木质纤维素生物质已经成为一种有前途的环境资源。酶催化,作为各种治疗方法中最环保和最有效的工具之一,用于将生物质转化为化学品和燃料。纤维素酶是由β-葡萄糖苷酶(BGL)组成的复合酶,内切β-1,4-葡聚糖酶(EG),和外型β-1,4-葡聚糖酶(CBH),协同地将纤维素水解成单糖。BGL,进一步将EG和CBH催化得到的纤维二糖和短链纤维寡糖解构成葡萄糖,是由这三种酶构成的协同酶系统中最敏感的成分,极易受到外界条件的灭活,成为生物质转化中的限速成分。本文首先介绍了生物质资源利用过程中BGL的来源和催化机理。重点是审查水解过程中影响BGL活性的各种因素,包括木质素的竞争性吸附,气液界面失活,热失活,和溶剂效应。并从底物起始和酶起始两个方面提出了改善BGL失活的方法。特别是,筛选,修改,重点讨论了酶分子本身的改变。本综述可为BGL失活机制的研究提供新的思路。遏制失活,和活动增强。关键点:•描述了影响β-葡糖苷酶失活的因素。•过程强化以底物和酶的形式呈现。•溶剂选择,蛋白质工程,和固定仍然是感兴趣的话题。
Lignocellulosic biomass has emerged as a promising environmental resource. Enzyme catalysis, as one of the most environmentally friendly and efficient tools among various treatments, is used for the conversion of biomass into chemicals and fuels. Cellulase is a complex enzyme composed of β-glucosidase (BGL), endo-β-1,4-glucanase (EG), and exo-β-1,4-glucanase (CBH), which synergistically hydrolyzes cellulose into monosaccharides. BGL, which further deconstructs cellobiose and short-chain cellooligosaccharides obtained by EG and CBH catalysis into glucose, is the most sensitive component of the synergistic enzyme system constituted by the three enzymes and is highly susceptible to inactivation by external conditions, becoming the rate-limiting component in biomass conversion. This paper firstly introduces the source and catalytic mechanism of BGL used in the process of biomass resource utilization. The focus is on the review of various factors affecting BGL activity during hydrolysis, including competitive adsorption of lignin, gas-liquid interface inactivation, thermal inactivation, and solvent effect. And the methods to improve BGL inactivation are proposed from two aspects-substrate initiation and enzyme initiation. In particular, the screening, modification, and alteration of the enzyme molecules themselves are discussed with emphasis. This review can provide novel ideas for studies of BGL inactivation mechanism, containment of inactivation, and activity enhancement. KEY POINTS: • Factors affecting β-glucosidase inactivation are described. • Process intensification is presented in terms of substrate and enzyme. • Solvent selection, protein engineering, and immobilization remain topics of interest.