Cyber Times International Journal of Technology & Management

An attempt has been made to increase ethanol production from rice bran (RB) and wheat bran (WB). RB and WB were hydrolyzed by hydrothermal pre-treatment followed by enzymatic treatment by cellulose enzyme produced by Micrococcus luteus VSG-5 prior to fermentation. The growth medium and culture conditions with low cost substrates (RB and WB), temperature and initial pH were optimized for the fermentation of alcohol. The effect of nitrogen source on production of alcohol was also investigated, fish protein seems to be the best nitrogen source than the yeast extract as is it a cheap source. The hydrolysates underwent sequential fermentations using two different microorganisms (S. cerevisiae and C. tropicalis) to produce bio-ethanol. WB hydrolysate was found to be the best media for bio-ethanol (27.34g/l; 0.379g/l/h) production when fermented with C. tropicalis as compared to RB alcohol (26.56g/l). For all hydrolysates, S. cerevisiae grew more; however, it produced less alcohol than C. tropicalis (15.08 and 14.26g/l from RB and WB respectively).