Gallaecimonas zhanjiangensis sp. nov., a novel member of the phylum Pseudomonadota isolated from mangrove sediments

A bacterial strain, designated RL-SH01 T , was isolated from mangrove sediments in Zhanjiang, Guangdong Province, China. Strain RL-SH01 T is a Gram-negative, rod-shaped and flagellated bacterium. It can grow at 15–35 °C (optimum, 25–35 °C), at pH 4–10 (optimum, pH 5.0–9.0) and with salinities of 0–8% ( w/v ) (optimum, 0.5–5.0%). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain RL-SH01 T belongs to the genus Gallaecimonas . Genome-wide digital DNA–DNA hybridization (dDDH) analysis showed that the dDDH values between strain RL-SH01 T and the other type strains of genus Gallaecimonas were below the 70% species delineation threshold. The major fatty acids were C 16 : 0 , Summed Feature 3 (C 16 : 1 ω6 c and/or C 16 : 1 ω7 c), C 12 : 0 3-OH, Summed Feature 8 (C 18 : 1 ω7 c and/or C 18 : 1 ω6 c), C 17 : 1 ω8 c, C 17 : 0 and C 12 : 0 . The major respiratory quinone was Q8 (97.8%). Polar lipids included aminophospholipid, phosphatidylethanolamine, phosphatidylglycerol, phospholipid and an unidentified lipid. The DNA G+C content of strain RL-SH01 T was 58.50 mol%. Based on morphological, physiological, chemotaxonomic and genomic evidence, strain RL-SH01 T represents a novel species of the genus Gallaecimonas , for which the name Gallaecimonas zhanjiangensis sp. nov. is proposed. The type strain is RL-SH01 T (=MCCC 1K10613 T =KCTC 18644 T ). In general, the discovery of this new species enriches the germplasm resources of the genus Gallaecimonas , and broadens our understanding of its phylogenetic diversity and ecological distribution.