Introduction: Energy conversion, utilization and access underlie many of the great challenges of our time, including those associated with sustainability, environmental quality, security and poverty. New applications of emerging technologies are required to respond to these challenges. Biotechnology one of the most powerful of the emerging technologies, can give rise to important new energy conversion processes. Plant biomass and derivatives thereof are a resource for the biological conversion of energy to forms useful to humanity. Among forms of plant biomass, lignocellulosic biomass is particularly well-suited for energy applications because of its large-scale availability, low cost and environmentally benign production. In particular, many energy production and utilization cycles based on cellulosic biomass have near zero greenhouse gas emissions on a life cycle basis. The primary obstacle impeding the more widespread production of energy from biomass feedstock is the general absence of low cost technology for overcoming the recalcitrance of these materials to conversion into useful fuels. Lignocellulosic biomass contains carbohydrate fractions that can be converted to ethanol. In order to convert these fractions, the cellulose and hemicellulose must ultimately be converted or hydrolysed into monosaccharides; it is the hydrolysis that has historically proven to be problematic. The proposal relates to an efficient, cost-effective and environment-friendly process for production of alcohol, and allied down-stream products from lignocellulosic feed.

Objectives, Methods and Results: The objective of the present study was to optimise cellulosic ethanol production from bagasse by using rumen bacteria isolated from herbivores animals. The processing and utilization of the lignocellulosic substrate is complex, differing in many aspects from crop-based ethanol production. Since the scientific dogma states that the breakdown or depolymerisation of lignocellulose can be achieved only by chemical or by enzymatic approach; in the present study rumen isolates could easily depolymerise cellulose and hemicellulose as well as multiply efficiently in in-vitro conditions. Optimum temperature, pH for depolymerisation ranged from 38-39⁰C, 7.8 to 8.2 respectively for different rumen isolates. Ethanol concentration of 4.5% to 6.2% were achieved in our study. Genetic modification of ruminant bacteria into E.coli yielded around 6.8 to 7.2% ethanol.

Conclusions: To conclude The gut of ruminant herbivorous animals are rich in bacteria that convert the lignocellulosic biomass ingested by these animals into simple glucose, which can be exploited for ethanol production. However, our studies have revealed that these naturally occurring bacteria will not yield high percentage of glucose required for the commercially viable production of ethanol. However, by molecular cloning and expressing the genes encoding the enzymes such as cellulase from ruminant gut bacteria in E.coli or by genetically modifying important cellulolytic anaerobic bacteria enhanced production of glucose from lignocellulosic biomass. The glucose thus obtained were converted to ethanol by standard downstream technologies.