Maribacter aestuarii sp. nov., isolated from tidal flat sediment, and an emended description of the genus Maribacter

Abstract

A Gram-staining-negative, strictly aerobic bacterial strain, motile by gliding, designated GY20(T), was isolated from a tidal flat at Gwangyang Bay, South Korea. Cells were moderately halophilic, catalase- and oxidase-positive rods. Growth of strain GY20(T) was observed at 10-30 °C (optimum, 25 °C), at pH 6.5-11.0 (optimum, pH 7.0-8.0) and in the presence of 1-5% (w/v) NaCl (optimum, 2-3%). MK-6 was detected as the sole isoprenoid quinone, and iso-C(15:0), iso-C(15:1) G, summed feature 3 (comprising C(16:1)ω7c and/or C(16:1)ω6c), summed feature 9 (iso-C(17:1)ω9c and/or 10-methyl C(16:0)), iso-C(17:0) 3-OH and iso-C(15:0) 3-OH as major fatty acids. Strain GY20(T) contained phosphatidylethanolamine, one unidentified glycolipid and one unidentified lipid as major polar lipids. The G+C content of the genomic DNA was 39.8 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain GY20(T) formed a tight phyletic lineage with members of the genus Maribacter. Strain GY20(T) was most closely related to Maribacter dokdonensis DSW-8(T), with sequence similarity of 96.2%. On the basis of phenotypic, chemotaxonomic and molecular properties, strain GY20(T) was shown to represent a novel species within the genus Maribacter, for which the name Maribacter aestuarii sp. nov. is proposed. The type strain is GY20(T) ( =KACC 16440(T) =JCM 18631(T)). An emended description of the genus Maribacter is also proposed.