Microbial saccharification - Biorefinery platform for lignocellulose

Lignocellulosic biomass has gained increasing attention as it can be bio-transformed into biofuel, such as bioethanol, biobutanol, biohydrogen, biogas and biodiesel. The conventional strategy includes the biotransformation of lignocellulose into soluble and fermentable sugars through enzymatic hydrolysis for bioenergy production. However, the exogenous cellulase reagent preparation leads to increased complexity and a high saccharification cost. Microbial saccharification (MS) can also realize in-situ simultaneous enzymatic production and hydrolysis to obtain value-added products in a single step. However, its application is limited due to the high temperature of enzymatic hydrolysis than the optimum growth and enzyme synthesis temperature of most natural microorganisms. Nevertheless, some microbial strains and consortiums with excellent potential for microbial saccharification have been discovered and developed. Therefore, this review comprehensively summarizes different microorganisms with MS strategies, including natural and modified strains, the limitations of different strains, and possibilities for industrial application.