Microbulbifer aggregans sp. nov., isolated from estuarine sediment from a mangrove forest.

A novel, rod-shaped, Gram-stain-negative, halophilic and non-motile bacterium, designated CCB-MM1, was isolated from a sample of estuarine sediment collected from Matang Mangrove Forest, Malaysia. The cells possessed a rod-coccus cell cycle in association with growth phase and formed aggregates. Strain CCB-MM1 was both catalase and oxidase positive, and able to degrade starch. Optimum growth occurred at 30 °C and pH 7.0 in the presence of 2-3 % (w/v) NaCl. The 16S rRNA gene sequence of strain CCB-MM1 showed 98.12, 97.46 and 97.33 % sequence similarity with Microbulbifer rhizosphaerae Cs16b, Microbulbifer maritimus TF-17 and Microbulbifergwangyangensis GY2 respectively. Strain CCB-MM1 and M. rhizosphaerae Cs16b formed a cluster in the phylogenetic tree. The major cellular fatty acids were iso-C17 : 1 ω9c and iso-C15 : 0, and the total polar lipid profile consisted of phosphatidylglycerol, phosphatidylethanolamine, phosphoaminolipid, two unidentified lipids, an unidentified glycolipid and an unidentified aminolipid. The major respiratory quinone was ubiquinone Q-8 and the genomic DNA G+C content of the strain was 58.9 mol%. On the basis of the phylogenetic, phenotypic and genotypic data presented here, strain CCB-MM1 represents a novel species of the genus Microbulbifer, for which the name Microbulbiferaggregans sp. nov. is proposed. The type strain is CCB-MM1 (=LMG 29920=JCM 31875).