Bioactive compounds derived from Streptomyces sp. SA32: antibacterial activity, chemical profile, and their related genes

Abstract

Microbes which are resistant to drugs and antibiotics as well as multi-drug resistant (MDR) microbes have developed due to the improper use of antibiotics and led to explore the microbial isolates as the sources of new antibiotics or those with highly effective and stabile attack. Streptomyces sp. SA32 was selected to inhibit the growth of MDR bacteria Escherichia coli, Staphylococcus aureus, Klebsiella pneumonia, Pseudomonas aeruginosa, Enterobacter cloaceae, and Enterococcus sp. E. coli was sensitive to crude extracts of Streptomyces sp. SA32 at the concentration of 19 g.mL-1 with moderate strength against E. cloacae. The bioactive compounds analyzed using thin layer chromatography and phytochemical methods showed that the spot with Rf 0.63 and 0.68 was polyketide compound and that with Rf 0.74 was flavonoid compound. The bioautography assay on the TLC plate confirmed the absence of MDR bacterial growth on polyketide and flavonoid spots. The synthesis of antibacterial compounds was also confirmed by the successful analysis on both non-ribosomal peptide synthetase (NRPS) and polyketide synthase (PKS) gene sequences.