Gallaecimonas mangrovi sp. nov., a novel bacterium isolated from mangrove sediment

Abstract

A Gram-stain negative, rod-shaped, non-motile, strictly aerobic bacterium HK-28^T was isolated from a mangrove sediment sample in Haikou city, Hainan Province, China. Strain HK-28^T was able to grow at 10-45 °C (optimum 25-30 °C), pH 5.0-8.5 (optimum 6.0-7.0) and 0.5-12.0% (w/v) NaCl (optimum 1.0-3.0%, w/v). The major cellular fatty acids were C_16:0, Summed Feature 8 (C_18:1 ω7c and/or C_18:1 ω6c), Summed Feature 3 (C_16:1 ω7c and/or C_16:1 ω6c), C_17:0, C_12:0 3-OH and C_17:1ω8c. Ubiquinone-8 (Q-8) was the predominant respiratory quinone. The polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, two unidentified aminophospholipids, four unidentified phospholipids, two unidentified glycolipid, an unidentified glycophospholipid, an unidentified aminolipid and an unidentified lipid. The DNA G+C content was 50.2 mol%. Accoroding to 16S rRNA gene sequence similarities, strain HK-28^T shared 97.1 and 96.7% sequence similarities to the validly named species Gallaecimonas xiamenensis MCCC 1A01354^T and Gallaecimonas pentaromativorans MCCC 1A06435^T, respectively, and shared lower sequence similarities (< 92.0%) to all other genera. Phylogenetic analysis showed strain HK-28^T was clustered with G. pentaromativorans MCCC 1A06435^T and G. xiamenensis MCCC 1A01354^T. Strain HK-28^T showed low DNA-DNA relatedness with G. xiamenensis MCCC 1A01354^T (28.3 ± 1.5%) and G. pentaromativorans MCCC 1A06435^T (25.2 ± 2.4%). On the basis of phenotypic, chemotaxonomic and genotypic characteristics, strain HK-28^T is considered to represent a novel species in the genus Gallaecimonas, for which the name Gallaecimonas mangrovi sp. nov. is proposed. The type strain is HK-28^T (= KCTC 62177^T = MCCC 1K03441).

Keywords: Gallaecimonas mangrovi; Mangrove sediment; Taxonomy.