an emerging field for metabolic engineering of lactic acid...
TRANSCRIPT
![Page 1: An emerging field for metabolic engineering of Lactic Acid ...uni-lab.net/Materials/students/BSc-strains... · NUTRACEUTICALS: An emerging field for metabolic engineering of Lactic](https://reader034.vdocuments.us/reader034/viewer/2022042119/5e97c784740f1608736f8070/html5/thumbnails/1.jpg)
NUTRACEUTICALS:An emerging field for metabolic
engineering of Lactic Acid BacteriaMALVIKA MALIK1, RAVINDER NAGPAL1, MONICA PUNIYA2, ARTI
BHARDWAJ3, SHALINI JAIN4 and HARIOM YADAV4*
1Dairy Microbiology, 2Dairy Cattle Nutrition, 4Animal Biochemistry,National Dairy Research Institute, Karnal 132001,
Haryana, Meerut Institute of Engineering and Technology, Meerut-250002, U.P., India.
*Email: [email protected]
![Page 2: An emerging field for metabolic engineering of Lactic Acid ...uni-lab.net/Materials/students/BSc-strains... · NUTRACEUTICALS: An emerging field for metabolic engineering of Lactic](https://reader034.vdocuments.us/reader034/viewer/2022042119/5e97c784740f1608736f8070/html5/thumbnails/2.jpg)
Nutraceuticals
• The term ‘Nutraceuticals’, launched by
Stephen De-Felici in the 1980s
• A food or part of a food that may provide
medicinal or health benefits, including the
prevention and treatment of disease.
![Page 3: An emerging field for metabolic engineering of Lactic Acid ...uni-lab.net/Materials/students/BSc-strains... · NUTRACEUTICALS: An emerging field for metabolic engineering of Lactic](https://reader034.vdocuments.us/reader034/viewer/2022042119/5e97c784740f1608736f8070/html5/thumbnails/3.jpg)
Metabolic Engineering
Metabolic engineering is the practice ofoptimizing genetic and regulatoryprocesses within cells to increase the cells'production of a certain substance
Controlled over expression of desiredgenes
Inactivation of undesired genes
![Page 4: An emerging field for metabolic engineering of Lactic Acid ...uni-lab.net/Materials/students/BSc-strains... · NUTRACEUTICALS: An emerging field for metabolic engineering of Lactic](https://reader034.vdocuments.us/reader034/viewer/2022042119/5e97c784740f1608736f8070/html5/thumbnails/4.jpg)
![Page 5: An emerging field for metabolic engineering of Lactic Acid ...uni-lab.net/Materials/students/BSc-strains... · NUTRACEUTICALS: An emerging field for metabolic engineering of Lactic](https://reader034.vdocuments.us/reader034/viewer/2022042119/5e97c784740f1608736f8070/html5/thumbnails/5.jpg)
Examples of metabolicengineering of LAB
• Increased production of diacetyl fromglucose and lactose
• Efficient production of L-alanine from sugar• Production of non-metabolisable sugars• Galactose and/or lactose removal from dairy
products• Oligosaccharide production• Vitamin production
![Page 6: An emerging field for metabolic engineering of Lactic Acid ...uni-lab.net/Materials/students/BSc-strains... · NUTRACEUTICALS: An emerging field for metabolic engineering of Lactic](https://reader034.vdocuments.us/reader034/viewer/2022042119/5e97c784740f1608736f8070/html5/thumbnails/6.jpg)
Lactic acid bacteria as cell-factories
• Lactic acid bacteria (LAB) are industriallyimportant microbes, used in a large variety offood fermentations
• The NICE system for controlled heterologousand homologous gene expression in Lacticacid bacteria has been employed in many ofthe metabolic engineering strategies
(Boels et al. 2001; Sybesma et al. 2002)
![Page 7: An emerging field for metabolic engineering of Lactic Acid ...uni-lab.net/Materials/students/BSc-strains... · NUTRACEUTICALS: An emerging field for metabolic engineering of Lactic](https://reader034.vdocuments.us/reader034/viewer/2022042119/5e97c784740f1608736f8070/html5/thumbnails/7.jpg)
Why Lactic acid bacteria?
