Marinihelvus fidelis gen. nov., sp. nov., isolated from marine sediment, and genomic comparison with multiple genera.

A Gram-stain-negative, rod-shaped, non-gliding, non-flagellated, yellow, facultatively aerobic bacterial strain, designated as W260T, was isolated from marine sediment of Xiaoshi Island, Weihai, PR China. The cells of W260T were 0.3-0.5 µm wide and 1.5-2.0 µm long. Strain W260T grows optimally at a temperature of 33 °C (range, 15-37 °C), pH 8 (range, pH 6.5-9.5) and witha NaCl concentration of 3.0 % (w/v; range, 1-8 %). It has the highest sequence similarity to Thiohalobacter thiocyanaticus DSM 21152T (91.7 %), followed by Wenzhouxiangella marina MCCC 1K00261T (91.4 %) and Thiohalospira alkaliphila DSM 17116T (90.7 %). The similarity between strain W260T and the species Thiohalophilus thiocyanatoxydans DSM 16326T was 89.4 %. Genome sequencing revealed a genome size of 3 430 000 bp and a DNA G+C content of 64.5 mol%. The average nucleotide identity and digital DNA-DNA hybridization values between strain W260T and W. marina MCCC 1K00261T were 69.6 and 16.1-20.6 %, respectively. The predominant quinone was ubiquitin-8, and the major fatty acids were iso-C14 : 0 and iso-C16 : 0. The polar lipids consisted of phosphatidylethanolamine, phospholipid, phosphatidylglycerol, diphosphatidylglycerol and four unidentified lipids. Based on phenotypic, phylogenetic and chemotaxonomic information, it was determined that strain W260T represents a novel genus and species and it was given the name Marinihelvus fidelis sp. nov. The type strain is W260T (=MCCC 1H00471T=KCTC 92639T).

Halocynthiibacter halioticoli sp. nov., isolated from the viscera of abalone Haliotis discus hannai.

A Gram-stain-negative, rod-shaped, glide, non-flagellated, and facultatively anaerobic bacterial strain, designated as Z654T, was isolated from the gut of abalone Haliotis discus hannai from Rongcheng, Shandong province, China. Cells are 0.2-0.8 µm in width and 0.7-3.4 µm in length. Cells grew best at 30 °C (range, 15-37 °C), pH 7.0 (range, 6.0-8.5) and NaCl concentration of 2.0% (w/v) (range, 1-10%). According to the phylogenetic analysis of 16S rRNA gene sequence, the strain belongs to the genus Halocynthiibacter and the closest strain is Halocynthiibacter arcticus KCTC 42129 T (97.12%). The genome size of strain Z654T was 3,296,250 bp and the DNA G + C content was 54.2 mol%. The average nucleotide identity (ANI) scores and digital DNA-DNA hybridization (dDDH) scores with H. arcticus KCTC 42129 T were 70% and 14.6-18.2%, respectively. The predominant quinone was Q-10 and the major fatty acids were C18:0, C18:1 ω7c 11-methyl and summed feature 8. The polar lipids consisted of phosphatidylcholine, phosphatidylglycerol, unidentified aminolipid and unidentifed lipids. Based on the phenotypic, phylogenetic and chemotaxonomic data, strain Z654T was considered to represent a novel species of the genus Halocynthiibacter, for which the name Halocynthiibacte halioticoli sp. nov., is proposed. The type strain is Z654T (= MCCC 1H00503T = KCTC 92003 T).

Winogradskyella vincentii sp. nov. and Winogradskyella alexanderae sp. nov., two novel bacteria isolated from intertidal sediment.

Two novel Gram-stain-negative, facultative anaerobic, chemoheterotrophic, non-motile and rod-shaped strains were isolated from intertidal sediment sampled at Xiaoshi Island, Weihai, PR China. Full sequence analysis of the 16S rRNA genes showed that the two strains were closely related to members of the genus Winogradskyella and the phylogenetic similarities to their closest relative, Winogradskyella aquimaris, were 96.7 and 95.8 %, respectively. The DNA G+C contents of strains 2Y89T and D23T were 33.3 and 35.1 mol%, respectively. The respiratory quinone detected in both strains was MK-6. The major fatty acids detected in strain 2Y89T were iso-C15 : 0 and iso-C15 : 1G, and in strain D23T they were iso-C15 : 1G, iso-C15 : 0 and iso-C17 : 03-OH. The principal polar lipids of strain 2Y89T mainly included phosphatidylethanolamine, aminoglycolipids, unidentified aminolipids, unidentified glycolipids and unidentified lipids; strain D23T was the same as strain 2Y89T except that it did not contain aminoglycolipids. Based on the phenotypic, chemical taxonomic, genotypic and phylogenetic features established in this study, we suggest that the new strains represent two novel species of the genus Winogradskyella, for which the names Winogradskyella vincentii sp. nov. (type strain 2Y89T=MCCC 1H00477T=KCTC 92034T) and Winogradskyella alexanderae sp. nov. (type strain D23T=MCCC 1H00462T=KCTC 92023T) are proposed.

Rhodohalobacter sulfatireducens sp. nov., isolated from a marine solar saltern.

A novel Gram-stain-negative, oxidase-positive, catalase-positive, non-motile, facultatively anaerobic, rod-shaped bacterium, designated WB101T, was isolated from a marine solar saltern located in Wendeng, PR China. Strain WB101T shared a high level of 16S rRNA gene sequence similarity with Rhodohalobacter barkolensis 15182T (93.5%), R. halophilus JZ3C29T (93.2%), and 'R. mucosus' 8A47T (92.1%). Strain WB101T formed a species-level branch within the genus Rhodohalobacter in both phylogenetic and phylogenomic topologies. The DNA G + C content was 42.0%. Strain WB101T was found to have menaquinone-7 as the only respiratory quinone. The dominant cellular fatty acid (≥ 10%) was iso-C15:0. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, and phosphatidylcholine. Characterisation based on phylogenetic, physiological, and biochemical properties indicated that strain WB101T represents a novel species of the genus Rhodohalobacter, and the name Rhodohalobacter sulfatireducens sp. nov. is proposed. The type strain is WB101T (= KCTC 92204T = MCCC 1H00518T).