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
life on the planet.