Speluncibacter jeojiensis gen. nov. sp. nov., a novel bacterium of the order Mycobacteriales isolated from a cave and a proposal of Speluncibacteraceae fam. nov.
Int J Syst Evol Microbiol
; 74(2)2024 Feb.
Article
in En
| MEDLINE
| ID: mdl-38345846
ABSTRACT
Two Gram-stain-positive, aerobic, non-spore-forming, non-motile, irregular rod-shaped actinobacteria, designated as D2-41T and D3-21, were isolated from soil samples collected in a natural cave in Jeju, Republic of Korea. Both of the isolates were shown to share 100â% 16S rRNA sequence identity. The cell wall contained meso-diaminopimelic acid, arabinose and galactose. The predominant menaquinone was MK-8(H2). The polar lipids contained phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannoside, an unidentified aminolipid, an unidentified aminoglycolipid, an unidentified phospholipid and two unidentified lipids. The predominant fatty acids were C16ââ0 and summed feature 3 (C16ââ1 ω7c and/or iso-C15ââ0 2-OH). Mycolic acids of C30-C38 were present. The 16S rRNA gene trees showed that the organisms occupied a distinct position remotely located from recognized genera within the order Mycobacteriales, albeit with the 16S rRNA gene similarities of 97.0-97.1â% with Rhodococcus olei, Rhodococcus rhodnii and Rhodococcus triatomae. The genome sizes and DNA G+C contents of strains D2-41T and D3-21 were 4.77-4.88 Mbp and 69.8âmol%, respectively. Both of the isolates shared an average nucleotide identity of 99.4â% and digital DNA-DNA hybridization of 95.2â% to each other, revealing that strains D2-41T and D3-21 belonged to the same species. In the core genome-based phylogenomic tree, both of the isolates were found to be closely associated with members of the genus Tomitella. However, strains D2-41T and D3-21 revealed the highest amino acid identity values (mean 66.5â%, range 66.2-67.0â% with the genus Prescottella of the family Nocardiaceae, followed by the genus Tomitella (mean 64.1â%, range 63.6-64.7â%) of the family Tomitellaceae. Based on the combined data obtained here, the novel isolates belong to a new genus of the new family for which the name Speluncibacter jeojiensis gen. nov. sp. nov. is proposed, with Speluncibacteraceae fam. nov. The type strain is strain D2-41T (=KACC 17930T=DSM 101875T).
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Actinomycetales
/
Fatty Acids
Language:
En
Journal:
Int J Syst Evol Microbiol
Journal subject:
MICROBIOLOGIA
Year:
2024
Document type:
Article
Country of publication:
United kingdom