ABSTRACT
A novel Gram-staining-positive actinobacterium with antimicrobial activity, designated CFH 90308T, was isolated from the sediment of a salt lake in Yuncheng, Shanxi, south-western China. The isolate exhibited the highest 16S rRNA gene sequence similarities to Microbacterium yannicii G72T, Microbacterium hominis NBRC 15708T and Microbacterium xylanilyticum S3-ET (98.5, 98.4 and 98.2â%, respectively), and formed a separate clade with M. xylanilyticum S3-ET in phylogenetic trees. The strain grew at 15-40âºC, pH 6.0-8.0 and could tolerate NaCl up to a concentration of 15â% (w/v). The whole genome of strain CFH 90308T consisted of 4.33 Mbp and the DNA G+C content was 69.6 mol%. The acyl type of the peptidoglycan was glycolyl and the whole-cell sugars were galactose and mannose. The cell-wall peptidoglycan mainly contained alanine, glycine and lysine. The menaquinones of strain CFH 90308T were MK-12, MK-13 and MK-11. Strain CFH 90308T contained anteiso-C15:0, anteiso-C17:0, iso-C16:0 and iso-C15:0 as the predominant fatty acids. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between CFH 90308T and the other species of the genus Microbacterium were found to be low (ANIb <81.3â%, dDDH <25.6â%). The secondary metabolite produced by strain CFH 90308T showed antibacterial activities against Bacillus subtilis, Pseudomonas syringae, Aeromonas hydrophila and methicillin-resistant Staphylococcus aureus. Based on genotypic, phenotypic and chemotaxonomic results, the isolate is considered to represent a novel species of the genus Microbacterium, for which the name Microbacterium salsuginis sp. nov. is proposed. The type strain is CFH 90308T (=DSM 105964T=KCTC 49052T).
Subject(s)
Bacterial Typing Techniques , Base Composition , DNA, Bacterial , Fatty Acids , Geologic Sediments , Microbacterium , Phylogeny , RNA, Ribosomal, 16S , Sequence Analysis, DNA , Vitamin K 2 , RNA, Ribosomal, 16S/genetics , DNA, Bacterial/genetics , China , Vitamin K 2/analogs & derivatives , Geologic Sediments/microbiology , Peptidoglycan , Lakes/microbiology , Nucleic Acid Hybridization , Sodium Chloride/metabolism , Genome, BacterialABSTRACT
An isolate, designated CFH 74404T, was recovered from a hot spring in Tengchong, Yunnan province, PR China. Phylogenetic analysis indicated that the isolate belongs to the family Thermomicrobiaceae and showed the highest 16S rRNA gene sequence similarity to Thermorudis peleae KI4T (93.6â%), Thermorudis pharmacophila WKT50.2T (93.1â%), Thermomicrobium roseum DSM 5159T (92.0â%) and Thermomicrobium carboxidum KI3T (91.7â%). The average amino acid identity and average nucleotide identity values between strain CFH 74404T and the closest relatives were 42.0-75.9â% and 67.0-77.3â%, respectively. Cells of strain CFH 74404T stained Gram-positive and were aerobic, non-motile and short rod-shaped. Growth occurred at 20-65 °C (optimum, 55 °C), pH 6.0-8.0 (optimum, pH 7.0) and with up to 2.0â% (w/v) NaCl (optimum 0-1.0â%, w/v). The predominant respiratory quinone was MK-8. The major fatty acids (>10â%) were C18â:â0 (50.8â%) and C20â:â0 (16.8â%). The polar lipid profile of strain CFH 74404T included diphosphatidylglycerol, four unidentified phosphoglycolipids, phosphatidylinositol and three unidentified glycolipids. The G+C content of the genomic DNA was determined to be 67.1 mol% based on the draft genome sequence. On the basis of phenotypic, phylogenetic and genotypic analyses, it is concluded that strain CFH 74404T represents a new species of a novel genus Thermalbibacter of the family Thermomicrobiaceae, for which the name Thermalbibacter longus gen. nov., sp. nov. is proposed. The type strain is CFH 74404T (=KCTC 62930T=CGMCC 1.61585T).
