Reysenbachia aerophila gen. nov., sp. nov., a facultatively anaerobic, hydrogen-oxidizing, thermophilic bacterium isolated from Kuirau Park, Rotorua, New Zealand

Abstract

A facultatively anaerobic, hydrogen-oxidizing, thermophilic bacterium (strain KUI-RBT) was isolated from a geothermal spring biofilm in Rotorua, New Zealand. Strain KUI-RBT is a motile, straight rod, measuring approximately 0.7 {micro}m by 1.0 to 1.5 {micro}m with a diderm cell wall. Growth of KUI-RBT occurred from 39 to 74 {degrees}C (Topt 64.5 {degrees}C), pH 5.0 to 7.5 (pHopt 6.5), and 0 to 1% (w/v) NaCl (NaClopt 0.4-0.7%, w/v). KUI-RBT utilizes carbon dioxide and various organic carbon substrates as carbon sources and hydrogen as an electron donor. KUI-RBT can use oxygen (0-21%, v/v), elemental sulfur, thiosulfate, sulfite, nitrate, arsenate, and selenate as terminal electron acceptors. Major fatty acids of strain KUI-RBT include C20:1, C18:1, and C18:0 and the primary quinone is MTK-7. The whole genome G+C content is 34.23 mol%. Phylogenetic analyses indicate KUI-RBT to be a member of the family Hydrogenothermaceae, with Sulfurihydrogenibium azorense Az-Fu1T its closest characterised relative (94.51% 16S rRNA gene sequence similarity, 78.01% whole genome ANI, 61.34% whole genome AAI). Based on phylogenetic and phenotypic analyses, we propose KUI-RBT represents a novel genus and species within the family Hydrogenothermaceae, for which we propose the name Reysenbachia aerophila gen. nov., sp. nov. The type strain is KUI-RBT (=KCTC accession =JCM accession). The GenBank accession number for the 16S rRNA gene sequence of strain KUI-RBT is PZ052650. The GenBank accession number for the whole genome of strain KUI-RBT is JBVODP000000000.