Indian Journal of Chemical Technology, Vol.19, No.1, 63-70, 2012
Bioethanol fermentation from untreated and pretreated lignocellulosic wheat straw using fungi Fusarium oxysporum
A comparison has been made among untreated, lime pretreated and dilute alkaline peroxide pretreated wheat straw for bioethanol production by simultaneous saccharification and fermentation (SSF) process in a continuous stirred batch bioreactor (CSBR) using fungi Fusarium oxysporum. The optimum parameters used for the bioethanol fermentation are: time 48 h, pH 6, temperature 50. stirring speed 35, and wheat straw loading 35 g/L. Maximum yield of ethanol is found to be 0.756. 0.796 and 0.810 g/g of wheat straw under optimum conditions for untreated, lime pretreated and dilute alkaline peroxide pretreated wheat straw. The sp. fungal growth rate is found to be 5.26, 5.40, and 5.88 s(-1) and maximum sp. fungal growth rate is 10.52, 10.80 and 11.76 s(-1) using the Monod model for the fermentation of untreated, lime pretreated and dilute alkaline peroxide pretreated wheat straw under optimum conditions respectively. The fungal growth kinetic parameters are 33.6, 33.9 and 34.7 g/L respectively for fermentation of the three samples under the optimum conditions. The sp. carboxy methyl cellulase (CMCase) activity are 1185, 1455 and 1545 min(-1) and maximum sp. CMCase activity are 2370, 2910 and 1545 min(-1) using Michaelis-Menten enzyme kinetic model for the fermentation of three samples respectively under optimum conditions. The CMCase enzyme kinetic parameters are 34.3, 34.5 and 34.7 g/L for the three samples respectively under optimum fermentation conditions. Fungi Aspergillus oryzae show the better conversion of ethanol than fungi Fusarium oxysporum. The fermentation process follows the first order rate equation in CSBR.