Abstract The lignocellulose hydrolysate-derived inhibitors compromise the cell growth and fermentation. In this study, intracellular redox potential was manipulated by overexpressing eight genes encoding cofactors-related oxidoreductases to improve the tolerance of Zymomonas mobilis ZM4 against lignocellulose hydrolysate-derived inhibitors. Besides, the underlying mechanism was elucidated through monitoring the cellular redox balance including NAD(P)H/NAD(P)+, ROS, and ATP. The oxidoreductases either directly degraded furfural or provided NAD(P)H for reducing it under furfural stress. Whereas, the elevated ratio of NADPH/NADP+ strengthened the tolerance against acetate via removing ROS and supplying ATP. The enzymes benefiting ATP accumulation also enhanced cell growth under formate stress. It is concluded that concentration of inhibitors and metabolic burden both contribute to affect stress tolerance of Z. mobilis. The data here projected a comprehensive approach to developing multi-stress tolerance strategy in industrially valuable strains to produce biofuels and biochemicals from lignocellulosic biomass.

中文翻译：

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运动发酵单胞菌的细胞内氧化还原操作以提高对木质纤维素水解物衍生应激的耐受性

摘要 木质纤维素水解物衍生的抑制剂会影响细胞的生长和发酵。在这项研究中，通过过表达编码辅因子相关氧化还原酶的 8 个基因来操纵细胞内氧化还原电位，以提高运动发酵单胞菌 ZM4 对木质纤维素水解物衍生抑制剂的耐受性。此外，通过监测包括 NAD(P)H/NAD(P)+、ROS 和 ATP 在内的细胞氧化还原平衡，阐明了其潜在机制。氧化还原酶要么直接降解糠醛，要么提供 NAD(P)H 以在糠醛胁迫下将其还原。而升高的 NADPH/NADP+ 比率通过去除 ROS 和提供 ATP 增强了对乙酸盐的耐受性。有利于 ATP 积累的酶还促进了甲酸胁迫下的细胞生长。结论是抑制剂的浓度和代谢负担都有助于影响运动发酵单胞菌的胁迫耐受性。这里的数据预测了一种综合方法，可以在具有工业价值的菌株中开发多应力耐受策略，以从木质纤维素生物质中生产生物燃料和生物化学品。