Zhang Guoxiu, Liu Pei, Zhang Lei, Wei Wei, Wang Xuedong, Wei Dongzhi, Wang Wei
State key Lab of Bioreactor Engineering, New World Institute of Biotechnology, East China University of Science and Technology, Shanghai 200237, China.
State key Lab of Bioreactor Engineering, New World Institute of Biotechnology, East China University of Science and Technology, Shanghai 200237, China.
J Biotechnol. 2016 Sep 20;234:35-42. doi: 10.1016/j.jbiotec.2016.07.017. Epub 2016 Jul 25.
Glycoside hydrolases (GHases) of higher performance are immediately needed for efficient degradation of plant biomass into fermentable sugars in industrial processes. The current study represents functional characterization of the enzymatic repertoire involved in crude cotton biomass degradation. Physical contact between cells and substrate is necessary for efficient hydrolysis of cellulose. Cytophagales, which plays a major role in cotton biomass decomposition, was identified as a prevalent community member by 16S rRNA analysis. From the metagenome data, 2058 GHase homologs were identified, of which sixteen were successfully expressed in E. coli. Four enzymes showed activities on p-nitrophenyl-β-d-xylopyranoside, four showed activities on p-nitrophenyl-β-d-glucopyranoside, two had activities against p-nitrophenyl-β-d-glucuronide, one showed activity on laminarin, three had activities against p-nitrophenyl-N-acetyl-β-d-glucosaminide, one had activity towards carboxymethyl cellulose, and one towards p-nitrophenyl-β-d-mannopyranoside. Metagenomics provides a good resource for mining novel biomass degrading enzymes. The sixteen GHases that were cloned may have potential application for biomass conversion and bioproduct production. Functional characterization of the enzymatic repertoire in cotton biomass degradation and analysis of the GHases provide insight into the composition and interaction of enzymes and pathways of plant biomass degradation.
在工业生产过程中，高效地将植物生物质降解为可发酵糖，迫切需要高性能的糖苷水解酶（GHases）。当前的研究描述了参与粗棉生物质降解的酶库的功能特征。细胞与底物之间的物理接触对于纤维素的有效水解是必要的。通过16S rRNA分析，在棉花生物质分解中起主要作用的噬纤维菌目被鉴定为一个普遍存在的群落成员。从宏基因组数据中，鉴定出2058个GHase同源物，其中16个在大肠杆菌中成功表达。四种酶对对硝基苯基-β-D-吡喃木糖苷有活性，四种对对硝基苯基-β-D-吡喃葡萄糖苷有活性，两种对β-D-葡萄糖醛酸苷有活性，一种对海带多糖有活性，三种对N-乙酰-β-D-氨基葡萄糖苷有活性，一种对羧甲基纤维素有活性，一种对β-D-吡喃甘露糖苷有活性。宏基因组学为挖掘新型生物质降解酶提供了良好的资源。克隆的这16种GHases可能在生物质转化和生物产品生产中具有潜在应用。对棉花生物质降解中酶库的功能表征以及对GHases的分析，有助于深入了解植物生物质降解过程中酶和途径的组成及相互作用。
