Fuente: Microorganisms - Revista científica (MDPI) Microorganisms, Vol. 14, Pages 125: Genomic Insights into Marinovum sedimenti sp. nov., Isolated from Okhotsk Sea Bottom Sediments, Suggest Plasmid-Mediated Strain-Specific Motility
Microorganisms doi: 10.3390/microorganisms14010125
Authors:
Lyudmila Romanenko
Viacheslav Eremeev
Evgeniya Bystritskaya
Peter Velansky
Valeriya Kurilenko
Marina Isaeva

Two Gram-negative aerobic halophilic bacteria, designated KMM 9989T and KMM 9879, were isolated from a bottom sediment sample of the Okhotsk Sea, Russia. The novel strains grew in 0.5–4% NaCl, at 5–35 °C and pH 5.5–10.0. Phylogenetic analyses based on 16S rRNA gene and whole genome sequences placed strains KMM 9989T and KMM 9879 within the family Roseobacteraceae, where they were clustered with their closest relative Marinovum algicola KCTC 22095T. The average nucleotide identity (ANI) between strain KMM 9989T and Marinovum algicola KCTC 22095T was 81.4%. The level of digital DNA–DNA hybridization (dDDH) between the novel isolates KMM 9989T and KMM 9879 was 97%, while between strain KMM 9989T and Marinovum algicola KCTC 22095T, it was 27%. Strains KMM 9989T and KMM 9879 contained Q-10 as the predominant ubiquinone and C18:1ω7c as the major fatty acid. The polar lipids were phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine, diphosphatidylglycerol, an unidentified aminolipid, two unidentified phospholipids, and three unidentified lipids. The genomic size of strains KMM 9989T and KMM 9879 was determined to be 4,040,543 bp and 3,969,839 bp with a DNA GC content of 61.3 and 61.4 mol%, respectively. Both strains contained a common plasmid of 238,277 bp and a strain-specific plasmid (188,734 bp for KMM 9989T and 118,029 bp for KMM 9879). It is suggested that the motility of KMM 9879 may be mediated by the presence of a complete fla2-type operon in the strain-specific chromid. Thus, based on the phylogenetic analyses and distinctive phenotypic characteristics, the novel marine strains KMM 9989T and KMM 9879 are proposed to be classified as a novel species Marinovum sedimenti sp. nov. with the strain KMM 9989T (=KCTC 8835T) as the type strain of the species.