Processing sweet sorghum into bioethanol - an integrated approach

Abstract

Numerous evidences have been provided that juice of sweet sorghum and the leftover after squeezing, the bagasse can be a proper feedstock for bioethanol production. The possibility to integrate a side stream of sweet sorghum processing into the biomass-to-ethanol process was investigated in this study. The liquid fraction, a side stream of the necessary pretreatment of the bagasse was utilized as carbon source for Trichoderma reesei RUT-C30 to produce cellulase enzymes for biomass conversion. However, to overcome the inhibitory nature of the liquid fraction, pre-adaptation of the fungus on solid media was carried out previous to submerged fermentations. The results show that with this approach the lag phase caused by the inhibitors could be markedly shortened and an enhancement of the final enzyme production could be achieved when comparing the pre-adapted strains to reference.