Wang Jian, Yang Jian, Shi Guoxin, Li Weidong, Ju Yun, Wei Liang, Liu Jun, Xu Ning
College of Biological and Agricultural Engineering, Jilin University, Changchun, China.
School of Food Engineering and Biotechnology, Tianjin University of Science and Technology, Tianjin, China.
Front Bioeng Biotechnol. 2022 Aug 9;10:933325. doi: 10.3389/fbioe.2022.933325. eCollection 2022.
has been widely and effectively used for fermentative production of l-lysine on an industrial scale. However, high-level accumulation of end products inevitably leads to osmotic stress and hinders further increase of l-lysine production. At present, the underlying mechanism by which cells adapt to high-lysine-induced osmotic stress is still unclear. In this study, we conducted a comparative transcriptomic analysis by RNA-seq to determine gene expression profiles under different high-lysine stress conditions. The results indicated that the increased expression of some metabolic pathways such as sulfur metabolism and specific amino acid biosynthesis might offer favorable benefits for high-lysine adaptation. Functional assays of 18 representative differentially expressed genes showed that the enhanced expression of multiple candidate genes, especially chaperon, conferred high-lysine stress tolerance in . Moreover, DNA repair component MutT and energy-transducing NADH dehydrogenase Ndh were also found to be important for protecting cells against high-lysine-induced osmotic stress. Taken together, these aforementioned findings provide broader views of transcriptome profiles and promising candidate targets of for the adaptation of high-lysine stress during fermentation.
已被广泛且有效地用于工业规模发酵生产L-赖氨酸。然而，终产物的高水平积累不可避免地导致渗透胁迫，并阻碍L-赖氨酸产量的进一步提高。目前，细胞适应高赖氨酸诱导的渗透胁迫的潜在机制仍不清楚。在本研究中，我们通过RNA测序进行了比较转录组分析，以确定不同高赖氨酸胁迫条件下的基因表达谱。结果表明，一些代谢途径如硫代谢和特定氨基酸生物合成的表达增加可能为高赖氨酸适应提供有利条件。对18个代表性差异表达基因的功能分析表明，多个候选基因的增强表达，尤其是伴侣蛋白，赋予了对高赖氨酸胁迫的耐受性。此外，还发现DNA修复成分MutT和能量转换型NADH脱氢酶Ndh对于保护细胞免受高赖氨酸诱导的渗透胁迫也很重要。综上所述，这些发现为转录组图谱提供了更广泛的视角，并为发酵过程中高赖氨酸胁迫适应提供了有前景的候选靶点。
