C. Statistical optimization of PHB productionby a wild type Bacillus megaterium using raw glycerol as sole carbonsource. Int J Biol Macromol 2014 (submitted for publication).

http://dx.doi.org/10.1016/j.nbt.2014.05.897

PR-02

Acetobacter pasteurianus DSM 3509 produces cobalamin

Clemens Bernhardt ∗, Xuan Zhu, Bernward Bisping

Uni Hamburg, Germany

A strain of acetic acid bacteria used in food applications wasfound to have the ability to synthesize cobalamin. A prelimi-nary genetic study of the gene of uroporphyrinogen-III synthaseand a survival test indicated the ability to synthesize cobalamin.By a modified microbiological assay based on Lactobacillus del-brueckii spp. lactis DSM 20355, 4.57 ng/mL of real cobalamin and

0.75 ng/mL of analogues were detected. The product extracted andisolated in its cyanide form had the similar UV spectrum as stan-dard cyanocobalamin and as cobalamin produced by Lactobacillusreuteri DSM 20016. No cobalamin was detected in the fermenta-tion broth containing 1% acetate, and less cobalamin was obtainedwhen acetate started to be consumed.

http://dx.doi.org/10.1016/j.nbt.2014.05.898

PR-03

Ultrasonic-assisted production of active polysaccharidesfrom Crassostrea hongkongensis

Bingna Cai1,∗, Jianyu Pan2, Huili Sun3

1 No. 164, Xingangxi Rd, Haizhu District, P.O. Box 510301, China2 South China Sea Institute of Oceanology, Chinese Academy ofSciences, Guangzhou, China3 Chinese Academy of Sciences, Guangzhou, China

The beneficial effects of oyster extract against various disor-ders and diseases induced by oxidative stress have aroused greatconcern. Oyster polysaccharides, as immune nutrients, were con-ducted to provide nutrients for cell metabolism and prevent theside effects such as immunotoxicity and gastrointestinal toxic-ity caused by chemoradiotherapy. Ultrasonic-assisted enzymolysiswas studied to increase the active polysaccharide yield and purityfrom Crassostrea hongkongensis, showing that it is more efficientthan ultrasonic extraction or enzymatic hydrolysis alone. Onthe basis of Box-Behnken design and ridge analysis, the opti-mum conditions were obtained as ultrasonic treatment time of24 min, power of 876 W, temperature of 49 ◦C and material-solventratio of 1:6 (w/v). Furthermore, polysaccharide fraction (CHP),which was obtained by ultrasonic pretreatment and then alcalasehydrolysis at the conditions: 3000 U/g, 55 ◦C, pH 8.0 for 4 h, exhib-ited obvious scavenging effect on DPPH and hydroxyl radical(98.48 ± 0.55% and 99.20 ± 0.12%, respectively) and linoleic acidperoxidation inhibition effect (85.48 ± 0.65%) at concentrationof 5.0 mg/mL. Then the CHP was separated into three fractionsby graded ethanol precipitation. The 30–60% ethanol precipita-tion fraction (C30–60%) from CHP showed the highest activities,including promoting RAW 264.7 murine macrophage, tlympho-cyte and IEC-6 cells proliferation (the highest cell proliferationrate was 137.10% at 0.0391 mg/mL, 160.48% at 0.0781 mg/mLand 153.70% at 0.0195 mg/mL, respectively). The activities of CHPmight attribute to its uronic acid, sulfate composition and molec-ular weight. These results reveal the potential application of CHPin nutraceutical for cancer patients.

http://dx.doi.org/10.1016/j.nbt.2014.05.899

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