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

Abstract

A Gram-stain-negative, non-motile and coccoid, ovoid or rod-shaped bacterial strain, OITF-57, which was isolated from a tidal flat sediment in South Korea, was characterized taxonomically. Strain OITF-57 grew optimally at 25 °C, at pH 7.0-8.0 and in the presence of 2.0% (w/v) NaCl. Strain OITF-57 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 formed evolutionary lineages independent of those of other taxa. Strain OITF-57 contained Q-10 as the predominant ubiquinone and C ω7c as the major fatty acid. The major polar lipids of strain OITF-57 were phosphatidylcholine and phosphatidylglycerol. The DNA G + C content of strain OITF-57 was 66.0 mol%. The chemotaxonomic data and other differential phenotypic properties made it possible to distinguish strain OITF-57 from the genus Pontivivens and other phylogenetically related genera. On the basis of the data presented, strain OITF-57 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 (= KACC 19570 = CGMCC 1.13481).