• The bacterium is food grade
• Plasmid selection mechanisms are available that are foodgrade and self cloning
• No endotoxins or inclusion bodies are formed and
• Sophisticated genetic tools enable easy genetic handling
• Simple, non-aerated fermentation makes direct scale-upfrom 1-L scale to 1000-L scale possible
• Nisin controlled gene expression can be effectively used
![Page 8: An emerging field for metabolic engineering of Lactic Acid ...uni-lab.net/Materials/students/BSc-strains... · NUTRACEUTICALS: An emerging field for metabolic engineering of Lactic](https://reader034.vdocuments.us/reader034/viewer/2022042119/5e97c784740f1608736f8070/html5/thumbnails/8.jpg)
NICE
![Page 9: An emerging field for metabolic engineering of Lactic Acid ...uni-lab.net/Materials/students/BSc-strains... · NUTRACEUTICALS: An emerging field for metabolic engineering of Lactic](https://reader034.vdocuments.us/reader034/viewer/2022042119/5e97c784740f1608736f8070/html5/thumbnails/9.jpg)
Increased Vitamins Production• Folate
– Involved in biosynthesis of nucleotides– Daily recommended intake for an adult is 200 µg– Known to prevent neural-tube defect in infants– Protect against some forms of cancer
• Main sources are vegetables and dairy products• Milk is good source, fermented dairy products
like yoghurt are also important
![Page 10: An emerging field for metabolic engineering of Lactic Acid ...uni-lab.net/Materials/students/BSc-strains... · NUTRACEUTICALS: An emerging field for metabolic engineering of Lactic](https://reader034.vdocuments.us/reader034/viewer/2022042119/5e97c784740f1608736f8070/html5/thumbnails/10.jpg)
• Streptococcus thermophilus andLactococcus lactis execute de novobiosynthesis of folates to secrete surplusfolate
• Therefore can be used to make starter withincreased folate levels
• In experimental yoghurt up to 150 µg/L folatehas been reported
(Smid etal. 2001)
![Page 11: An emerging field for metabolic engineering of Lactic Acid ...uni-lab.net/Materials/students/BSc-strains... · NUTRACEUTICALS: An emerging field for metabolic engineering of Lactic](https://reader034.vdocuments.us/reader034/viewer/2022042119/5e97c784740f1608736f8070/html5/thumbnails/11.jpg)
![Page 12: An emerging field for metabolic engineering of Lactic Acid ...uni-lab.net/Materials/students/BSc-strains... · NUTRACEUTICALS: An emerging field for metabolic engineering of Lactic](https://reader034.vdocuments.us/reader034/viewer/2022042119/5e97c784740f1608736f8070/html5/thumbnails/12.jpg)
Part of Folate gene cluster L. lactiscloned behind strong promoter
![Page 13: An emerging field for metabolic engineering of Lactic Acid ...uni-lab.net/Materials/students/BSc-strains... · NUTRACEUTICALS: An emerging field for metabolic engineering of Lactic](https://reader034.vdocuments.us/reader034/viewer/2022042119/5e97c784740f1608736f8070/html5/thumbnails/13.jpg)
• The genes involved in folate biosynthesis have been
analysed completely.
• By genetic eng. several of these genes have been over
expressed in L.lactisNZ9000 using the NICE system
• Individual gene can be over expressed or in
combination
![Page 14: An emerging field for metabolic engineering of Lactic Acid ...uni-lab.net/Materials/students/BSc-strains... · NUTRACEUTICALS: An emerging field for metabolic engineering of Lactic](https://reader034.vdocuments.us/reader034/viewer/2022042119/5e97c784740f1608736f8070/html5/thumbnails/14.jpg)
• Folate normally synthesis as polyglutamyl-folatederivatives intracellularly
• Absorbed in human guts as monoglutamyl folatederivatives
• -glutamyl hydrolase cDNA introduced in L.lactis
• Resulted in an inversion of folate spatialdistribution
(Sybesma et al. 2002)
