Fungal biotreatment of agro-industrial wastes for the production of bioethanol in bioreactor

ABSTRACT

BIOETHANOL production from lignocellulosic feedstocks is considered a promising strategy to increase global production of biofuels without impacting food supplies. This work aimed to evaluate bioethanol production by baker's yeast using a medium containing the hydrolysate of fungal biotreatment of five different lignocellulosic feedstocks with some amendments. The pretreatment of lignocellulosic feedstocks using 5 % w/v NaOH, 1 % v/v H[2]SO[4] and sodium hypochlorite H[2]O[2][101] prior to fungal biotreatment was studied. For bioethanol production, batch, fed-batch [two strategies] and continuous cultivations of baker's yeast on the fungal biotreated rice straw hydrolysate was evaluated in bioreactor. In batch and pulsed fed-batch cultivations, the highest bioethanol concentration, conversion coefficient, bioethanol yield and productivity were [0.41 % v/v, 36.9 % v/w, 36,9 % v/w and 0.114 ml/l/h, respectively], while in fed-batch cultivation with continuous feeding these parameters were [0.45 % v/v, 40 % v/w,. 40.5 v/w % and 0,015 ml/l/h, respectively]. The highest bioethanol concentration [0.52 % v/v] was obtained in continuous culture at dilution rate of 0.03 h[-1]. while conversion coefficient; yield and productivity were 31.2 % v/w, 31.4 % v/w and 0.022 ml/l/h, respectively