Broad Spectrum Antifungal Activity and Anticancer Potential of Secondary Metabolites from Cave Soil Streptomyces sp. strain YC69

Abstract

Cancer is one of the fatal diseases and has high mortality worldwide. The major drawback with the cure is the side effects from the chemotherapeutic agents, and there is an urgent need for an alternative. Actinomycetes from cave soil were isolated, and the crude extract obtained from the potent isolate was analyzed with GC-MS and HPTLC to identify bioactive metabolites. The crude extract was examined for in-vitro antimicrobial and antifungal activity on plant pathogens. The isolate Streptomyces sp. strain YC69 exhibited antagonistic activity and increased antimicrobial activity in a dose-dependent manner, with the highest inhibition observed in S. aureus. GC-MS revealed many bioactive compounds, and HPTLC depicted metabolite fingerprints. The antifungal activity exhibited a delayed lag phase in growth curve assay and distorted and collapsed cells of Fusarium oxysporum in SEM micrograph. The results from the current study suggest that the crude extract from Streptomyces sp. strain YC69 contains antimicrobial metabolites that can inhibit pathogenic microbes, which cause severe diseases in plants and humans. The MTT assay results conclude that further studies on purification may lead to the use of Streptomyces sp. strain YC69 as a source for anti-oncogenic compounds.