![Page 15: An emerging field for metabolic engineering of Lactic Acid ...uni-lab.net/Materials/students/BSc-strains... · NUTRACEUTICALS: An emerging field for metabolic engineering of Lactic](https://reader034.vdocuments.us/reader034/viewer/2022042119/5e97c784740f1608736f8070/html5/thumbnails/15.jpg)
![Page 16: An emerging field for metabolic engineering of Lactic Acid ...uni-lab.net/Materials/students/BSc-strains... · NUTRACEUTICALS: An emerging field for metabolic engineering of Lactic](https://reader034.vdocuments.us/reader034/viewer/2022042119/5e97c784740f1608736f8070/html5/thumbnails/16.jpg)
High production of folate by overexpression of whole fol gene cluster
![Page 17: An emerging field for metabolic engineering of Lactic Acid ...uni-lab.net/Materials/students/BSc-strains... · NUTRACEUTICALS: An emerging field for metabolic engineering of Lactic](https://reader034.vdocuments.us/reader034/viewer/2022042119/5e97c784740f1608736f8070/html5/thumbnails/17.jpg)
Folate production in engineeredLb. gasseri
![Page 18: An emerging field for metabolic engineering of Lactic Acid ...uni-lab.net/Materials/students/BSc-strains... · NUTRACEUTICALS: An emerging field for metabolic engineering of Lactic](https://reader034.vdocuments.us/reader034/viewer/2022042119/5e97c784740f1608736f8070/html5/thumbnails/18.jpg)
Folate level in the organs of animals depletedin folate and supplemented with LAB folate
![Page 19: An emerging field for metabolic engineering of Lactic Acid ...uni-lab.net/Materials/students/BSc-strains... · NUTRACEUTICALS: An emerging field for metabolic engineering of Lactic](https://reader034.vdocuments.us/reader034/viewer/2022042119/5e97c784740f1608736f8070/html5/thumbnails/19.jpg)
Riboflavin (B2)
• Riboflavin-deficiency can lead to:-– Liver(Ross & Klein 1990) and skin-disorders
(Lakshimi 1998)
– Disturbed metabolism of the red blood cells(Hassan & Thurnham 1977)
– Reduced performance during physical exercise(Belko et al. 1983; Bates 1987)
![Page 20: An emerging field for metabolic engineering of Lactic Acid ...uni-lab.net/Materials/students/BSc-strains... · NUTRACEUTICALS: An emerging field for metabolic engineering of Lactic](https://reader034.vdocuments.us/reader034/viewer/2022042119/5e97c784740f1608736f8070/html5/thumbnails/20.jpg)
![Page 21: An emerging field for metabolic engineering of Lactic Acid ...uni-lab.net/Materials/students/BSc-strains... · NUTRACEUTICALS: An emerging field for metabolic engineering of Lactic](https://reader034.vdocuments.us/reader034/viewer/2022042119/5e97c784740f1608736f8070/html5/thumbnails/21.jpg)
• In Bacillus subtilis first reaction in riboflavinbiosynthesis has been demonstrated to berate limiting
(Humbelin et al. 1999)
• The gene coding for this enzyme, ribA, hasbeen brought to overexpression in L. lactisusing the NICE-system
• This resulted in a 3-fold overproduction ofriboflavin
![Page 22: An emerging field for metabolic engineering of Lactic Acid ...uni-lab.net/Materials/students/BSc-strains... · NUTRACEUTICALS: An emerging field for metabolic engineering of Lactic](https://reader034.vdocuments.us/reader034/viewer/2022042119/5e97c784740f1608736f8070/html5/thumbnails/22.jpg)
Production of non-metabolisable sugars
• Mannitol and sorbitol (polyols) and trehalose couldreplace sucrose, lactose, glucose or fructose infood products
• In colon they are fermented by micro-organisms toshort-chain fatty acids (mainly butyrate) which mayprevent colon cancer
• Trehalose is therapeutic against illnesses, such asthe Creutzfeld-Jakob disease
![Page 23: An emerging field for metabolic engineering of Lactic Acid ...uni-lab.net/Materials/students/BSc-strains... · NUTRACEUTICALS: An emerging field for metabolic engineering of Lactic](https://reader034.vdocuments.us/reader034/viewer/2022042119/5e97c784740f1608736f8070/html5/thumbnails/23.jpg)
