INTRODUCTION
The useful physiological properties of yeast have led to their use in the field of
biotechnology, fermentation of sugars by yeast being the oldest and largest application of
this technology. Many types of yeasts are used for making many foods: baker's yeast in
bread production; brewer's yeast in beer fermentation; yeast in wine fermentation and for
xylitol production. A worldwide interest in the utilization of bio-ethanol as an energy source
has stimulated studies on the cost and efficiency of industrial processes for ethanol
production. Intense research has been carried out for obtaining efficient fermentative
organisms, low-cost fermentation substrates and optimum environmental conditions for
fermentation to occur. Traditionally, ethanol production is usually accomplished by
microbial conversion of carbohydrates present in agricultural products1. As, few yeast strains
have been found to possess appreciable characteristics for ethanol production2,3, there is a