RESUMEN
Six mycelium-forming actinomycete strains were isolated from forest soil near the Cisolok geysers in West Java, Indonesia. The 16S rRNA gene sequences of these strains showed high similarity to members of genera in the family Pseudonocardiaceae with values less than 96.0â%, and most closely related to the genus Thermotunica, T. guangxiensis AG2-7T(94.6-95.2â% similarity). The type strain, designated SL3-2-4T, was aerobic, thermophilic, Gram-stain-positive that formed branched, non-fragmented substrate mycelia and unbranched aerial mycelia with long-chain, oval-shaped spores on International Streptomyces Project (ISP) 3 medium. It produced light-orange substrate mycelia and light-orange diffusible pigments on ISP 3 medium with 2â% gellan gum, grown at 30-55 °C, with optimum growth at 45 °C. The pH range for growth was 4.0-8.0, with optimum growth at pH 7.0. Strain SL3-2-4T was able to hydrolyze casein, esculin, gelatin, guanine, hypoxanthine, starch, L-tyrosine, and xanthine, but not adenine, carboxymethyl-cellulose, cellulose, chitin, Tween 20, or xylan. The major fatty acid was iso-C16â:â0, and the major menaquinone was MK-8 (H4). The detected polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidyl-N-methylethanolamine, unidentified aminophospholipids, unidentified glycolipids, and unidentified phospholipids. The cell wall hydrolysate of SL3-2-4T contained meso-2,4-diaminopimelic acid. The whole cell sugars were arabinose and galactose. The DNA G+C content was 71.6 mol%. Phenotypic features and phylogenetic data differentiated SL3-2-4T from members of the family Pseudonocardiaceae. Therefore, the strain SL3-2-4T is proposed as a representative of a novel species in a novel genus, Gandjariella thermophila gen. nov., sp. nov. The type strain is SL3-2-4T (=UICC B-83T=NRRL B-67478T=InaCC A981T).
Asunto(s)
Actinobacteria/clasificación , Bosques , Filogenia , Microbiología del Suelo , Actinobacteria/aislamiento & purificación , Técnicas de Tipificación Bacteriana , Composición de Base , ADN Bacteriano/genética , Ácido Diaminopimélico/química , Ácidos Grasos/química , Glucolípidos/química , Indonesia , Fosfolípidos/química , Pigmentación , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Vitamina K 2/análogos & derivados , Vitamina K 2/químicaRESUMEN
A Gram-stain-positive, endospore-forming, aerobic and thermophilic bacterium, designated strain LC2-13AT, was isolated from Cisolok geyser, West Java, Indonesia, at 50 °C. The isolate was rod-shaped and motile by means of peritrichous flagella. The major cellular fatty acids were iso-C16 : 0, C16 : 0 and anteiso-C15 : 0 and the major quinone was menaquinone 7. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The genomic DNA G+C content was 56.6 mol% and the major diagnostic diamino acid in the cell-wall peptidoglycan was meso-diaminopimelic acid. Phylogenetic analysis based on the 16S rRNA gene sequence indicated that strain LC2-13AT is related most closely to Paenibacillus kobensis DSM 10249T (94.86 % similarity), Paenibacillus tarimensis SA-7-6T (94.77 %) and Paenibacillus barengoltzii SAFN-016T (94.77 %). On the basis of phenotypic, chemotaxonomic and phylogenetic evidence, strain LC2-13AT is affiliated to the genus Paenibacillus, but could be distinguished from recognized species of this genus. A novel species with the name Paenibacillus cisolokensis sp. nov. is thus proposed. The type strain is LC2-13AT (=UICC B-42T=NRRL B-65368T=DSM 101873T).
Asunto(s)
Filogenia , Microbiología del Suelo , Técnicas de Tipificación Bacteriana , Composición de Base , Pared Celular/química , ADN Bacteriano/genética , Ácido Diaminopimélico/química , Ácidos Grasos/química , Indonesia , Hibridación de Ácido Nucleico , Paenibacillus/clasificación , Peptidoglicano/química , Fosfolípidos/química , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Vitamina K 2/análogos & derivados , Vitamina K 2/químicaRESUMEN
A streptogramin type B antibiotic, virginiamycin S (VS), is produced by Streptomyces virginiae, together with a streptogramin type A antibiotic, virginiamycin M1 (VM), as its synergistic counterpart. VS is a cyclic hexadepsipeptide containing a nonproteinogenic amino acid, Lphenylglycine (L-pheGly), in its core structure. We have identified, in the left-hand extremity of the virginiamycin supercluster, two genes that direct VS biosynthesis with L-pheGly incorporation. Transcriptional analysis revealed that visF, encoding a nonribosomal peptide synthetase, and visG, encoding a protein with homology to a hydroxyphenylacetyl-CoA dioxygenase, are under the transcriptional regulation of virginiae butanolide (VB), a small diffusing signalling molecule that governs virginiamycin production. Gene deletion of visG resulted in complete loss of VS production without any changes in VM production, suggesting that visG is required for VS biosynthesis. The abolished VS production in the visG disruptant was fully recovered either by the external addition of pheGly or by gene complementation, which indicates that VisG is involved in VS biosynthesis as the provider of an L-pheGly molecule. A feeding experiment with L-pheGly analogues suggested that VisF, which is responsible for the last condensation step, has high substrate specificity toward L-pheGly.
