Fermentation of Biomass for Production of Ethanol: A Review

The Present world energy scenario is focused at nonconventional sources. The biomass has emerged as one of the dependable nontraditional feed stocks for the production ethanol. The present review enlighten various feed stocks viz. sugar beets, sugar cane corn, wheat, barley etc. and fermentation methods for the production of ethanol. The use of biomass for clean energy generation in the European Union is expected to increase nearly 35% by the end of 2030 without harming biodiversity, soil and water resources. Ethanol can be produced from appreciable amount of sugar or material that can be converted into sugar such as starch or cellulose. Industrial ethanol producing microorganisms which are capable of fermenting all of the sugar present in feed stock; attracted much attention in recent years with the recent advances in biotechnology. Saccharomyces cerevisiae (yeast) is naturally unable to ferment pentose; its capability for xylose utilization has successfully been improved by intensive research over the last decades. During the last fifteen years, research has been focused on finding these xylose-fermenting microorganisms. S. cerevisiae has an efficient anaerobic sugar metabolism, tolerates inhibitory industrial substrates better than other microorganisms and ferments hexoses abundantly present in lignocellulosic hydro lysates with high yield and productivity. Attempts have also been made to review the status of fermentation of forest, industrial residue, agriculture waste and municipal solid waste. The present efforts are expected to enhance world energy scenario and