A Gram-staining-negative, aerobic, non-motile, rod-shaped bacterium, designated as P308H10T, was isolated from surface sediment of the Southern Indian Ocean. Growth occurred at 4-36 °C (optimum 20-25 °C), pH 6.0-8.5 (optimum 7.5-8.0) and in the presence of 1-8 % (w/v) NaCl (optimum 2-3 %). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain P308H10T lies within the clade of members of the genus Arenibacter and is closely related to Arenibacterhampyeongensis HP12T (98.0 %), Arenibacterechinorum KMM 6032T (98.4 %), Arenibacterpalladensis LMG 21972T (97.9 %), Arenibactertroitsensis KMM 3674T (97.9 %) and 'Arenibacter algicola' TG409 (98.1 %). The average nucleotide identity and digital DNA-DNA hybridization values between strain P308H10T and the five reference strains were 85.9-80.6 % and 30.2-23.6 %, respectively. The major fatty acids (>10 %) of strain P308H10T were summed feature 3, iso-C17 : 0 3-OH, iso-C15 : 1 G and iso-C15 : 0. The major polar lipids comprised phosphatidylethanolamine, five unidentified aminolipids and four unidentified lipids. The only respiratory quinone was menaquinone-6. The genomic DNA G+C content was 38.2 mol%. On the basis of the phenotypic, phylogenetic and chemotaxonomic data presented, strain P308H10T represents a novel species of the genus Arenibacter, for which the name Arenibacter catalasegens sp. nov. is proposed. The type strain is P308H10T (=GDMCC 1.1230T=KCTC 52983T). An emended description of the genus Arenibacter is also proposed.
Keywords: Antarctica; Arenibacter; Flavobacteriaceae; Ross Sea; marine sediment; polyphasic taxonomy.