A probability matrix for identification of some Streptomycetes. (57/82)

The character state data obtained for clusters defined at the 77.5% SSM similarity level in the phenetic numerical classification described by Williams et al. (1983) were used to construct a probabilistic identification matrix. The 23 phena included were the major clusters (19 Streptomyces, 2 Streptoverticillium and 'Nocardia' mediterranea) and one minor cluster (Streptomyces fradiae). The characters most diagnostic for these clusters were selected using Sneath's CHARSEP and DIACHAR programs. The resulting matrix consisted of 41 characters x 23 phena. Identification scores, determined by Sneath's MATIDEN program were used to evaluate the matrix. Theoretical assessment was achieved by determination of the cluster overlap (OVERMAT), the identification scores for the Hypothetical Medium Organism of each cluster (MOSTTYP), and the scores for randomly selected cluster representatives using the classification data of Williams et al. (1983). The matrix was evaluated practically by the independent re-determination of the characters for the same cluster representatives, which also provided a measure of test error. Finally it was used to identify unknown isolates from a range of habitats. The results showed that the matrix was theoretically sound. Test error was within acceptable limits and did not distort identifications. Of the unknown isolates, 80% were clearly identified with a cluster. It is suggested that the matrix could form the basis for a more objective identification and grouping of the large number of Streptomyces species which have been described.  (+info)

Taxonomic study and fermentation of producing organism and antimicrobial activity of mildiomycin. (58/82)

A taxonomic study of strain B-98891, which produced an antibiotic effective against powdery mildew of barley, identified it as Streptoverticillium rimofaciens. On agar media the antibiotic, which was named mildiomycin, was only weakly active against most fungi and bacteria tested. However, it inhibited some Mycobacterium and Rhodotorula, and it showed excellent control of powdery mildew of barley plants in greenhouse tests at concentrations between 31.2 and 62.5 ppm. Rhodotorula rubra IFO 0907 was selected as the test organism for in vitro assay of mildiomycin.  (+info)

Isolation and characterization of mildiomycin, a new nucleoside antibiotic. (59/82)

A new antibiotic mildiomycin, strongly active against powdery mildew, was isolated from the culture filtrate of Streptoverticillium rimofaciens B-98891. It is a water-soluble basic antibiotic and was purified by ion-exchange and adsorption chromatography. The molecular formula of the purified compound was determined to be C19H30N8O9(H2O) from physical and chemical data. The UV and NMR spectra suggested that this antibiotic is a nucleoside. On acidic hydrolysis it gave 5-hydroxymethyl cytosine which has not previously been found in nucleoside antibiotics.  (+info)

New antibiotics, carbazomycins A and B. III. Taxonomy and biosynthesis. (60/82)

The carbazomycin-producing microorganism, strain H 1051-MY 10, was determined to a strain of Streptoverticillium ehimense. Biosynthesis of carbazomycin B was studied using 14C-labeled and 13C-enriched precursors in combination with 13C NMR spectroscopy. The C-2 carbon of [2-13C]trytophan was shown to be involved at the C-3 carbon in carbazomycin B and both carbons of [1,2-13C]acetate at the C-1 and C-10 moiety of the antibiotic. [CH3-13C]Methionine was involved at the methoxyl group but not at the methyl group on the C-2 carbon of the antibiotic. Neither of the labeled carbons, [1-14C]tryptophan nor [2,3-13C]propionic acid, was detected in the antibiotic, and a progenitor of the C-2 and C-11 moiety of the antibiotic has not been determined.  (+info)

Taxonomy of the antibiotic Bu-2313-producing organism. Microtetraspora caesia sp. nov. (61/82)

An aerobic actinomycete strain isolated from an Indian soil sample and designated No. E864-61 was found to produce in submerged fermentation a new antibiotic complex, Bu-2313 (components A and B). Strain E864-61 forms single, pairs or chains of three to eight spores on the aerial mycelium and its aerial mass color is grayish blue-green. The cell wall of strain E864-61 contains meso-diaminopimelic acid and galactose. Strain E864-61 has been classified as a new species of the genus Microtetraspora and designated as Microtetraspora caesia sp. nov.  (+info)

