Dyadobacter beijingensis

Abstract: A Gram-stain-negative, non-motile, rod-shaped bacterial strain, L-1T, which was capable of degrading methyl red was isolated from a dye-manufacturing factory in China. Phenotypic, chemotaxonomic and phylogenetic analyses established affiliation of the isolate to the genus Dyadobacter . Cells occurred in pairs in young cultures but became chains of coccoid cells in old cultures, and produced a flexirubin-like yellow pigment. Strain L-1T could not hydrolyse cellulose, and had a DNA G+C content of 51.3 mol%. The major cellular fatty acids were iso-C15 : 0, C16 : 1ω5c, iso-C17 : 0 3-OH and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c). C16 : 0, iso-C15 : 0 3-OH and C16 : 0 3-OH were the other major fatty acid components. Comparative 16S rRNA gene sequence analysis showed that strainL-1T was most closely related to Dyadobacter fermentans DSM 18053T (99.2 %), Dyadobacter soli JCM 16232T (98.9 %) and Dyadobacter beijingensis CGMCC 1.6375T (98.7 %). However, the new isolate exhibited relatively low levels of DNA–DNA relatedness with respect to JCM 16232T (41.2±1.8 %), DSM 18053T (38.6±2.6 %) and CGMCC 1.6375T (35.0±2.1 %). Strain L-1T could also be differentiated from its closest phylogenetic relatives based on differences in several phenotypic characteristics. These data suggest that strain L-1T represents a novel species of the genus Dyadobacter , for which the name Dyadobacter jiangsuensis sp. is proposed. The type strain is L-1T (DSM 29057T = CGMCC 1.12969T).

Abstract: A novel Gram-stain-negative, aerobic and rod-shaped bacterial strain, designated 65T, was isolated from surface-sterilized root tissue of maize, collected from Fangshan District of Beijing, People's Republic of China, and was subjected to a taxonomic study by using a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain 65T belonged to the genus Dyadobacter and had highest 16S rRNA gene sequence similarity to Dyadobacter jiangsuensis CGMCC 1.12969T (99.1 %), Dyadobacter beijingensis CGMCC 1.6375T (98.8 %), Dyadobacter fermentans DSM 18053T (98.6 %) and Dyadobacter soli KCTC 22481T (98.6 %). However, the new isolate exhibited relatively low levels of DNA-DNA relatedness with respect to D. jiangsuensis CGMCC 1.12969T (18.2±1.3 %), D. beijingensis CGMCC 1.6375T (14.2±2.0 %), D. fermentans DSM 18053T (14.1±2.0 %) and D. soli KCTC 22481T (13.8±0.6 %). The predominant respiratory quinone was menaquinone-7 (MK-7) and the major cellular fatty acids were summed feature 3 (C16 : 1ω7c and/or iso-C15 : 0 2-OH), iso-C15 : 0, iso-C17 : 0 3-OH, C16 : 1ω5c, iso-C15 : 0 3-OH, C16 : 0 3-OH and C16 : 0. The polar lipid profile of strain 65T revealed the presence of phosphatidylethanolamine, four aminolipids and two unidentified phospholipids. The DNA G+C content was 46.6 mol%. The results of physiological and biochemical tests and the differences in the fatty acid profiles allowed the clear phenotypic differentiation of strain 65T from closely related species of the genus Dyadobacter. Strain 65T thus represents a novel species within the genus Dyadobacter, for which the name Dyadobacterendophyticus sp. nov. is proposed. The type strain is 65T (=CGMCC 1.15288T=DSM 100786T).

Abstract: A Gram-negative, non-motile, aerobic bacterial strain, designated MJ20T, was isolated from farm soil near Daejeon (South Korea) and was characterized taxonomically by using a polyphasic approach Comparative 16S rRNA gene sequence analysis showed that strain MJ20T belongs to the family Cytophagaceae, class Sphingobacteria, and was related most closely to Dyadobacter fermentans DSM 18053T (989 % sequence similarity), Dyadobacter beijingensis JCM 14200T (980 %) and Dyadobacter ginsengisoli KCTC 12589T (964 %) The G+C content of the genomic DNA of strain MJ20T was 485 mol% The detection of MK-7 as the predominant menaquinone and a fatty acid profile with summed feature 4 (C16 : 1 ω7c and/or iso-C15 : 0 2-OH), iso-C15 : 0, C16 : 0 and C16 : 1 ω5c as major components supported the affiliation of strain MJ20T to the genus Dyadobacter The new isolate exhibited relatively low levels of DNA–DNA relatedness with respect to D fermentans DSM 18053T (mean±sd of three determinations, 47±7 %) and D beijingensis JCM 14200T (38±8 %) On the basis of its phenotypic and genotypic properties together with phylogenetic distinctiveness, strain MJ20T (=KCTC 22481T =JCM 16232T) should be classified in the genus Dyadobacter as the type strain of a novel species, for which the name Dyadobacter soli sp nov is proposed