Consolidated bio-saccharification: Leading lignocellulose bioconversion into the real world

Lignocellulosic biomass is the most abundant sustainable carbon source on the planet and has enormous potential to substitute fossil resources on the premise of cost-effective conversion. Efforts have been made to develop various lignocellulosic bioconversion strategies to overcome biomass recalcitrance, promote product conversion efficiency and reduce process cost. Consolidated bio-saccharification (CBS), a consolidated bioprocessing (CBP) derived strategy, is herein proposed for lignocellulose bioconversion by integrating enzyme production and hydrolysis steps but separating fermentation from the integrated process. This strategy employs cellulosome-producing microorganisms as a biocatalyst to enhance lignocellulose solubilization and produces lignocellulose-derived fermentable sugars as a platform product for fermentations aiming at various products. The success of CBS depends on robust biocatalysts with high activity, suitable pretreatments for efficient delignification, and downstream fermentations with process compatibility. The review introduces the updated progress on lignocellulose bioconversion following the CBS route, discusses key factors for optimization of the CBS process, and, more importantly, highlights challenges and promising solutions for the CBS strategy in the industrial application of lignocellulose bioconversion.