Numerical classification of sporoactinomycetes containing meso-diaminopimelic acid in the cell wall. (62/82)

One hundred and thirty actinomycetes representing 19 genera and 50 species were compared in a numerical phenetic survey using 108 unit characters. Data were examined using the simple matching (SSM), Jaccard (SJ) and pattern (DP) coefficients and clustering was achieved using both the single and unweighted pair group average algorithms. Cluster composition was barely affected by the statistics used or by test error, estimated at 2.1%. Over 80% of the strains were assigned to 2 clusters containing between two and 25 organisms. Most of the clusters were distinct and homogeneous though two were divided into subclusters. Some of the clusters and subclusters were equated with the established taxa Actinomadura madurae, Actinomadura pelletieri, Dermatophilus congolensis, Geodermatophilus obscurus, Microbispora spp., Micromonospora spp., Micropolyspora brevicatena, Micropolyspora faeni, Nocardia spp., Nocardiopsis (Actinomadura) dassonvillei, Planobispora spp., Planomonospora spp., Saccharomonospora viridis, Streptomyces somaliensis, Thermoactinomyces candidus, Thermoactinomyces dichotomica, Thermoactinomyces sacchari, Thermoactinomyces vulgaris and "Thermomonospora fusca'. The numerical data, together with results from previous chemical and genetical studies, provide sufficient evidence for the transfer of Micropolyspora brevicatena to Nocardia as Nocardia brevicatena comb. nov.  (+info)

Hybrid biosynthesis of derivatives of protylonolide and M-4365 by macrolide-producing microorganisms. (63/82)

Biotransformation of a macrolide antibiotic and a related compound was studied using various macrolide-producing microorganisms grown in the presence of cerulenin, an inhibitor of de novo synthesis of the aglycone moiety. Protylonolide (1) was transformed into 5-O-(4'-O-propionylmycarosyl)protylonolide (2) by a leucomycin-producing strain, Streptoverticillium kitasatoensis KA-429. M-4365 G2 (3) was bioconverted into M-4365 G3 (4), 9-dihydro M-4365 G3 (5), 3-O-acetyl M-4365 G3 (6) and 3-O-acetyl-9-dihydro M-4365 G3 (7) by a spiramycin-producing strain, Streptomyces ambofaciens KA-1028. Forosaminylated derivatives of M-4365 G2 were not obtained using this microorganism. M-4365 G2 was converted into 3-O-acetyl M-4365 G2 (8) by Stv. kitasatoensis strain KA-429 and a carbomycin-producing strain, S. thermotolerans KA-442. These results suggest that the substrate specificity of mycaminose- and forosamine-binding enzymes is high in Stv. kitasatoensis and S. ambofaciens, respectively, while that of the 3-hydroxyl acylating enzyme and mycarose-binding enzyme is low in these microorganisms. The bioconversion products showed lower antibacterial and antimycoplasmal activities than those of M-4365 G2.  (+info)

Molecular cloning of the gene for microbial transglutaminase from Streptoverticillium and its expression in Streptomyces lividans. (64/82)

The microbial transglutaminase (TGase)-producing strains S-8112 [Agric. Biol. Chem., 53, 2613-2617 (1989)] was identified as a variant of Streptoverticillium mobaraense. We amplified a partial gene fragment by polymerase chain reaction (PCR) using oligonucleotides synthesized from the amino acid sequence of TGase, and cloned the gene for TGase using the PCR amplified fragment as a probe. The gene encoded a precursor of TGase consisting of 406 amino acid residues, which comprised the prepro region of 75 amino acid residues and the mature region of 331 amino acid residues. We expressed the TGase gene in Streptomyces lividans under a tyrosinase promoter, and found an active and mature recombinant enzyme, indicating the processing of the gene product.  (+info)