Pseudopontivivens aestuariicola gen. nov., sp. nov., a Novel Bacterium of the Class Alphaproteobacteria Isolated from a Tidal Flat

A Gram-stain-negative, non-motile and coccoid, ovoid or rod-shaped bacterial strain, OITF-57^T, which was isolated from a tidal flat sediment in South Korea, was characterized taxonomically. Strain OITF-57^T grew optimally at 25 °C, at pH 7.0–8.0 and in the presence of 2.0% (w/v) NaCl. Strain OITF-57^T exhibited the highest 16S rRNA gene sequence similarity value (94.2%) to the type strain of Pontivivens insulae forming a cluster in the neighbour-joining phylogenetic tree. In the maximum-likelihood and maximum-parsimony phylogenetic trees based on 16S rRNA gene sequences and the phylogenetic tress based on gyrB sequences, strain OITF-57^T formed evolutionary lineages independent of those of other taxa. Strain OITF-57^T contained Q-10 as the predominant ubiquinone and C_18:1ω7c as the major fatty acid. The major polar lipids of strain OITF-57^T were phosphatidylcholine and phosphatidylglycerol. The DNA G + C content of strain OITF-57^T was 66.0 mol%. The chemotaxonomic data and other differential phenotypic properties made it possible to distinguish strain OITF-57^T from the genus Pontivivens and other phylogenetically related genera. On the basis of the data presented, strain OITF-57^T constitutes a new genus and species within the class Alphaproteobacteria, for which the name Pseudopontivivens aestuariicola gen. nov., sp. nov. is proposed. The type strain is OITF-57^T (= KACC 19570^T = CGMCC 1.13481^T).