Ethanol production using the whole solid-state fermented sugarcane bagasse cultivated by Trichoderma reesei RUT-C30 supplemented with commercial cellulase.

Industrial ethanol production usually requires the costly use of commercial cellulase. Herein, we describe the direct use of cellulase produced by Trichoderma reesei RUT-C30 with sugarcane bagasse (SCB) as a substrate for the production of ethanol. The pretreated SCB supplemented with wheat bran (weight ratio of 4:1) was used for T. reesei cellulase production by solid-state fermentation. The cellulase activity titers of 5.5 ± 0.7 FPU/gdm was achieved. The activity increased to 15.0 ± 0.9 FPU/gdm when lactose was used as an inducer. The cellulase contained SCB (CSCB) was used directly as the raw material for ethanol production by Kluyveromyces marxianus at 40 °C, yielding 14.1 ± 1.8% (w/w) of ethanol. Supplementing 5 FPU/gdm of commercial cellulase (Cellic® CTec 2) to CSCB improved the ethanol yield to 30.3 ± 0.4% (w/w). Supplementing Cellic® CTec 2 provided large amount of β-glucosidase activity to CSCB, which hydrolyzes cellobiose to glucose, thereby preventing the inhibition of cellobiose to exoglucanase and endoglucanase. This study demonstrate the feasibility of integrating direct utilization of CSCB without further processing, conversion of CSCB to fermentable sugars, and fermentation of yeast to ethanol in a single reactor. This may be the most efficient way to convert biomass to valuable ethanol. • Production of cellulase by solid-state fermentation of Trichoderma reesei RUT-C30 using bagasse as the main substrate. • Addition of lactose to bagasse can increase the activity of cellulase by 1.7 times. • The fermented bagasse containing cellulase is used directly for ethanol production. • Addition of commercial cellulase (Cellic® CTec2) increases alcohol yield in fermented bagasse. [ABSTRACT FROM AUTHOR]