Algibacter onchidii sp. nov., a symbiotic bacterium isolated from a marine invertebrate

A novel symbiotic bacterium, designated strain XY-114^T, was isolated from the cerata of an Onchidium marine invertebrate species collected in the South China Sea. Strain XY-114^T was an aerobic, Gram-stain-negative, non-motile and short rod-shaped bacterium (0.5-0.8 µm wide and 1.0-1.5 µm long) without flagellum. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain XY-114^T belonged to the genus Algibacter with the highest similarity of 97.2 % to the closest phylogenetic relative Algibacter aestuarii KYW371^T. Cells grew at 15-37 °C (optimum, 30 °C), at pH 5.5-9.0 (optimum 7.0-8.0) and at NaCl concentrations of 0.5-5.0 % (w/v; optimum 1.5-3.0 %). The major fatty acids (>10 %) were summed feature 3 (comprising C_16 : 1  ω7c and/or C_16 : 1  ω6c), iso-C_15 : 0, iso-C_15 : 1 G and iso-C_17 : 0 3-OH. The predominant polar lipid was phosphatidylethanolamine. The predominant respiratory quinone was MK-6. Flexirubin-type pigments were absent. The genome size of strain XY-114^T was 3.4 Mbp, with 34.9 mol% of DNA G+C content. The average nucleotide identity, digital DNA-DNA hybridization and amino acid identity values between strain XY-114^T and A. aestuarii KYW371^T were 74.5 %, 17.0±1.8 % and 73.9 %. Characterization based on phylogenetic, phenotypic, chemotaxonomic and genomic evidence demonstrated that strain XY-114^T represents a novel species of the genus Algibacter, for which the name Algibacter onchidii sp. nov. is proposed. The type strain is XY-114^T (=KCTC 72217^T=MCCC 1K03606^T).

Palleronia sediminis sp. nov. and Flavivirga algicola sp. nov., two marine bacteria isolated from offshore areas near Weihai

Two bacterial strains, designated SS33^T and Y03^T, were isolated from marine sediment and marine red alga collected on the coast of Weihai, PR China. Based on the results of 16S rRNA gene sequence analysis, strain SS33^T was found to be closely related to Primorskyibacter marinus PX7^T, Pelagivirga dicentrarchi YLY04^T, Palleronia marisminoris DSM 26347^T and Maribius pontilimi GH1-23^T with 94.8, 94.6, 94.5 and 94.5 % sequence similarity; strain Y03^T was found to be closest to Flavivirga aquimarina EC2D5^T, Flavivirga eckloniae ECD14^T and Flavivirga amylovorans JC2681^T with 96.4, 96.1 and 96.0 % sequence similarity. Strain SS33^T grew at 4-37 °C (optimum, 33 °C), at pH 6.0-9.5 (optimum, pH 7.5-8.0) and in the presence of 0-10 % (w/v) NaCl (optimum, 3.0 %). Chemotaxonomic analysis of strain SS33^T showed that the predominant respiratory quinone was ubiquinone-10. The major fatty acids (>10.0 %) included C_18 : 1  ω7c and C_16 : 0. The major polar lipids included phosphatidylglycerol, phosphatidylcholine, one unidentified phospholipid, one unidentified glycolipid, one unidentified polar lipid and two unidentified aminolipids. Strain Y03^T grew at 15-40 °C (optimum, 28 °C), at pH 6.5-8.0 (optimum, pH 7.0) and in the presence of 0.5-9.0 % (w/v) NaCl (optimum, 2.0%). Chemotaxonomic analysis showed that the predominant respiratory quinone was menaquinone-6. The major fatty acids (>10.0 %) included iso-C_15 : 0, iso-C_15 : 1 G, iso-C_17 : 0 3-OH and iso-C_15 : 0 3-OH. The major polar lipids included phosphatidylethanolamine, one unidentified phospholipid, one unidentified aminolipid and four unidentified polar lipids. Based on the polyphasic data, strain SS33^T is considered to represent a novel species of the genus Palleronia, for which the name Palleronia sediminis sp. nov. is proposed, with the type strain SS33^T (=KCTC 62986^T=MCCC 1H00387^T). Strain Y03^T is considered to represent a novel species of the genus Flavivirga, for which the name Flavivirga algicola sp. nov. is proposed, with the type strain Y03^T (=KCTC 72001^T=MCCC 1H00386^T).