Depolymerization of bagasse by Ruminococcus albus in the production of eco-friendly fuel

Ethanol production by fermentation of lignocellulosic biomass-derived sugarsinvolves a fairly ancient art and an ever-evolving science. Production of ethanol fromlignocellulosic biomass is not avant-garde, and wood ethanol plants have been inexistence since at least 1915. Most current ethanol production relies on starch- and sugarbasedcrops as the substrate; however, limitations of these materials and competing valuefor human and animal feeds is renewing interest in lignocellulose conversion.Lignocellulosic biomass contains carbohydrate fractions that can be converted intoethanol. In order to convert these fractions, the cellulose and hemicelluloses mustultimately be converted or hydrolysed into monosaccharides; it is the hydrolysis that hashistorically proven to be problematic. Biologically mediated processes are promising forenergy conversion, in particular for the conversion of lignocellulosic biomass into fuels.The objective of the present study is to optimise cellulosic ethanol production frombagasse by using Ruminococcus albus isolated from rumen of herbivores animals. Theprocessing and utilization of the lignocellulosic substrate is complex, differing in manyaspects from crop-based ethanol production. Since the scientific dogma states that thebreakdown or depolymerisation of lignocellulose can be achieved only by chemical or byenzymatic approach; in the present study we isolated Ruminococcus albus from rumenanimals which was depolymerise cellulose and hemicellulose as well as to tolerate stressconditions. Optimum temperature, pH and substrate concentration for depolymerizationwere 390C, 8.8 and 3.5% respectively for Ruminococcus albus. For the feed stock ofconcentration 3.5%, ethanol yield of 19.8g/l was obtained.