Department of Biotechnology, The Catholic University of Korea, Bucheon, Gyeonggi 420-743, South Korea.
Biotechnol Lett. 2013 May;35(5):709-17. doi: 10.1007/s10529-012-1135-9. Epub 2013 Jan 4.
Corynebacterium glutamicum was adapted in a chemostat for 1,900 h with gradually increasing H2O2 stress to understand the oxidative stress response of an industrial host. After 411 generations of adaptation, C. glutamicum developed the ability to grow under stress of 10 mM H2O2, whereas the wild-type did not. The adapted strain also showed increased stress resistance to diamide and menadione, SDS, Tween 20, HCl, NaOH, and ampicillin. A total of 1,180 genes in the RNA-seq transcriptome analysis of the adapted strain were up-regulated twice or higher (corresponding to 38.6 % of the genome), and 126 genes were down-regulated half or less (4.1 % of genome) under 10 mM H2O2-stress conditions compared with those of the wild-type under a no stress condition. Especially the aromatic compound-degrading gene clusters (vanRABK, pcaJIRFLO, and benABCDRKE) were more than threefold up-regulated. Plausible reasons for the H2O2-stress tolerance of the adapted strain are discussed as well as the potential strategy for development of oxidative stress-tolerant strain.
经过 1900 小时的恒化器适应实验，逐步增加 H2O2 胁迫，谷氨酸棒杆菌逐渐适应了氧化应激。经过 411 代的适应，该菌株能够在 10mM H2O2 胁迫下生长，而野生型则不能。适应菌株对二酰胺和甲萘醌、SDS、吐温 20、HCl、NaOH 和氨苄青霉素的应激抗性也有所增加。在适应菌株的 RNA-seq 转录组分析中，共有 1180 个基因的表达水平上调了两倍或更高（相当于基因组的 38.6%），而在 10mM H2O2 胁迫条件下，与野生型在无胁迫条件下相比，有 126 个基因的表达水平下调了一半或更低（基因组的 4.1%）。特别是芳香族化合物降解基因簇（vanRABK、pcaJIRFLO 和 benABCDRKE）的上调幅度超过三倍。本文还讨论了适应菌株对 H2O2 胁迫耐受的可能原因以及开发氧化应激耐受菌株的潜在策略。
