Microbulbifer magnicolonia sp. nov., isolated from sediment of tidal flat located in Zhoushan, China

A Gram-stain-negative, aerobic, motile with flagella and rod- or ovoid-shaped bacterium, designated GG15 , was isolated from tidal flat sediment sampled in Zhoushan, Zhejiang Province. Strain GG15 grew at 20-40 °C (optimum, 30 °C), at pH 5.5-9.5 (optimum, pH 7.0-8.0) and with 1.0-10.0 % (w/v) NaCl (optimum, 1.5 %). Colony diameters ranged from 1 to 3 mm within the first week, reaching a maximum of 6-7 mm after 15 days of cultivation. Strain GG15 exhibited highest 16S rRNA gene sequence similarity to CCM 7856 (98.1 %), with similarity to other species within the genus ranging from 97.8 to 93.8 %. Similarity values to other genera were below 93.8 %. Strain GG15 exhibited positive activity for -glucosidase, trypsin and chymotrypsin, whereas the reference strain showed negative activity. Chemotaxonomic analyses indicated that strain GG15 contained Q-8 as the sole respiratory quinone, C (9.1 %), iso-C (30.9 %) and iso-C 3-OH (7.2 %) as the predominant fatty acids, and phosphatidylethanolamine, phosphatidylglycerol, three unidentified lipids, four unidentified glycolipids, one unidentified phospholipid, two unidentified aminolipids and two unidentified aminophospholipids as the main polar lipids. The genome of strain GG15 was 4 307 641 bp long, comprising 3861 protein-coding genes. The G+C content of strain GG15 was 61.5 mol% based on its genomic sequence. Strain GG15 showed low digital DNA-DNA hybridization (