Optimization of Pretreatment, Enzymatic  Saccharification and Fermentation Conditions for  Bioethanol Production from Rice Straw

Gurvinder Singh Kocher; Krishan Lal Kalra

Volume : III, Issue : V, May - 2013

Optimization of Pretreatment, Enzymatic Saccharification and Fermentation Conditions for Bioethanol Production from Rice Straw

Gurvinder Singh Kocher, Krishan Lal Kalra

Abstract :

Pretreatment of rice straw was optimized by soaking it in 2% H2SO4 (1:8) followed by autoclaving at 15 psi for 90 min resulting in 25% solubility of cellulose along with decrease in hemicelluloses and lignin contents. Pretreatment also released 70.5 mg xyloses and 296.2 mg hexoses per gram of straw in the acidic solution that upon fermentation with a co culture (5% v/v) of S.cerevisiae and P.tannophilus (1:1) produced 0.98%, v/v of ethanol. Saccharification of pretreated rice straw, optimized [S] and [E] revealed 5% substrate and 15 FPU of partially purified enzyme, yielding 41.8% saccharification efficiency. The fermentation of saccharified rice straw produced 0.67%, v/v ethanol at a fermentation efficiency of 78.6%. The validation of fermentation of saccharified rice straw to 3 L (@ 200g straw) revealed 6.1g of absolute alcohol at a fermentation efficiency of 55%.