Nioella aestuarii sp. nov., of the family Rhodobacteraceae, isolated from tidal flat

Abyssibius alkaniclasticus gen. nov., sp. nov., a novel member of the family Rhodobacteraceae, isolated from the Mariana Trench

A Gram-stain-negative bacterium with rod-shaped or irregular cells approximately 0.5-0.9×2.0-3.8 µm in size, designated as 960558^T, was isolated from sediment sampled in the Mariana Trench. Strain 960558^T grows at 4-37 °C (optimum, 28 °C), pH 6-7 (optimum, pH 7) and in the presence of 1-5 % (w/v) NaCl (optimum, 3 %). Strain 960558^T utilizes tetradecane or hexadecane as a sole carbon and energy source, respectively. Phylogenetic trees based on 16S rRNA gene sequences and phylogenomic reconstruction revealed a close phylogenetic relationship between strain 960558^T and members of the family Rhodobacteraceae by forming a separate branch within the type species of closely related genera. The validly published species that is most closely related to strain 960558^T is Planktotalea lamellibrachiae JAM 119^T, which has the highest 16S rRNA gene sequence similarity (93.47 %). Ubiquinone 10 is the predominant ubiquinone, while C_16 : 0, 11-methyl C_18 : 1  ω7c and C_18 : 1  ω7c and/or C_18 : 1  ω6c are the predominant fatty acids (>10 %). Additionally, phosphatidylglycerol, glycolipids, diphosphatidylglycerol, unidentified polar lipids and unidentified aminolipids are the major polar lipids. The DNA G+C content of strain 960558^T is 61 %. Average nucleotide identity and digital DNA-DNA hybridization results of strain 960558^T with other type strains are <70.2 and 22.1 %, respectively. Based on its phylogenetic, chemotaxonomic and other phenotypic properties, strain 960558^T is considered to represent a novel genus and species within the family Rhodobacteraceae, for which the name Abyssibius alkaniclasticus gen. nov., sp. nov. is proposed. The type strain of Abyssibius alkaniclasticus is 960558^T (=KCTC 82619^T=MCCC 1K04727^T).

Harenicola maris gen. nov., sp. nov. isolated from the Sea of Japan shallow sediments

A Gram-negative, non-motile bacterium КMM 3653^T was isolated from a sediment sample from the Sea of Japan seashore, Russia. On the basis of the 16S rRNA gene sequence analysis the strain КMM 3653^T was positioned within the family Rhodobacteraceae (class Alphaproteobacteria) forming a distinct lineage with the highest gene sequence similarities to the members of the genera Pacificibacter (95.2-94.7%) and Nioella (95.1-94.5%), respectively. According to the phylogenomic tree based on 400 conserved protein sequences, strain КMM 3653^T was placed in the cluster comprising Vannielia litorea, Nioella nitratireducens, Litoreibacter albidus and Pseudoruegeria aquimaris as a separate lineage adjacent to V. litorea KCTC 32083^T. The average nucleotide identity values between strain КMM 3653^T and V. litorea KCTC 32083^T, N. nitratireducens KCTC 32417^T, L. albidus KMM 3851^T, and P. aquimaris CECT 7680^T were 71.1, 70.3, 69.6, and 71.0%, respectively. Strain КMM 3653^T contained Q-10 as the predominant ubiquinone and C_18:1ω7c as the major fatty acid followed by C_16:0. The polar lipids were phosphatidylcholine, phosphatidylglycerol, diphosphatidylglycerol, an unidentified phospholipid, two unidentified aminolipids, and five unidentified lipids. The DNA G+C content of 61.8% was calculated from the genome sequence. Based on the phylogenetic evidence and distinctive phenotypic characteristics, we proposed strain KMM 3653^T (= KCTC 82575^T) to be classified as a novel genus and species Harenicola maris gen. nov., sp. nov.

