The effect of TiO2-photocatalytic pretreatment on the biological production of ethanol from lignocelluloses

In biological production of EtOH from lignocellulose such as napiergrass (Pennisetum purpureum Schumach; 1a) and silver grass (Miscanthus sinensis Anderss, 1b), the effect of the photocatalytic pretreatment with TiO2 (PC-pretreatment) to enzymatic saccharification by Acremozyme cellulase (SA-reaction) and fermentation by Saccharomyces cerevisiae (FE-reaction) was examined. The PC-pretreatment was remarkably effective for the shortening of the reaction time in the SA and FE reactions compared with the other pretreatments such as no pretreatment (NO-treatment) and pretreatment with NaOH (AL-pretreatment). However, the PC-pretreatment did not affect to the final product distribution. The PC → SA → FE process converted holocellulose (44 g) of 1a to 7.5 g of EtOH. Also, the PC → SA → FE process of holocellulose (41 g) of 1b produced EtOH in 5.5 g.

► A first finding on the photocatalytic (PC) pretreatment of TiO2 for bio-ethanol production.
► PC pretreatment shortened the reaction time of saccharification of lignocellulose by cellulase.
► PC pretreatment shortened the reaction time of fermentation by yeast.