Marinobacter denitrificans sp. nov., isolated from marine sediment of southern Scott Coast, Antarctica

Abstract

A novel bacterium, designated JB02H27T, was isolated from marine sediment collected from the southern Scott Coast, Antarctica. Cells were Gram-stain-negative, facultatively anaerobic, polar-flagellated and motile rods. Growth occurred at 4-45 °C, at pH 7.0-9.0 and with 3-25 % (w/v) NaCl. Phylogenetic trees based on 16S rRNA gene sequences showed that strain JB02H27T consistently fell within the genus Marinobacter and formed a clade together with Marinobacter algicola DG893T (98.8 % similarity), Marinobacter confluentis KCTC 42705T (98.4 %), Marinobacter salarius R9SW1T (98.4%) and Marinobacter halotolerans CP12T (97.9 %), which were subsequently used as reference strains for comparisons of phenotypic and chemotaxonomic characteristics. Average nucleotide identity values between strain JB02H27T and the four related type strains were 80.9, 76.6, 81.9 and 76.3 %, respectively. The major fatty acids were summed feature 3, C16 : 0, C18 : 1 ω9c and C16 : 0 N alcohol. The polar lipids included phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, and an unidentified phospholipid, aminolipid, aminophospholipid and glycolipids. The sole respiratory quinone was ubiquinone-9. The DNA G+C content was 56.9 mol%. Based on the genomic, phylogenetic, phenotypic and chemotaxonomic analysis, we propose that strain JB02H27T represents a novel species of the genus Marinobacter, for which the name Marinobacter denitrificans sp. nov. is proposed. The type strain is JB02H27T (=GDMCC 1.1528T=KCTC 62941T).