Advances in Pretreatment of Straw Biomass for Sugar Production

Abstract

Straw biomass is an inexpensive, sustainable, and abundant renewable feedstock for the production of valuable chemicals and biofuels, which can surmount the main drawbacks such as greenhouse gas emission and environmental pollution, aroused from the consumption of fossil fuels. It is rich in organic content but is not sufficient for extensive applications because of its natural recalcitrance. Therefore, suitable pretreatment is a prerequisite for the efficient production of fermentable sugars by enzymatic hydrolysis. Here, we provide an overview of various pretreatment methods to effectively separate the major components such as hemicellulose, cellulose, and lignin and enhance the accessibility and susceptibility of every single component. This review outlines the diverse approaches (e.g., chemical, physical, biological, and combined treatments) for the excellent conversion of straw biomass to fermentable sugars, summarizes the benefits and drawbacks of each pretreatment method, and proposes some investigation prospects for the future pretreatments.

Improving the Substrate Affinity and Catalytic Efficiency of β-Glucosidase Bgl3A from Talaromyces leycettanus JCM12802 by Rational Design

“…The difference value between G complex and (G receptor + G ligand ) was considered the change in Gibbs free energy caused by the binding process, which is approximately equal to the binding energy of the receptor-ligand complex. Thus, the binding free energy (G binding ) was calculated according to the following formula Equation (2):…”

“…Additionally, it represents the most valuable source of renewable energy and raw materials [ 1 ]. The worldwide consensus is that the efficient utilization of cellulosic agricultural wastes is critical in generating sustainable biofuel production methods [ 2 ]. The enzymatic degradation of cellulose to glucose is generally accomplished by a synergic action of three kinds of glycoside hydrolases, such as endo-β-glucanase (EG, EC 3.2.1.4), cellobiohydrolase (CBHs, EC 3.2.1.91), and β-glucosidase (BGLs, EC 3.2.1.21) [ 3 , 4 ].…”

Response mechanisms of Saccharomyces cerevisiae to the stress factors present in lignocellulose hydrolysate and strategies for constructing robust strains

“…Biomass is one of the most abundant and renewable resource, which plays an important role to reduce the net CO 2 emission [ 2 , 3 ]. Lignocellulose is a major type of biomass with an estimated yield of hundreds of billions tonnes annually [ 4 ], which mainly includes herbaceous straws (e.g., crop straws [ 5 ], bagasse [ 5 ], leguminosae [ 6 – 8 ], solanaceae [ 9 ], sunflower [ 10 ], etc. ), woody biomass (e.g., p aulo wni a tomentosa [ 11 ], poplar [ 12 ], etc., and various forestry residues), energy crops (e.g., miscanthus and switchgrass [ 13 ], etc.)…”

“…[ 14 ], and livestock and poultry dung [ 15 ]), lignocellulosic biomass has significant advantages like quick production, wide availability, low cost, and without interfering with food security [ 16 ]. It has been estimated that plenty of straws with total yield of 3165 million tonnes are produced as agricultural residues every year in the world [ 5 ]. Therefore, various technologies have been developed to convert lignocellulosic biomass to biofuels (e.g., bioethanol, butanol, CH 4 , H 2 , etc.)…”

Recyclable Zr/Hf-Containing Acid-Base Bifunctional Catalysts for Hydrogen Transfer Upgrading of Biofuranics: A Review

“…However, compared to the desired products especially for fuels or fuel additives, biomass-derived feedstocks generally possess higher oxygen content (Prasomsri et al, 2013;Liao et al, 2014;Li et al, 2020a;Li et al, 2020b;Wang et al, 2020a). It is still necessary to further process the biomass feedstock to upgrade its functional groups (Dabros et al, 2018;Li et al, 2019b;Iglesias et al, 2020Tan et al, 2021. In the field of biomass upgrading, the most widely used approach is to convert biomass (e.g., cellulose and hemicellulose) into a series of furan compounds via cascade reactions (Scheme 1) (Zhou and Zhang, 2016;Liu et al, 2019;Chen et al, 2021b).…”