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

Abstract

A Gram-stain negative, rod-shaped, non-motile, strictly aerobic bacterium HK-28T was isolated from a mangrove sediment sample in Haikou city, Hainan Province, China. Strain HK-28T 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 C16:0, Summed Feature 8 (C18:1ω7c and/or C18:1ω6c), Summed Feature 3 (C16:1ω7c and/or C16:1ω6c), C17:0, C12:0 3-OH and C17:1ω8c. 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-28T shared 97.1 and 96.7% sequence similarities to the validly named species Gallaecimonas xiamenensis MCCC 1A01354T and Gallaecimonas pentaromativorans MCCC 1A06435T, respectively, and shared lower sequence similarities (< 92.0%) to all other genera. Phylogenetic analysis showed strain HK-28T was clustered with G. pentaromativorans MCCC 1A06435T and G. xiamenensis MCCC 1A01354T. Strain HK-28T showed low DNA–DNA relatedness with G. xiamenensis MCCC 1A01354T (28.3 ± 1.5%) and G. pentaromativorans MCCC 1A06435T (25.2 ± 2.4%). On the basis of phenotypic, chemotaxonomic and genotypic characteristics, strain HK-28T 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-28T (= KCTC 62177T = MCCC 1K03441).