ABSTRACT
A halotolerant, psychrotolerant and methylotrophic methanogen, strain SY-01T, was isolated from the saline Lake Tus in Siberia. Cells of strain SY-01T were non-motile, cocci and 0.8-1.0 µm in diameter. The only methanogenic substrate utilized by strain SY-01T was methanol. The temperature range of growth for strain SY-01T was from 4 to 40 °C and the optimal temperature for growth was 30 °C. The pH range of growth was from pH 7.2 to 9.0, with optimal growth at pH 8.0. The NaCl range of growth was 0-1.55 M with optimal growth at 0.51 M NaCl. The G+C content of the genome of strain SY-01T was 43.6 molâ% as determined by genome sequencing. Phylogenetic analysis revealed that strain SY-01T was most closely related to Methanolobus zinderi SD1T (97.3â% 16S rRNA gene sequence similarity), and had 95.5-97.2â% similarities to other Methanolobus species with valid names. Genome relatedness between strain SY-01T and DSM 21339T was computed using average nucleotide identity and digital DNA-DNAhybridization, which yielded values of 79.7 and 21.7â%, respectively. Based on morphological, phenotypic, phylogenetic and genomic relatedness data presented here, it is evident that strain SY-01T represents a novel species of the genus Methanolobus, and the name Methanolobus halotolerans sp. nov. is proposed. The type strain is SY-01T (=BCRC AR10051T=NBRC 113166 T=DSM 107642T).
Subject(s)
Lakes/microbiology , Methanosarcinaceae/classification , Phylogeny , Saline Waters , Base Composition , DNA, Archaeal/genetics , Methane , Methanosarcinaceae/isolation & purification , Nucleic Acid Hybridization , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA , SiberiaABSTRACT
A psychrotolerant, methylotrophic methanogen, strain YSF-03T, was isolated from the saline meromictic Lake Shira in Siberia. Cells of strain YSF-03T were non-motile, irregular cocci and 0.8-1.2 µm in diameter. The methanogenic substrates utilized by strain YSF-03T were methanol and trimethylamine. The temperature range of growth for strain YSF-03T was from 0 to 37 °C. The optimum growth conditions were 30-37 °C, pH 7.0-7.4 and 0.17 M NaCl. The G+C content of the genome of strain YSF-03T was 41.3 mol%. Phylogenetic analysis revealed that strain YSF-03T was most closely related to Methanolobus profundi MobMT (98.15â% similarity in 16S rRNA gene sequence). Genome relatedness between strain YSF-03T and MobMT was computed using the Genome-to-Genome Distance Calculator and average nucleotide identity, which gave values of 23.5 and 79.3â%, respectively. Based on the morphological, phenotypic, phylogenetic and genomic relatedness data presented here, it is evident that strain YSF-03T represents a novel species of the genus Methanolobus, for which the name Methanolobus psychrotolerans sp. nov. is proposed. The type strain is YSF-03T (=BCRC AR10049T=DSM 104044T=NBRC 112514T).