• Mannitol and sorbitol have stool-bulkingproperties and can be used as dietary fibers
• They are active as bifidogenic prebiotic
• Cholesterol lowering , immunomodulant
• They display equivalent sweetness and taste(Dwivedi 1978)
• Mannitol can also serve as anti-oxidant inbiological cells
(Shen et al. 1997)
![Page 24: An emerging field for metabolic engineering of Lactic Acid ...uni-lab.net/Materials/students/BSc-strains... · NUTRACEUTICALS: An emerging field for metabolic engineering of Lactic](https://reader034.vdocuments.us/reader034/viewer/2022042119/5e97c784740f1608736f8070/html5/thumbnails/24.jpg)
![Page 25: An emerging field for metabolic engineering of Lactic Acid ...uni-lab.net/Materials/students/BSc-strains... · NUTRACEUTICALS: An emerging field for metabolic engineering of Lactic](https://reader034.vdocuments.us/reader034/viewer/2022042119/5e97c784740f1608736f8070/html5/thumbnails/25.jpg)
Activation of Sorbitol production
![Page 26: An emerging field for metabolic engineering of Lactic Acid ...uni-lab.net/Materials/students/BSc-strains... · NUTRACEUTICALS: An emerging field for metabolic engineering of Lactic](https://reader034.vdocuments.us/reader034/viewer/2022042119/5e97c784740f1608736f8070/html5/thumbnails/26.jpg)
• Heterofermentative lactic acid bacteria such asLeuconostoc mesenteroides are known toproduce mannitol in the fermentation of fructose
(Soetaert et al. 1995)
• homofermentative lactic acid bacteria can alsoproduce mannitol
• In both Lactobacillus plantarum (Ferain et al.1996) and Lactococus lactis (Neves et al. 2000),disruption of lactate dehydrogenase (LDH)resulted in production mannitol along with othermetabolites
![Page 27: An emerging field for metabolic engineering of Lactic Acid ...uni-lab.net/Materials/students/BSc-strains... · NUTRACEUTICALS: An emerging field for metabolic engineering of Lactic](https://reader034.vdocuments.us/reader034/viewer/2022042119/5e97c784740f1608736f8070/html5/thumbnails/27.jpg)
![Page 28: An emerging field for metabolic engineering of Lactic Acid ...uni-lab.net/Materials/students/BSc-strains... · NUTRACEUTICALS: An emerging field for metabolic engineering of Lactic](https://reader034.vdocuments.us/reader034/viewer/2022042119/5e97c784740f1608736f8070/html5/thumbnails/28.jpg)
• Overproduction of the mannitol-P dehydrogenase(MPDH) in a LDH-deficient L. lactis strain hasresulted in strong increase in intracellular mannitolproduction
• Similar results were obtained when MPDH wasoverproduced in a strain with decreasedphosphofructokinase (PFK) activity
• Production of mannitol by Lactococcus lactis canbe increased if excretion of this polyol is facilitated,by introducing the mannitol-transporter present inLeuconostoc mesenteroides.
![Page 29: An emerging field for metabolic engineering of Lactic Acid ...uni-lab.net/Materials/students/BSc-strains... · NUTRACEUTICALS: An emerging field for metabolic engineering of Lactic](https://reader034.vdocuments.us/reader034/viewer/2022042119/5e97c784740f1608736f8070/html5/thumbnails/29.jpg)
Increasing Mannitol production
![Page 30: An emerging field for metabolic engineering of Lactic Acid ...uni-lab.net/Materials/students/BSc-strains... · NUTRACEUTICALS: An emerging field for metabolic engineering of Lactic](https://reader034.vdocuments.us/reader034/viewer/2022042119/5e97c784740f1608736f8070/html5/thumbnails/30.jpg)
Effect of pH on the production of mannitol and sorbitolby
Lb. plantarum VL202
![Page 31: An emerging field for metabolic engineering of Lactic Acid ...uni-lab.net/Materials/students/BSc-strains... · NUTRACEUTICALS: An emerging field for metabolic engineering of Lactic](https://reader034.vdocuments.us/reader034/viewer/2022042119/5e97c784740f1608736f8070/html5/thumbnails/31.jpg)
Tagatose production
• A potential sucrose replacement.
