Sulfuricystis multivorans gen. nov., sp. nov. and Sulfuricystis thermophila sp. nov., facultatively autotropic sulfur-oxidizing bacteria isolated from a hot spring, and emended description of the genus Rugosibacter

Abstract

Strains J5B T and M52 T are facultatively autotrophic sulfur-oxidizing bacterium isolated from a microbial mat from a hot spring. They were isolated and partially characterized in previous studies, as facultative anaerobes which use nitrate as electron acceptor. In this study, additional characterizations were made to determine their taxonomic status. In both strains, major cellular fatty acids were C 16:1 (C 16:1 ω7c and/or C 16:1 ω6c) and C 16:0 . Their chemotihoautorophic growth was supported by thiosulfate and elemental sulfur. They used some organic acids as growth substrates. Their 16S rRNA gene sequences indicated the highest sequence identities to species in the family Sterolibacteriaceae, but the identities were 95% or lower. Values of average nucleotide identity and digital DNA-DNA hybridization between strains J5B T and M52 T were 87.93% and 34.3%, respectively. Phylogenetic analysis of the 16S rRNA gene sequences indicated that these strains belong to the family Sterolibacteriaceae but not to any existing genera. On the basis of phenotypic and genomic characteristics, Sulfuricystis multivorans gen. nov. sp. nov., and Sulfuricystis thermophila sp. nov. are proposed, with type strains of J5B T (= BCRC 81386 T = DSM 104688 T = NBRC 112605 T ) and M52 T (= BCRC 81387 T = NBRC 114016 T ), respectively. An emended description of the genus Rugosibacter is also proposed, for its reclassi cation to the family Sterolibacteriaceae.

Metabolic adaptations and aquifer connectivity underpin the high productivity rates in the relict subsurface water

“…Halothiobacillus neapolitanus, a sulfur-oxidizing chemolithoautotrophic bacterium in which carboxysomes were studied in detail [50,51]. The southmost Shizafon site (wells C1 and S1) stood out, as the sulfur-oxidizing Rhodocyclaceae UBA2250 sp004323595 lineage (Burkholderiales, corresponds to the GCA_004323595.1 NCBI submission, identified previously as Sulfuricystis, [52]) was predominant in both carbonate and sandstone aquifers. Moreover, the ammonia-oxidizing Nitrosotenuis was prominent in S1 (circa 6% read abundance).…”