Pontimicrobium aquaticum gen. Nov., sp. nov., a bacterium in the family flavobacteriaceae isolated from seawater

Abstract

A Gram-stain-negative, yellow-pigmented, non-spore-forming, non-motile, rod-shaped, catalase-positive, strictly aerobic bacterial strain, designated CAU 1491T, was isolated from seawater and its taxonomic position was examined using a polyphasic approach. Cells of strain CAU 1491T grew optimally at 30 °C, pH 7.5 and in 2.0% (w/v) NaCl. Phylogenetic analysis based on the 16S rRNA gene sequence of CAU 1491T showed that it formed a distinct lineage within the family Flavobacteriaceae as a separate deep branch, with 97.0% or lower sequence similarity to representatives of the genera Lacinutrix, Gaetbulibacter and Aquibacter. The major cellular fatty acids of strain CAU 1491T were iso-C15:0, iso-C15:1 G, iso-C17:0 3-OH and summed feature 3. The polar lipid pattern consisted of diphosphatidylglycerol, phosphatidylserine, phosphatidylethanolamine and an unidentified phospholipid. The strain contained MK-6 as the sole respiratory quinone. Genome sequencing revealed that strain CAU 1491T has a genome size of 3.13 Mbp and a G+C content of 32.4 mol%. On the basis of the phenotypic, chemotaxonomic and genomic data, strain CAU 1491T represents a new genus and species in the family Flavobacteriaceae for which the name Pontimicro-bium aquaticum gen. nov., sp. nov. is proposed. The type strain of Pontimicrobium aquaticum is CAU 1491T (=KCTC 72003T=NBRC 113695T). © 2020, Microbiology Society. All rights reserved.