No abstract

Two Gram-stain-negative, strictly aerobic bacteria, strains L1-7-SET and R6, isolated from marine red algae, were characterized. They shared 99.9 % 16S rRNA gene sequence similarity and a 100 % digital DNA–DNA hybridization (DDH) value, representing members of a single species. Cells of strains L1-7-SET and R6 were catalase- and oxidase-positive motile rods with a single polar flagellum. Strains L1-7-SET and R6 optimally grew at 30–35 °C, pH 7.0–8.0 and with 1.0–2.0 % (w/v) NaCl. Ubiquinone-10 was the sole isoprenoid quinone and C19 : 0 cyclo ω8c and summed feature 8 (comprising C18 : 1  ω7c and/or C18 : 1  ω6c) were detected as the major cellular fatty acids. The DNA G+C contents of strains L1-7-SET and R6 were both 61.62 mol%. The polar lipids of strain L1-7-SET consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, an unidentified aminolipid, an unidentified phospholipid and two unidentified polar lipids. Phylogenetic analyses based on 16S rRNA gene and 120 protein marker sequences revealed that strains L1-7-SET and R6 formed a phyletic lineage within the genus Nitratireductor and they were most closely related to Nitratireductor aquibiodomus NL21T and Nitratireductor kimnyeongensis KY 101T with both 98.8 % 16S rRNA gene sequence similarities. Digital DDH values between strain L1-7-SET and the type strains of N. aquibiodomus and N. kimnyeongensis were 60.3 and 29.5 %, respectively. The phenotypic, chemotaxonomic and molecular features support that strains L1-7-SET and R6 represents a novel species of the genus Nitratireductor , for which the name Nitratireductor rhodophyticola sp. nov. is proposed. The type strain is L1-7-SET (=KACC 19076T=KCTC 92231T=JCM 31802T).

Two Gram-stain-negative, aerobic and yellow-pigmented bacterial strains, designated K20-16T and MSW2, were isolated from a marine red alga (Chondrus species) and seawater, respectively. Both strains were oxidase-positive, weakly catalase-positive and non-flagellated rods with gliding motility. Menaquinone-6 was detected as the sole isoprenoid quinone in both strains. Iso-C15:0, iso-C15:0 3-OH, iso-C15:1 G, C15:1 ω6c and summed feature 3 (comprising C16:1 ω7c and/or C16:1 ω6c) were identified in both strains as major fatty acids. Phosphatidylethanolamine was not identified in strain K20-16T, but it was identified in strain MSW2. The genomic DNA G+C contents of strains K20-16T and MSW2 were 30.5 and 30.7 %, respectively. Strains K20-16T and MSW2 shared 99.7% 16S rRNA gene sequence similarity, 97.7% average nucleotide identity (ANI), and 80.5% digital DNA–DNA hybridization (DDH) value, indicating that they are the same species. Phylogenetic analyses based on 16S rRNA gene and 92 concatenated core protein sequences revealed that strains K20-16T and MSW2 formed a phylogenic lineage within the genus Tenacibaculum and were most closely related to Tenacibaculum todarodis LPB0136T with 98.3 and 98.0% 16S rRNA gene sequence similarities, respectively. ANI and digital DDH values between strains K20-16T and MSW2 and other type strains were less than 91.4 and 43.1 %, respectively. Based on the phenotypic, chemotaxonomic and molecular features, strains K20-16T and MSW2 represent a novel species of the genus Tenacibaculum , for which the name Tenacibaculum aquimarinum sp. nov. is proposed. The type strain is K20-16T (=KACC 22 342T=JCM 35 023T).

Strain MaA-C15T, a Gram-stain-negative, non-spore-forming and strictly aerobic bacterium, was isolated from a xenic culture of Microcystis aeruginosa in the Republic of Korea. Cells were motile rods showing positive reactions in catalase and oxidase tests. Growth was observed between 15 and 37 °C (optimum, 30 °C), between pH 6.0 and pH 11.0 (optimum, pH 7.5) and in the presence of 0–2.0 % (w/v) NaCl (optimum, 0 %). Strain MaA-C15T contained C16 : 0, 11-methyl-C18 : 1  ω7c, cyclo-C19 : 0  ω8c and summed feature 8 (C18 : 1  ω6c and/or C18 : 1  ω7c) as the major cellular fatty acids and ubiquinone-10 as the sole respiratory quinone. Phosphatidylethanolamine, phosphatidylmonomethylethanolamine, an unidentified aminophospholipid, an unidentified glycolipid and three unidentified phospholipids were detected as the major polar lipids. The G+C content of the genomic DNA was 64.1 mol%. Phylogenetic and phylogenomic analyses based on 16S rRNA gene and genome sequences revealed that strain MaA-C15T formed a phyletic lineage with Mesorhizobium sediminum YIM M12096T within the family Phyllobacteriaceae . Strain MaA-C15T was most closely related to Mesorhizobium albiziae DSM 21822T with a 98.2 % 16S rRNA sequence similarity. Average nucleotide identity and in silico DNA–DNA hybridization values between strain MaA-C15T and M. albiziae DSM 21822T were 75.4 and 20.1 %, respectively. Based on the results of phenotypic, chemotaxonomic and molecular analyses, strain MaA-C15T represents a novel species of the genus Mesorhizobium , for which the name Mesorhizobium microcysteis sp. nov. is proposed. The type strain is MaA-C15T (=KACC 21226T=JCM 33503T).

A Gram-stain-negative, yellow-pigmented and facultatively aerobic bacterium, designated strain U1T, was isolated from plastic dumped soil sampled in the Republic of Korea. Cell of strain U1T were non-motile rods showing catalase-negative and oxidase-positive activities. Strain U1T was shown to grow at 10–37 °C (optimum, 25–30 °C) and pH 6.0–9.0 (optimum, pH 8.0), and in the presence of 0–0.5 % (w/v) NaCl (optimum, 0 %). Strain U1T contained iso-C15 : 0, C16 : 0, C16 : 1 ω5c and summed feature 3 (comprising C16 : 1  ω6c and/or C16 : 1 ω7c) as the major cellular fatty acids (>5 %) and menaquinone-7 as the sole respiratory quinone. Phosphatidylethanolamine, two unidentified aminolipids and three unidentified lipids were identified as the major polar lipids. The DNA G+C content of strain U1T calculated from the whole-genome sequence was 45.5 mol%. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain U1T formed a distinct phylogenetic lineage within the genus Dyadobacter . Strain U1T has the highest 16S rRNA sequence similarity to Dyadobacter bucti QTA69T (97.9 %). Average nucleotide identity and digital DNA–DNA hybridization values between strain U1T and D. bucti QTA69T were 74.6 % and 18.9 %, respectively. Based on phenotypic, chemotaxonomic and molecular features, strain U1T represents a novel species of the genus Dyadobacter , for which the name Dyadobacter pollutisoli sp. nov. is proposed. The type strain is U1T (= KACC 22210T=JCM 34491T).