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Marinobacter profundi sp. nov., a slightly halophilic bacterium isolated from a deep-sea sediment sample of the New Britain Trench

Cao, Junwei, Liu, Ping, Liu, Renju, Su, Hainan, Wei, Yuli, Liu, Rulong, Fang, Jiasong
Antonie van Leeuwenhoek 2019 v.112 no.3 pp. 425-434
DNA, Marinobacter, bacteria, chemotaxonomy, enzymes, essential genes, fatty acids, marine sediments, multilocus sequence typing, new species, pH, phenotype, phosphatidylethanolamines, quinones, ribosomal RNA, sodium chloride
A piezotolerant, cold-adapted, slightly halophilic bacterium, designated strain PWS21ᵀ, was isolated from a deep-sea sediment sample collected from the New Britain Trench. Cells were observed to be Gram-stain negative, rod-shaped, oxidase- and catalase-positive. Growth of the strain was observed at 4–45 °C (optimum 37 °C), at pH 5.0–9.0 (optimum 7.0) and in 0.5–20% (w/v) NaCl (optimum 3–4%). The optimum pressure for growth was 0.1 MPa (megapascal) with tolerance up to 70 MPa. 16S rRNA gene sequence analysis showed that strain PWS21ᵀ is closely related to Marinobacter guineae M3Bᵀ (98.4%) and Marinobacter lipolyticus SM19ᵀ (98.2%). Multilocus sequence analysis (MLSA) based on sequences of housekeeping genes gyrB, recA, atpD, rpoB and rpoD indicates that strain PWS21ᵀ represents a distinct evolutionary lineage within the genus Marinobacter. Furthermore, strain PWS21ᵀ showed low ANI and diDDH values to the closely related species. The principal fatty acids were identified as C₁₂:₀, C₁₂:₀ 3-OH, C₁₆:₁ω9c, C₁₆:₀ and C₁₈:₁ω9c. Ubiquinone-9 was identified as the major respiratory quinone. The polar lipids were identified as phosphatidylethanolamine (PE), phosphatidylglycerol (PG), diphosphatidylglycerol (DPG), aminophospholipid (APL), two unidentified lipids and an unidentified phospholipid (PL). The G + C content of the genomic DNA was determined to be 60.3 mol%. On the basis of phenotypic, chemotaxonomic and molecular data, we conclude that strain PWS21ᵀ represents a novel species of the genus Marinobacter, for which the name Marinobacter profundi sp. nov. is proposed (type strain PWS21ᵀ = KCTC 52990ᵀ = MCCC 1K03345ᵀ).