Toshchakov Stepan V, Lebedinsky Alexander V, Sokolova Tatyana G, Zavarzina Daria G, Korzhenkov Alexei A, Teplyuk Alina V, Chistyakova Natalia I, Rusakov Vyacheslav S, Bonch-Osmolovskaya Elizaveta A, Kublanov Ilya V, Gavrilov Sergey N
Laboratory of Microbial Genomics, Immanuel Kant Baltic Federal University, Kaliningrad, Russia.
Winogradsky Institute of Microbiology, FRC Biotechnology, Russian Academy of Sciences, Moscow, Russia.
Front Microbiol. 2018 Aug 3;9:1759. doi: 10.3389/fmicb.2018.01759. eCollection 2018.
The genus forms a deeply branching family in the class and is currently represented by three physiologically diverse species of thermophilic prokaryotes. The type strain of the type species, 41, is an obligate chemolithoautotroph growing exclusively by hydrogenogenic CO oxidation. Another strain, isolated from a hot spring at Uzon caldera, Kamchatka in the course of this work, is capable of coupling carboxydotrophy and dissimilatory reduction of Fe(III) from oxic and phyllosilicate minerals. The processes of carboxydotrophy and Fe(III) reduction appeared to be interdependent in this strain. The genomes of both isolates were sequenced, assembled into single chromosome sequences (for strain 41 a plasmid sequence was also assembled) and analyzed. Genome analysis revealed that each of the two strains possessed six genes encoding diverse Ni,Fe-containing CO dehydrogenases (maximum reported in complete prokaryotic genomes), indicating crucial role of carbon monoxide in metabolism. Both strains possessed a set of 30 multiheme -type cytochromes, but only the newly isolated Fe-reducing strain 019 had one extra gene of a 17-heme cytochrome, which is proposed to represent a novel determinant of dissimilatory iron reduction in prokaryotes. Mössbauer studies revealed that strain 019 induced reductive transformation of the abundant ferric/ferrous-mica mineral glauconite to siderite during carboxydotrophic growth. Reconstruction of the strains energy metabolism is the first comprehensive genome analysis of a representative of the deep phylogenetic branch Clostridia Incertae Sedis, family V. Our data provide insights into energy metabolism of with an emphasis on its ecological implications.
该属在 纲中形成一个深度分支的家族，目前由三种生理特性不同的嗜热原核生物物种代表。模式物种的模式菌株 41 是一种专性化能无机自养生物，仅通过产氢的 CO 氧化生长。在这项工作过程中，从堪察加半岛乌宗火山口的温泉中分离出的另一种菌株能够将羧基营养作用与从有氧和层状硅酸盐矿物中异化还原 Fe(III) 的过程偶联起来。在该菌株中，羧基营养作用和 Fe(III) 还原过程似乎相互依存。对这两种分离株的基因组进行了测序、组装成单条染色体序列（对于菌株 41 还组装了一个质粒序列）并进行了分析。基因组分析表明，这两种菌株中的每一种都拥有六个编码不同的含 Ni、Fe 的 CO 脱氢酶的基因（在完整的原核生物基因组中报道的最多），表明一氧化碳在 代谢中起关键作用。两种菌株都拥有一组 30 种多血红素 - 型细胞色素，但只有新分离的铁还原菌株 019 有一个额外的 17 - 血红素细胞色素基因，该基因被认为代表了原核生物中异化铁还原的一个新决定因素。穆斯堡尔研究表明，菌株 019 在羧基营养生长过程中诱导了丰富的铁/亚铁云母矿物海绿石向菱铁矿的还原转化。对 菌株能量代谢的重建是对深系统发育分支 Clostridia Incertae Sedis 家族 V 的一个代表进行的首次全面基因组分析。我们的数据提供了对 能量代谢的见解，并强调了其生态意义。
