Limnobacter parvuscolonica sp. nov., thiosulfate-oxidizing bacterium isolated from lake water

Abstract

A novel bacterium, strain YS8-69T, was isolated from an inland closed lake, Xinjiang province, PR China. Comparative analysis of the 16S rRNA gene sequence shows the strain is affiliated to the genus Limnobacter, in the family Burkholderiaceae, with the highest similarities to Limnobacter alexandrii LZ-4T (98.93%), Limnobacter thiooxidans DSM 13612T (98.55%), Limnobacter humi NBRC 111650T (97.66%), and Limnobacter litoralis KP1-19T (97.04%). Strain YS8-69T was a Gram-stain-negative, rod-shaped, catalase- and oxidase-positive bacterium, and growth was observed at 4–40°C (optimum, 25°C), pH 7.0–10.0 (optimum, pH 7.0) and 0–3% (w/v) NaCl (optimum, 0.5%). It grew chemolithoautotrophically using thiosulfate. The principal fatty acids were C16:0, summed feature 3 (C16:1 ω7c and/or C16:1 ω6c), and summed feature 8 (C18:1 ω7c and/or C18:1 ω6c). The major respiratory quinone was Q-8 and predominant polar lipids were diphosphatidylglycerol (DPG), phosphatidylglycerol (PG), phosphatidylethanolamine (PE), two unidentified aminolipids (AL1,2), two unidentified glycolipids (GL1,2), an unidentified amino phosphoglycolipid (APGL), two unidentifed phospholipid (PL1,2), and two unidentified lipids (L1,2). The average nucleotide identity (ANI) values between strain YS8-69T and L. thiooxidans JCM 13612T, L. humi DSM 111650T were 36% and 15.80% respectively. The final genome sequencing showed that length of strain YS8-69T genome was 3,162,663 bp, with 20 contigs, and 51.7 mol % of G + C content. Based on physiological, chemotaxonomic, genotypic characteristics, and phylogenetic results in the polyphasic taxonomy approach, we propose that strain YS8-69T represents a novel specie of the genus Limnobacter, for which the name Limnobacter parvuscolonica sp. nov. is proposed (type strain YS8-69T = MCCC 1K08015T = KCTC 92278T).