Consolidated bioprocessing of lignocellulose by a microbial consortium

Abstract

Lignocellulosic biomass is uniquely suited as a sustainable feedstock for the biotechnological production of alternative fuels and chemicals. However, due to the biomass recalcitrance, the enzymatic conversion process is complex and needs to be simplified. To this end, we developed a process, which allows the consolidated bioprocessing of lignocellulose to ethanol in a single multi-species biofilm membrane reactor featuring both aerobic and anaerobic conditions necessary for the simultaneous fungal cellulolytic enzyme production and alcoholic yeast fermentation of the hydrolysis-derived sugars. The general feasibility of the concept was successfully demonstrated by producing ethanol with a 67% yield from undetoxified whole slurry dilute acid pretreated wheat straw by the combined action of Trichoderma reesei, Saccharomyces cerevisiae and Scheffersomyces stipitis. The results achieved underscore the potential of the process as a versatile cheap sugar platform for the production of fuels and chemicals based on lignocellulosic biomass by specifically compiled consortia of industrially proven robust microorganisms.