• Higher sweetening power than similar componentssuch as mannitol, sorbitol and erythritol
• Much lower caloric value
(Zehner 1988)
• Recently been launched on the food market as lowcalorie sugar, as prebiotic
![Page 32: An emerging field for metabolic engineering of Lactic Acid ...uni-lab.net/Materials/students/BSc-strains... · NUTRACEUTICALS: An emerging field for metabolic engineering of Lactic](https://reader034.vdocuments.us/reader034/viewer/2022042119/5e97c784740f1608736f8070/html5/thumbnails/32.jpg)
Calorific values of differentsugars
• Glucose 4.0 cal/gm• Mannitol 1.5 cal/gm• Sorbitol 2.5 cal/gm• Erythritol 0.2 cal/gm
![Page 33: An emerging field for metabolic engineering of Lactic Acid ...uni-lab.net/Materials/students/BSc-strains... · NUTRACEUTICALS: An emerging field for metabolic engineering of Lactic](https://reader034.vdocuments.us/reader034/viewer/2022042119/5e97c784740f1608736f8070/html5/thumbnails/33.jpg)
![Page 34: An emerging field for metabolic engineering of Lactic Acid ...uni-lab.net/Materials/students/BSc-strains... · NUTRACEUTICALS: An emerging field for metabolic engineering of Lactic](https://reader034.vdocuments.us/reader034/viewer/2022042119/5e97c784740f1608736f8070/html5/thumbnails/34.jpg)
• Chosen strategy is to disrupt the lacC and/orlacD genes resulting in production of eithertagatose-6-P or tagatose-1,6-diphosphate
• Disruption of lacD was accomplished via a twostep procedure
– recombination process, involving integration of anerythromycin-resistance plasmid containing only thelacC and lacF genes via single crossing-over
– removal of lacD (or reversion to the wild-type) in asecond, spontaneous, recombination event
![Page 35: An emerging field for metabolic engineering of Lactic Acid ...uni-lab.net/Materials/students/BSc-strains... · NUTRACEUTICALS: An emerging field for metabolic engineering of Lactic](https://reader034.vdocuments.us/reader034/viewer/2022042119/5e97c784740f1608736f8070/html5/thumbnails/35.jpg)
Production of polysaccharides
• Exopolysaccharides (EPS)
– Some polysaccharides produced by lacticacid bacteria have prebiotic
(Gibson & Roberfroid 1995)– Immunostimulatory
(Hosono et al. 1997)– Antitumoral
(Kitazawa et al. 1991)– Cholesterol-lowering activity
(Nakajima et al. 1992a)
![Page 36: An emerging field for metabolic engineering of Lactic Acid ...uni-lab.net/Materials/students/BSc-strains... · NUTRACEUTICALS: An emerging field for metabolic engineering of Lactic](https://reader034.vdocuments.us/reader034/viewer/2022042119/5e97c784740f1608736f8070/html5/thumbnails/36.jpg)
• The specific eps genes are encoded onlarge plasmids
• Conjugally transferred from onelactococcal strain to the next, therebyintroducing the EPS-producing capacity inthe recipient strain
( van Kranenburg et al. 1997)
![Page 37: An emerging field for metabolic engineering of Lactic Acid ...uni-lab.net/Materials/students/BSc-strains... · NUTRACEUTICALS: An emerging field for metabolic engineering of Lactic](https://reader034.vdocuments.us/reader034/viewer/2022042119/5e97c784740f1608736f8070/html5/thumbnails/37.jpg)
Polysaccharide gene cluster in variousLAB
![Page 38: An emerging field for metabolic engineering of Lactic Acid ...uni-lab.net/Materials/students/BSc-strains... · NUTRACEUTICALS: An emerging field for metabolic engineering of Lactic](https://reader034.vdocuments.us/reader034/viewer/2022042119/5e97c784740f1608736f8070/html5/thumbnails/38.jpg)
Improving sugar conversion
• In cow’s milk 4–4.5% (w/v) of lactosepresent
• In liquid fermented dairy products, suchas yoghurt or buttermilk, usually less thanhalf is fermented to lactic acid
• These products are unsuitable for lactoseintolerant persons
• The lactose is converted to galactose andlater to galactitol
![Page 39: An emerging field for metabolic engineering of Lactic Acid ...uni-lab.net/Materials/students/BSc-strains... · NUTRACEUTICALS: An emerging field for metabolic engineering of Lactic](https://reader034.vdocuments.us/reader034/viewer/2022042119/5e97c784740f1608736f8070/html5/thumbnails/39.jpg)
• For most lactic acid bacteria, galactose is apoor substrate
• The efficiency lactose utilization by L.lactiscan be increased by metabolic engineering
• Secondly lactose metabolism in L. lactis canbe modified in such a way that the glucosemoiety will end up in the product, whilegalactose will be fully used for growth, in thisway providing a natural sweetening processfor dairy products
![Page 40: An emerging field for metabolic engineering of Lactic Acid ...uni-lab.net/Materials/students/BSc-strains... · NUTRACEUTICALS: An emerging field for metabolic engineering of Lactic](https://reader034.vdocuments.us/reader034/viewer/2022042119/5e97c784740f1608736f8070/html5/thumbnails/40.jpg)
Galactose of Lactose being fully utilized andGlucose ends up in the product
![Page 41: An emerging field for metabolic engineering of Lactic Acid ...uni-lab.net/Materials/students/BSc-strains... · NUTRACEUTICALS: An emerging field for metabolic engineering of Lactic](https://reader034.vdocuments.us/reader034/viewer/2022042119/5e97c784740f1608736f8070/html5/thumbnails/41.jpg)
![Page 42: An emerging field for metabolic engineering of Lactic Acid ...uni-lab.net/Materials/students/BSc-strains... · NUTRACEUTICALS: An emerging field for metabolic engineering of Lactic](https://reader034.vdocuments.us/reader034/viewer/2022042119/5e97c784740f1608736f8070/html5/thumbnails/42.jpg)
• Free galactose is accumulated intracellularly as aresult of the absence of galactokinase activity inthese strains
• Streptococcus thermophilus, gene forgalactokinase is completely intact, but that one ormore point mutations have taken place leading to a‘silent’ phenotype (Vaughan et al. 2001).
