ABSTRACT
A Gram-stain-negative, aerobic, non-motile, rod-shaped and non-spore-forming bacterium, designated EF23T, was isolated from rhizosphere soil of watermelon. Growth of strain EF23T was observed at 10-37 °C, at pH 5.0-9.0 and in the presence of 0-0.5â% (w/v) NaCl. Strain EF23T contained menaquinone 7 (MK-7) as the major isoprenoid quinone, and summed feature 3 (C16:1ω7c and/or iso-C15â:â0 2-OH), iso-C15â:â0, C16â:â0 and iso-C17â:â0 3-OH as the major fatty acids. Phosphatidylethanolamine was identified as the major polar lipid. The genomic DNA G+C content of strain EF23T was 43.7 mol%. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain EF23T was most closely related to Mucilaginibacter gossypii Gh-67T (98.9â% similarity) and Mucilaginibacter gossypiicola Gh-48T (97.6â%). DNA-DNA relatedness values between strain EF23T and M. gossypii KCTC 22380T and M. gossypiicola KCTC 22379T were 31.6 and 53.7â%. On the basis of the evidence presented in this polyphasic taxonomic study, strain EF23T is considered to represent a novel species of the genus Mucilaginibacter, for which the name Mucilaginibacter rubeus sp. nov. is proposed. The type strain is EF23T (=CGMCC 1.15913T=KCTC 52516T).
Subject(s)
Bacteroidetes/classification , Citrullus/microbiology , Phylogeny , Rhizosphere , Soil Microbiology , Bacterial Typing Techniques , Bacteroidetes/genetics , Bacteroidetes/isolation & purification , Base Composition , China , DNA, Bacterial/genetics , Fatty Acids/chemistry , Phosphatidylethanolamines/chemistry , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA , Vitamin K 2/analogs & derivatives , Vitamin K 2/chemistryABSTRACT
The Gram-reaction-negative, aerobic, white- to pale-yellow-coloured and rod-shaped bacterium with a single polar flagellum or a stalk, designated strain 7F14T, was isolated from rhizosphere soil of cultivated watermelon (Citrullus lanatus) collected from Hefei, China. Growth of strain 7F14T was observed at pH 6.0-9.0, 10-30 °C and in the presence of 0-1â% (w/v) NaCl. Cells were catalase-negative and oxidase-positive. Phylogenetic analyses based on 16S rRNA gene sequences indicated that strain 7F14T formed a phyletic lineage within the genus Caulobacter of the family Caulobacteraceae and showed the highest 16S rRNA gene sequence similarities to Caulobacter henricii ATCC 15253T (98.66â%), Caulobacter segnis ATCC 21756T (98.27â%), Caulobacter vibrioides CB51T (97.92â%) and Caulobacter flavus RHGG3T (97.44â%). The G+C content of the genomic DNA was 68.6 mol%. Strain 7F14T contained Q-10 as the sole ubiquinone and 11-methyl C18â:â1ω7c, C18â:â1ω7c, C16â:â0 and summed feature 3 (C16â:â1ω7c and/or iso-C15â:â0 2-OH) as the major fatty acids. The polar lipids profile consisted of phosphatidylglycerol, an unknown phosphoglycolipid, five unknown glycolipids, an unknown phospholipid and three unknown lipids. DNA-DNA relatedness values to the most closely related type strains Caulobacter henricii DSM 4730T and Caulobacter segnis DSM 7131T were 26.0 and 19.7â%, respectively. Based on unique phenotypic traits, and phylogenetic, chemotaxonomic and DNA-DNA hybridization results, strain 7F14T should be classified as a representative of a novel species of the genus Caulobacter, for which the name Caulobacter rhizosphaerae sp. nov. is proposed. The type strain is 7F14T (=CGMCC 1.15915T=KCTC 52515T).
Subject(s)
Caulobacter/classification , Phylogeny , Rhizosphere , Soil Microbiology , Bacterial Typing Techniques , Base Composition , Caulobacter/genetics , Caulobacter/isolation & purification , China , DNA, Bacterial/genetics , Fatty Acids/chemistry , Nucleic Acid Hybridization , Phospholipids/chemistry , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA , Ubiquinone/chemistryABSTRACT
A Gram-stain-negative, aerobic, yellow-pigmented and rod-shaped bacterium with a single polar flagellum or a stalk, designated strain RHGG3T, was isolated from rhizosphere soil of cultivated watermelon (Citrullus lanatus) collected from Hefei, China. Optimal growth of strain RHGG3T was observed at pH 7.0 and 28-30 °C. Cells were catalase-positive and oxidase-negative. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain RHGG3T belonged to the genus Caulobacter and showed the highest 16S rRNA gene sequence similarities to Caulobacter segnis ATCC 21756T (98.6 %), Caulobacter vibrioides CB51T (98.3 %) and Caulobacter henricii ATCC 15253T (97.2 %). The G+C content of the genomic DNA was 70âmol%. Strain RHGG3T contained Q-10 as the sole ubiquinone and the major fatty acids (>8 %) were 11-methyl C18 : 1ω7c, C18 : 1ω7c, C16 : 0, C15 : 0 and summed feature 3 (C16 : 1ω7c and/or iso-C15 : 0 2-OH). The polar lipids were various unknown glycolipids, phosphatidylglycerol and phosphoglycolipids. DNA-DNA relatedness of strain RHGG3T to type strains of the most closely related species (Caulobacter segnis ATCC 21756T, Caulobacter vibrioides DSM 4738 and Caulobacter henricii ATCC 15253T) was 32.4-40.9 %. Based on polyphasic taxonomy analysis (phylogenetic, unique phenotypic traits, chemotaxonomic and DNA-DNA hybridizations), strain RHGG3T represents a novel species of the genus Caulobacter, for which the name Caulobacter flavus sp. nov. is proposed. The type strain is RHGG3T ( = CGMCC 1.15093T = KCTC 42581T = JCM 30763T).
