Krishna Pilla Sankara, Raghunathan Sarada, Prakash Jogadhenu S S
Department of Biotechnology and Bioinformatics, School of Life Sciences, University of Hyderabad, Hyderabad, Telangana 500046 India.
3 Biotech. 2021 Aug;11(8):392. doi: 10.1007/s13205-021-02938-x. Epub 2021 Jul 31.
is a halo-alkaliphile with optimal growth at pH 10 and 5% NaCl. Phylogenetic analysis revealed habitat-dependent segregation of , with all the alkalihalophiles forming a separate clade. It uses acidification of the external medium and pH-dependent cell wall reinforcement to survive sodic environments. Interestingly, comparative genome analysis revealed the genome encodes surface proteins with a high proportion of acidic amino acids compared to their orthologs of a piece of direct evidence for adaptive evolution. It has a relatively higher number of genes involved in the metabolism of osmolytes and sodium-dependent transporters when compared to Growth of strain Kh10-101 (hereafter ) is Na dependent, with a minimum of 4% NaCl at neutral pH, but 0.5% NaCl is enough at pH 10. It tolerated a sudden increase in salt concentration and exhibited an elongated phenotype but could not tolerate a sudden pH shift from 7 to 11. The cell envelope got damaged, confirming that the pH regulation through cell wall reinforcement is key to survival at a high-pH condition. We report for the first time a comprehensive genome analysis of to delineate the mechanisms evolved for adaptation to halo-alkaline conditions.
The online version contains supplementary material available at 10.1007/s13205-021-02938-x.
是一种嗜盐嗜碱菌，在pH值为10和5%氯化钠的条件下生长最佳。系统发育分析表明，嗜盐嗜碱菌存在依赖于栖息地的分类，所有嗜盐嗜碱菌形成一个单独的进化枝。它利用外部培养基的酸化和pH依赖的细胞壁强化来在高钠环境中生存。有趣的是，比较基因组分析显示，与 的直系同源物相比，该基因组编码的表面蛋白含有较高比例的酸性氨基酸，这是适应性进化的直接证据。与 相比，它在渗透物代谢和钠依赖性转运蛋白方面涉及的基因数量相对较多。Kh10-101菌株（以下简称 ）的生长依赖于钠，在中性pH值下至少需要4%的氯化钠，但在pH值为10时0.5%的氯化钠就足够了。它能耐受盐浓度的突然增加并表现出伸长的表型，但不能耐受pH值从7突然变为11。细胞膜受损，证实通过细胞壁强化进行pH调节是在高pH条件下生存的关键。我们首次报告了对 的全面基因组分析，以阐明其适应盐碱条件所进化出的机制。
在线版本包含可在10.1007/s13205-021-02938-x获取的补充材料。
