Production of antifungal antibiotics polyaxonic by Streptomyces cacaoi var ascensus NRC-19

ABSTRACT

Antifungal antibiotics polyoxins have been obtained from the culture of Streptomyces sp. NRC-19 isolated from agricultural Egyptian soil. The producing microorganism was identified as Streptomyces cacaoi var. asoensis NRC-19 on the basis of taxonomic studies. The production of antibiotic was carried out in jar fermentor 7L bench scale. The antibiotic complex was separated with activated charcoal from the filtrated broth at pH 2 and purified by cellulose column chromatography. Two related active substances were obtained from the column chromatography designated as polyoxins A and B with paper chromatography. The crude antibiotics exhibit the behavior of Rugulosin and Aternariol antibiotics on the chromatographies of Betina technique. On the other hand, the crude and pure antibiotic substances were effective against some fungi such as Alternaria spp. and Fusarium oxysporum at a concentration of 5 ug/ml