Cao Lian-Ying, Liu Chen-Guang, Yang Shi-Hui, Bai Feng-Wu
State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Science, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China.
State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, China.
Front Bioeng Biotechnol. 2023 Feb 8;11:1130405. doi: 10.3389/fbioe.2023.1130405. eCollection 2023.
is a potential alternative of to produce cellulosic ethanol with strengths in cofactor balance, but its lower tolerance to inhibitors in the lignocellulosic hydrolysate restricts the application. Although biofilm can improve bacteria stress tolerance, regulating biofilm formation in is still a challenge. In this work, we constructed a pathway by heterologous expressing and from in s to produce AI-2 (autoinducer 2), a universal quorum-sensing signal molecule, to control cell morphology for enhancing stress tolerance. Unexpectedly, the results suggested that neither endogenous AI-2 nor exogenous AI-2 promoted biofilm formation, while heterologous expression of can significantly raise biofilm. Therefore, we proposed that the main factor in assisting biofilm formation was the product accumulated due to heterologous expression of , like methylated DNA. Consequently, ZM4::pfs produced more biofilm, which presented an enhanced tolerance to acetic acid. All these findings provide a novel strategy to improve the stress tolerance of by enhancing biofilm formation for efficient production of lignocellulosic ethanol and other value-added chemical products.
是一种在辅因子平衡方面具有优势的生产纤维素乙醇的潜在替代方法，但其对木质纤维素水解产物中抑制剂的耐受性较低限制了其应用。尽管生物膜可以提高细菌的胁迫耐受性，但在中调节生物膜形成仍然是一个挑战。在这项工作中，我们通过在中异源表达来自的和来构建一条途径，以产生AI-2（自诱导物2），一种通用的群体感应信号分子，来控制细胞形态以增强胁迫耐受性。出乎意料的是，结果表明内源性AI-2和外源性AI-2均未促进生物膜形成，而异源表达可以显著提高生物膜形成。因此，我们提出辅助生物膜形成的主要因素是由于的异源表达而积累的产物，如甲基化DNA。因此，ZM4::pfs产生了更多的生物膜，对乙酸表现出增强的耐受性。所有这些发现为通过增强生物膜形成来提高的胁迫耐受性以高效生产木质纤维素乙醇和其他增值化学产品提供了一种新策略。