• Sometimes these mutations may revert backspontaneously
• To enhance the galactose utilization thesemutations can be reverted deliberately
![Page 43: An emerging field for metabolic engineering of Lactic Acid ...uni-lab.net/Materials/students/BSc-strains... · NUTRACEUTICALS: An emerging field for metabolic engineering of Lactic](https://reader034.vdocuments.us/reader034/viewer/2022042119/5e97c784740f1608736f8070/html5/thumbnails/43.jpg)
- Galactosides and their hydrolyticenzymes
![Page 44: An emerging field for metabolic engineering of Lactic Acid ...uni-lab.net/Materials/students/BSc-strains... · NUTRACEUTICALS: An emerging field for metabolic engineering of Lactic](https://reader034.vdocuments.us/reader034/viewer/2022042119/5e97c784740f1608736f8070/html5/thumbnails/44.jpg)
Removal of raffinose
• Soy- and pulse-derived food products containhigh levels of -galactosides such as stachyoseand raffinose
• These are not metabolized in human gut due tolack of - galactosidase
• These undigested - galactosides accumulate inthe lower gut and induce gastric problems likeflatulence
![Page 45: An emerging field for metabolic engineering of Lactic Acid ...uni-lab.net/Materials/students/BSc-strains... · NUTRACEUTICALS: An emerging field for metabolic engineering of Lactic](https://reader034.vdocuments.us/reader034/viewer/2022042119/5e97c784740f1608736f8070/html5/thumbnails/45.jpg)
• By applying metabolic engineering strategies, lacticacid bacteria can be constructed with high -galactosidase activities
• Starters for removal of -galactosides during soyfermentation
• Possible probiotics to deliver -galactosidaseactivity in the gut for prevention of flatulence
• In Lactobacillus plantarum gene (melA) code for-galactosidase
(Silvestroni et al. 2002)
![Page 46: An emerging field for metabolic engineering of Lactic Acid ...uni-lab.net/Materials/students/BSc-strains... · NUTRACEUTICALS: An emerging field for metabolic engineering of Lactic](https://reader034.vdocuments.us/reader034/viewer/2022042119/5e97c784740f1608736f8070/html5/thumbnails/46.jpg)
• For construction of starter and probiotic bacteriawith high -galactosidase activity, the melA iscloned in L. lactis in three different constructionsresulting in
– expression of the enzyme in the cytoplasm formaximum protection of enzyme activity
– expression as a secreted enzyme for maximumexposure to the sugar substrate
– expression on the surface but anchored to thesurface of the cell
![Page 47: An emerging field for metabolic engineering of Lactic Acid ...uni-lab.net/Materials/students/BSc-strains... · NUTRACEUTICALS: An emerging field for metabolic engineering of Lactic](https://reader034.vdocuments.us/reader034/viewer/2022042119/5e97c784740f1608736f8070/html5/thumbnails/47.jpg)
Conclusion• Metabolic engineering has provided a powerful
and effective tool for production of nutraceuticals
• Metabolic engineering approach can also beapplied for production of more benificial product.
• With increasing knowledge of the genomicanalysis metabolic engineering can further beexplored for more nutraceutical production.