Bioprospecting of Streptomyces sp. MECO2 from stones of an ancient Egyptian tomb with promising antitrichophyton activity under optimized cultivation conditions
The present work was initiated by isolating terrestrial actinomycetes from the stones of one of the Egyptian ancient tombs where 127 pure actinomycetes isolates could be recovered. Ten of them were tested for their antimicrobial activities against Trichophyton mentagrophytes pathogen. The phenotypic features of the isolate with the highest activity were studied. Additionally the molecular characterization was carried out for the active isolate, where the PCR amplicons of the promising isolate were sequenced and aligned against the 16S rRNA of the Ribosomal Database Project. The high level of sequence similarity of the Streptomyces isolate No. 1 was to Streptomyces sp. MECO2 which has similarity (99%). Series of experiments were conducted to optimize the physiological and fermentation conditions allowing maximum activity of the selected organism. Relatively high antitricophyton activity was attained with cultivation medium composed of (g/l): glucose, 5; casein, 0.0075; KNO3, 0.05; NaCl, 2; K2HPO4, 6; MgSO4.7H2O, 0.05; CaCO3, 0.02 and FeSO4.7H20, 0.01; pH 7 adjusted using phosphate buffer, inoculums size 2ml/50ml medium and agitation rate of 200 rpm at 30°C for 9 days incubation. The mycelial cake ethylacetate extract was subjected to chromatographic fractionation followed by preliminary characterization to the most active fraction. © IDOSI Publications, 2013.
Saleh, A. M.; El-Refai, H. A.; Abdulla, H.; Hanna, A. G.; Hashem, Abdel Gawad M.; and El-Refai, A. H., "Bioprospecting of Streptomyces sp. MECO2 from stones of an ancient Egyptian tomb with promising antitrichophyton activity under optimized cultivation conditions" (2013). Pharmacy. 393.