Enzymatic conversion of lignocellulose into fermentable sugars: challenges and opportunities
The economic dependency on fossil fuels and the resulting effects on climate and environment have put tremendous focus on utilizing fermentable sugars from lignocellulose, the largest known renewable carbohydrate source. The fermentable sugars in lignocellulose are derived from cellulose and hemicelluloses but these are not readily accessible to enzymatic hydrolysis and require a pretreatment, which causes an extensive modification of the lignocellulosic structure. [1]
An Oxidative Enzyme Boosting the Enzymatic Conversion of Recalcitrant Polysaccharides
Efficient enzymatic conversion of crystalline polysaccharides is crucial for an economically and environmentally sustainable bioeconomy but remains unfavorably inefficient. We describe an enzyme that acts on the surface of crystalline chitin, where it introduces chain breaks and generates oxidized chain ends, thus promoting further degradation by chitinases [2]
Enzymatic conversion of proteins to glycoproteins
The enzymatic transfer of the oligosaccharide moiety from an oligosaccharide-lipid to denatured forms of three secretory proteins–ovalbumin, alpha-lactalbumin, and ribonuclease A–has been demonstrated utilizing a membrane fraction from hen oviduct. [3]
Enzymatic Conversion of Waste (Rice Husk) into Fermentable Sugar through Diluted Acid Pretreatment
The enzymatic production of fermentable-sugar from rice husk was examined using diluted sulfuricacid as a pretreatment medium. In this study, 10 g of rice husk were separately pretreated with 0.5 M, 1.0 M and 1.5 M sulfuric acid at different time interval of 2-24 hours, prior to saccharification by cellulase-enzyme at 37°C and pH of 4.5. Then the quantity of m onosaccharide produced was determined spectrophotometrically . [4]
Waste Paper as Promising Feedstock for Production of Biofuel
Modern approach to utilization of non-edible biomass is its conversion to glucose, and the following fermentation of the sugar into final bioproducts. Among various biomass types, the waste of office paper is distinguished by increased content of cellulose and negligible content of lignin; therefore it can be a suitable feedstock for bioconversion into valuable bioproducts. In this article, an advanced technology has been proposed for complete utilization of the paper waste by bioconversion. [5]
Reference
[1] Jørgensen, H., Kristensen, J.B. and Felby, C., 2007. Enzymatic conversion of lignocellulose into fermentable sugars: challenges and opportunities. Biofuels, Bioproducts and Biorefining, 1(2), pp.119-134.
[2] Vaaje-Kolstad, G., Westereng, B., Horn, S.J., Liu, Z., Zhai, H., Sørlie, M. and Eijsink, V.G., 2010. An oxidative enzyme boosting the enzymatic conversion of recalcitrant polysaccharides. Science, 330(6001), pp.219-222.
[3] Pless, D.D. and Lennarz, W.J., 1977. Enzymatic conversion of proteins to glycoproteins. Proceedings of the National Academy of Sciences, 74(1), pp.134-138.
[4] Okpe, O., Isaac, T.O., Okoduwa, S.I.R., Omoregbe, F.B. and Ezeiru, C.C., 2016. Enzymatic Conversion of Waste (Rice Husk) into Fermentable Sugar through Diluted Acid Pretreatment. Asian Journal of Environment & Ecology, pp.1-6.
[5] Ioelovich, M. (2014) “Waste Paper as Promising Feedstock for Production of Biofuel”, Journal of Scientific Research and Reports, 3(7), pp. 905-916. doi: 10.9734/JSRR/2014/8025.