The classical route for second‐generation ethanol from lignocellulosic biomass is hampered by high process costs, fostering the development of alternative strategies such as simultaneous saccharification and fermentation (SSF). However, the lack of compatible enzyme cocktails poses a challenge. In this study, the enzyme EmBgl from the marine bacterium Exiguobacterium marinum was rationally identified based on structural and phylogenetic analyses, known desirable properties of close orthologs, and the ecological niche of its organism source. EmBgl is a multifunctional and glucose‐tolerant enzyme that efficiently hydrolyzes cello‐oligosaccharides due to a positive‐subsite region that can accommodate long cello‐oligosaccharides without imposing steric impediments. The efficacy of EmBgl in an SSF process was demonstrated using pretreated sugarcane bagasse as feedstock, yielding 28 g L⁻¹ of ethanol in 30 h. The distinguishing functional properties of EmBgl and its successful utilization in an SSF process highlight its potential in biotechnological applications in which lignocellulose deconstruction is desirable under milder temperatures © 2020 Society of Chemical Industry and John Wiley & Sons, Ltd.

中文翻译：

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合理鉴定的海洋GH1β-葡萄糖苷酶具有同时糖化和发酵的独特功能

木质纤维素生物质生产第二代乙醇的经典途径因加工成本高而受阻，从而促进了替代策略的发展，例如同时糖化和发酵（SSF）。然而，缺乏相容的酶混合物构成了挑战。在这项研究中，基于结构和系统发育分析，已知直系同源物的理想特性以及其生物来源的生态位，合理地鉴定了来自海洋细菌海藻Exiguobacterium的酶Em Bgl 。EMBgl是一种多功能且耐葡萄糖的酶，由于其阳性亚位区域可容纳长纤维寡糖而不会造成空间障碍，因此可以有效地水解纤维寡糖。使用预处理的甘蔗渣作为原料证明了Em Bgl在SSF工艺中的功效，在30小时内产生28 g L ^-1的乙醇。Em Bgl的独特功能特性及其在SSF工艺中的成功利用突显了其在生物技术应用中的潜力，在这种技术中，木质纤维素的分解在较温和的温度下是可取的。©2020年化学工业协会和John Wiley＆Sons，Ltd.