Korea Institute of Ocean Science and Technology, Busan, 49111, Republic of Korea.
Department of Biology, California State University, Fresno, CA, 93740-8034, USA.
J Microbiol. 2019 Feb;57(2):138-142. doi: 10.1007/s12275-019-8592-y. Epub 2019 Jan 31.
Thermococcus onnurineus NA1, an obligate anaerobic hyperthermophilic archaeon, showed variable oxygen (O) sensitivity depending on the types of substrate employed as an energy source. Unexpectedly, the culture with yeast extract as a sole energy source showed enhanced growth by 2-fold in the presence of O. Genome-wide transcriptome analysis revealed the upregulation of several antioxidant-related genes encoding thioredoxin peroxidase (TON_0862), rubrerythrin (TON_0864), rubrerythrin-related protein (TON_0873), NAD(P)H rubredoxin oxidoreductase (TON_0865), or thioredoxin reductase (TON_1603), which can couple the detoxification of reactive oxygen species with the regeneration of NAD(P) from NAD(P)H. We present a plausible mechanism by which O serves to maintain the intracellular redox balance. This study demonstrates an unusual strategy of an obligate anaerobe underlying O-mediated growth enhancement despite not having heme-based or cytochrome-type proteins.
奥氏甲烷球菌 NA1 是一种严格厌氧菌的嗜热古菌，其对氧气的敏感性因所使用的底物类型而异。出乎意料的是，以酵母提取物为唯一能源的培养物在存在氧气的情况下，其生长速度提高了 2 倍。全基因组转录组分析显示，几种与抗氧化相关的基因上调，这些基因编码硫氧还蛋白过氧化物酶（TON_0862）、 rubrerythrin（TON_0864）、rubrerythrin 相关蛋白（TON_0873）、NAD(P)H rubredoxin 氧化还原酶（TON_0865）或硫氧还蛋白还原酶（TON_1603），它们可以将活性氧的解毒与 NAD(P)H 从 NAD(P)的再生偶联起来。我们提出了一种合理的机制，即氧气可以维持细胞内的氧化还原平衡。本研究展示了一种不寻常的策略，即在没有血红素或细胞色素型蛋白的情况下，严格厌氧菌可以通过氧气介导来增强生长。