Alterinioella nitratireducens gen. nov., sp. nov., Isolated from Seawater in the West Pacific Ocean

A novel Gram-negative, nonspore forming, nonmotile, and short-rod-shaped aerobic bacterium, designated DY48A3-103^T, was isolated from a seawater sample collected from the West Pacific Ocean. Strain DY48A3-103^T showed oxidase-positive and catalase-positive activities. Growth was observed at 10-37 °C (optimum 30 °C), at pH 6.5-9.5 (optimum 8.0) and in 1-11% NaCl (optimum 3%, w/v). 16S rRNA gene sequence analysis exhibited 96.3%, 96.1%, 96.0%, and 94.9% sequence similarity to the type strains Rhodophyticola porphyridii MA-7-27^T, Nioella sediminis JS7-11^T, N. nitratireducens SSW136^T, and Jannaschia helgolandensis DSM 14858^T, respectively. Strain DY48A3-103^T and the type strains of phylogenetically related species have 61.7-75.4% AAI values, which fell into to the genus boundary range (60-80% AAI). Phylogenetic trees based on the 16S rRNA gene sequences and the genome sequences of strain DY48A3-103^T revealed that it was affiliated to the members of the family Rhodobacteraceae. The G+C content was 65.4%. The sole isoprenoid quinone was Q-10. The predominant polar lipids were phosphatidylcholine and phosphatidylglycerol. Major fatty acids were summed feature 8 (comprising C_18:1ω7c and/or C_18:1ω6c), C_19:0 cyclo ω8c, and C_16:0. On the basis of the phenotypic, chemotaxonomic, and genomic properties, strain DY48A3-103t is proposed to represent a novel genus and a novel species, Alterinioella nitratireducens gen. nov., sp. nov., in the family Rhodobacteraceae. The type strain is DY48A3-103^T (= KCTC 72738^T = MCCC 1K04322^T).

Nioella ostreopsis sp. nov., isolated from toxic dinoflagellate, Ostreopsis lenticularis

A novel short-rod-shaped bacterial strain with poly-β-hydroxybutyric acid granules inside, designated as Z7-4^T, was isolated from a culture of a marine dinoflagellate with palytoxin-producing capacity, Ostreopsis lenticularis OS06, collected from the East China Sea. Cells of Z7-4^T were Gram-stain-negative, non-motile, strictly aerobic, 0.9-1.2 µm wide and 2.0-3.9 µm long. Growth occurred in 1-4 % (w/v) NaCl, at 15-37 °C and at pH 5.0-10.0, with optimum growth in 3.5 % (w/v) NaCl, at 30 °C and at pH 7.0. Analysis of 16S rRNA gene sequence revealed that Z7-4^T shared the highest 16S rRNA gene sequence similarities with Nioella aestuarii JCM 30752^T (98.8 %), followed by Nioella sediminis KCTC 42144^T (98.6 %) and Nioella nitratireducens KCTC 32417^T (96.9 %). Phylogenetic analysis based on nearly complete 16S rRNA gene sequences revealed that Z7-4^T clearly represented a member of the genus Nioella within the family Rhodobacteraceae. The respiratory quinone of Z7-4^T was identified as Q-10. Polar lipids of Z7-4^T were phosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, three unidentified aminophospholipids and one unidentified phospholipid. The major fatty acids were summed feature 8 (C_18 : 1ω7c and/or C_18 : 1ω6c) and C_16 : 0. The DNA G+C content of Z7-4^T was 63.0 mol%. DNA-DNA hybridization values of the isolate against the closely related type strains were far below the 70 % limit for species delineation. The average nucleotide identity and in silico DNA-DNA genome hybridization relatedness between Z7-4^T and the closely related members of the genus Nioella, N. sediminis KCTC 42144^T and N. nitratireducens KCTC 32417^T, were 91.1 and 46.3 %, and 79.3 and 19.4 %, respectively. On the basis of the results of polyphasic analysis, Z7-4^T is proposed to represent a novel species of the genus Nioella, for which the name Nioella ostreopsis sp. nov. is proposed. The type strain of Nioella ostreopsis is Z7-4^T (=KCTC 62459^T=CCTCC AB 2017231^T).