Cellulases For Biomass Degradation

Cellulases for biomass degradation

Biomass is biological material derived from living or recently living organisms. Degradation of cellulosic biomass is occurred by mixtures of hydrolytic enzymes, all together known as cellulases. Biomass can be used as a source of biofuels, such as cellulosic ethanol. Cellulases are derived from certain fungi and bacteria. Currently, these bacterial and fungal cellulases use in saccharification, but there are limitations such as, low activity under conditions in biorefineries, inhibition by co-products and high cost of production. Thus, development of cellulase expression is effect to change the nature of the biofuel industry2.Using recombination we can improve the cellulase enzyme expression. Here examine the development of,

Bacteria expression system Plant expression system

Yeast expression system Fungal expression system

Discuss recombinant cellulase expression platforms, current strategies for producing cellulases, benefits and drawbacks in yield, stability and activity of enzymes from each system1.

Recombinant bacterial systems for cellulase production

Several gram negative bacteria such as E.Coli, Klebsiella oxytoca, Zymomonas mobilis have been engineered for ethanol production.Commonly used bacteria for recombinant cellulase enzyme expression is E. coli. Recombinant production of cellulases in bacteria increase the enzyme yield, compared to the original host. These changes involving gene copy number, promoters and inducer types3.

Genome reduction in Bacillus subtilis, reached by stepwise gene deletion and it increase the cellulase production and organism growth efficiency. These cellulase expressing bacterial organisms are stable and active under industri...

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... cellulases expression performed at high concentration and retaining similar activity and stability to the native forms. Kluyveromyces lactis can secrete high yield heterologous cellulase use in enzymatic pretreatment strategies.

References

(1) Garvey, M.; Klose, H.; Fischer, R.; Lambertz, C.; Commandeur, U. Cellulases for Biomass Degradation: Comparing Recombinant Cellulase Expression Platforms. Trends Biotechnol. 2013, 31, 581–593.

(2) Wieczorek, A. S.; Biot-pelletier, D.; Martin, V. J. J. Recombinant Cellulase and Cellulosome Systems. 2013.

(3) Bock, R. Transgenic Plastids in Basic Research and Plant Biotechnology. J. Mol. Biol. 2001, 312, 425–438.

(4) Quiroz-castañeda, R. E.; Folch-mallol, J. L. Hydrolysis of Biomass Mediated by Cellulases for the Production of Sugars.2013.

(5) Zhang, X.; Zhang, Y. P. PRODUCTION , AND APPLICATIONS. 2013, 131–146.