Bioprocess engineering of bioethanol production based on sweet sorghum bagasse by co-culture technique using Trichodermareesei and Saccharomyces cerevisiae

Abstract

The objective of this study was to investigate the technique to produce bioethanol by co-culture of Trichoderma reesei and Saccharomyces cerevisiae on sweet sorghum bagasse which has higher yield and productivity of bioethanol. Sweet sorghum bagasse contains 48.65?0.02% cellulose. Cultivation of Trichoderma reseei on sweet sorghum bagasse produced the highest concentration of sugar (10.90?0.05 g L -1 )at 36 th hours of cultivation. The time at which highest concentration of sugar produced, is used to apply the bioprocess engineering to allow high production of bioethanol by Saccharomyces cerevisiae. The bioprocess engineering of co-culture technique was conducted by switching condition from aerobic to anaerobic and inoculation of Saccharomyces cerevisiae inoculums at 36 th hours of Trichoderma reseei cultivation. As a comparison, bioethanol production was conducted using conventional technique in which co-culture of T. reseei and S. cerevisiae from the beginning of fully aerobic cultivation without switching conditions. The results showed that bioethanol production produced was higher than that of conventional technique ( 7.99?0.62 g L -1 compared to 6.60?0.28g L -1 ). The yield of product formation (Yp/s) using this technique was 0.30?0.08 g bioethanol/g substrate which was higher compared to conventional technique (0.17?0.01 g bioethanol/g substrate). Bioethanol production rate using this technique was 1.48 ? 0.03 g L -1 , hour -1 which was higher compared to conventional technique (1.04 ? 0.06g L -1 hour -1 ).