Efficient sugar production from plant biomass: Current status, challenges, and future directions

Lignocellulosic plant biomass is recognized as an alternative resource for sustainable production of liquid fuels, chemicals, and polymeric materials through the biorefining concept. The sugar platform is one of the promising approaches for commercial conversion of cellulose and/or hemicelluloses in plant biomass into the targeted products biologically and/or chemically through carbohydrate saccharification. However, efficient, and sustainable sugar production from lignocellulose remains a great challenge because of the natural recalcitrance of lignocellulose to deconstruction. This review aims to provide current understanding of the key barriers to lignocellulose saccharification, a critical assessment of the available technologies for sugar production from lignocellulose, including chemical and enzymatic approaches, and potential strategies to overcome the recalcitrance for commercial development. Special attention is paid to lignin-induced inhibition to enzymatic hydrolysis of lignocellulosic substrates and pretreatment/fractionation methods to overcome or decrease biomass recalcitrance. Perspectives and future research needs are also presented