Open AccessSphaerochaeta halotolerans sp. nov., a novel spherical halotolerant spirochete from a Russian heavy oil reservoir, emended description of the genus Sphaerochaeta, reclassification of Sphaerochaeta coccoides to a new genus Parasphaerochaeta gen. nov. as Parasphaerochaeta coccoides comb. nov. and proposal of Sphaerochaetaceae fam. nov.
Author(s) -
Salimat K. Bidzhieva,
Diyana S. Sokolova,
Denis S. Grouzdev,
N. A. Kostrikina,
А. Б. Полтараус,
T. P. Tourova,
V. A. Shcherbakova,
Olga Troshina,
Т. Н. Назина
Publication year - 2020
Publication title -
international journal of systematic and evolutionary microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.925
H-Index - 173
eISSN - 1466-5034
pISSN - 1466-5026
DOI - 10.1099/ijsem.0.004340
Subject(s) - biology , halotolerance , 16s ribosomal rna , strain (injury) , glycolipid , genomic dna , genus , genome , microbiology and biotechnology , bacteria , phylogenetic tree , peptidoglycan , botany , dna , gene , genetics , biochemistry , anatomy
Anaerobic, fermentative, halotolerant bacteria, strains 4-11 T and 585, were isolated from production water of two low-temperature petroleum reservoirs (Russia) and were characterized by using a polyphasic approach. Cells of the strains were spherical, non-motile and 0.30–2.5 µm in diameter. Strain 4-11 T grew optimally at 35 °C, pH 6.0 and 1.0–2.0% (w/v) NaCl. Both strains grew chemoorganotrophically with mono-, di- and trisaccharides. The major cellular fatty acids of both strains were C 14:0 , C 16:0 , C 16:1 ω9 and C 18:0 3-OH. Major polar lipids were glycolipids and phospholipids. The 16S rRNA gene sequences of the strains 4-11 T and 585 had 99.9% similarity and were most closely related to the sequence of Sphaerochaeta associata GLS2 T (96.9, and 97.0% similarity, respectively). The G+C content of the genomic DNA of strains 4-11 T and 585 were 46.8 and 46.9%, respectively. The average nucleotide identity and digital DNA–DNA hybridization values between the genomes of strain 4-11 T and S. associata GLS2 T were 73.0 and 16.9%, respectively. Results of phylogenomic metrics analysis of the genomes and 120 core proteins of strains 4-11 T and 585 and their physiological and biochemical characteristics confirmed that the strains represented a novel species of the genus Sphaerochaeta , for which the name Sphaerochaeta halotolerans sp. nov. is proposed, with the type strain 4-11 T (=VKM B-3269 T =KCTC 15833 T ). Based on the results of phylogenetic analysis, Sphaerochaeta coccoides was reclassified as member of a new genus Parasphaerochaeta gen. nov., Parasphaerochaeta coccoides comb. nov. The genera Sphaerochaeta and Parasphaerochaeta form a separate clade, for which a novel family, Sphaerochaetaceae fam. nov., is proposed.