The Efficient Co-culture Fermentation Process for Producing 2G Bioethanol

Abstract

2G Bioethanol production from lignocellulosic materials constitutes a promising and sustainable source of clean energy which has received a lot of attention last decade. In the fermentation process, the presence of different natures sugars, mainly glucose and xylose, constitute the main challenge. Co-culture fermentation of lignocellulosic hydrolysates, has been considered a promising technology, which makes it possible to have a bioethanol process with more cost efficiency, and with widespread commercialization. The present work deals with the study of the co-culture fermentation process efficiency, on an industrial scale. A simulation tool of a trial version of SuperPro Designer software was used, to compare between Saccharomyces cerevisiae / Pichia stipitis (A), Escherichia coli strain ALS1008 E. coli strain ZSC113 (B), and S. cerevisiae / E. coli strain ZSC113 (C). These systems allowed fermentation of lignocellulosic hydrolysates obtained using dilute sulfuric acid in pretreatment and hydrolysis steps and characterized by resisting low value of pH, and high concentration of inhibitors. The performance of the studied systems was examined and compared by taking the overall ethanol productivity (Retoh) as the basic comparison parameter. The best results were obtained from the system (A), it gave a Retoh equal to 0.45 (g/L.h). The systems (B) and (C) have given, successively, 0.26 (g/L.h) and 0.22 (g/L.h).