RESUMEN
Target screening of natural immunosuppressors resulted in isolation of a strain of Streptomyces griseolus (No. 182) producing a complex of antifungal antibiotics. The strain proved to be an aerobe with the growth temperature of 26 to 28 degrees C. Morphological features and physiological properties of the strain were studied. Scanning electron microscopy revealed smooth, oval spores 1.10-1.25 mu in size. The findings showed that the strain belonged to Streptomyces griseolus. Unlike the previously described organisms producing the oligomycin complex the new strain formed straight or twisted sporophores and did not produce melanoid pigment or soluble pigment when grown on the Gauze mineral agar medium No. 1. The procedures for biosynthesis and chemical recovery of the antibiotic complex from the mycelium are described. The complex was shown to include 3 components at a ratio of 80:15:5 identified as oligomycins A, B and C respectively. The oligomycin complex was highly active against Aspergillus niger 137, Tolypocladium inflatum, Fusarium ocsisporum, Curvularia lunata 645 and Trichoderma alba F-32 (MIC 0.1-1.0 mcg/ml). The activity against yeast and bacterial cultures was observed only when the doses were higher than 100 mcg/ml.
Asunto(s)
Antifúngicos/biosíntesis , Oligomicinas/biosíntesis , Streptomyces , Antifúngicos/farmacología , Fermentación , Microscopía Electrónica , Oligomicinas/farmacología , Streptomyces/clasificación , Streptomyces/aislamiento & purificación , Streptomyces/metabolismoRESUMEN
In the programme for screening antibiotics with antifungal and immunosuppressing activity a culture of Streptomyces griseolus 182 was isolated. The culture produced a complex of oligomycin structure antibiotics. Individual components of the complex were isolated by HPLC. The complex was shown to contain three components at a ratio of 80:15:5. The findings were compared with the physico-chemical characteristics of the described antibiotics. On the basis of the analysis it was concluded that fraction 2 of the antibiotic complex 182 could be oligomycin A. A detailed comparative investigation of oligomycin A and component 2 with HPLC, FMR, IR spectroscopy and mass spectrometry revealed their identity. The other two components were shown to be oligomycins B and C.