RESUMEN
<p><b>OBJECTIVE</b>To isolate and indentify the promising antimicrobial metabolite producing Streptomyces strains from marine sediment samples from Andrapradesh coast of India.</p><p><b>METHODS</b>Antagonistic actinomycetes were isolated by starch casein agar medium and modified nutrient agar medium with 1% glucose used as a base for primary screening. Significant antimicrobial metabolite producing strains were selected and identified by using biochemical and 16S rDNA level. Minimum inhibitory concentrations of the organic extracts were done by using broth micro dilution method.</p><p><b>RESULTS</b>Among the 210 actinomycetes, 64.3% exhibited activity against Gram positive bacteria, 48.5 % showed activity towards Gram negative bacteria, 38.8% exhibited both Gram positive and negative bacteria and 80.85 % isolates revealed significant antifungal activity. However, five isolates AP-5, AP-18, AP-41 and AP-70 showed significant antimicrobial activity. The analysis of cell wall hydrolysates showed the presence of LL-diaminopimelic acid and glycine in all the isolates. Sequencing analysis indicated that the isolates shared 98.5%-99.8% sequence identity to the 16S rDNA gene sequences of the Streptomyces taxons. The antimicrobial substances were extracted using hexane and ethyl acetate from spent medium in which strains were cultivated at 30°Cfor five days. The antimicrobial activity was assessed using broth micro dilution technique. Each of the culture extracts from these five strains showed a typical polyene-like property. The lowest minimum inhibitory concentrations of ethyl acetate extracts against Escherichia coli and Curvularia lunata were 67.5 and 125.0 µg/mL, respectively.</p><p><b>CONCLUSIONS</b>It can be concluded that hexane and ethyl acetate soluble extracellular products of novel isolates are effective against pathogenic bacteria and fungi.</p>
Asunto(s)
Actinobacteria , Química , Clasificación , Genética , Antibacterianos , Química , Farmacología , Antiinfecciosos , Química , Farmacología , Antifúngicos , Química , Farmacología , Bahías , Mezclas Complejas , Química , Farmacología , Sedimentos Geológicos , Microbiología , India , Pruebas de Sensibilidad Microbiana , Datos de Secuencia Molecular , Filogenia , Polienos , Química , Farmacología , ARN Ribosómico 16S , GenéticaRESUMEN
Objective To investigate the antibacterial and antifungal metabolites from the fermentation broth of Streptomyces sp.M095 and classify the strain M095.Methods The structure was evaluated by spectral(ESI-MS,EI-MS,~(1)H-NMR,~(13)C-NMR and APTNMR) analysis.And the strain M095 was analysed with the characteristic of the culture and modality and the sequence of 16S rDNA.Results An antibiotic was found to have the remarkable activity to Staphylococcus aureus and filaceous fungi Mucor miehei(T 284).And its structure was identified as holomycin.The strain M095 was classified as maybe a variety belongs to Streptomyces Globisporus group.Conclusion The activity of holomycin to fungi was reported for the first time in this paper.The antimicrobial spectrum of holomycin was broadened.