ANTIMICROBIAL ACTIVITIES OF STREPTOMYCES SPECIES ISOLATED FROM TERMITARIUM AND GRASSLAND SOILS

Abstract

Antimicrobial activities of metabolites of Streptomyces species from termitarium and grassland soils were studied against some pathogenic microorganisms. Streptomyces species were isolated from the above soil samples by streak plate technique. The active metabolite was extracted using chloroform. Optimization of the extracted metabolites was done at different pH, carbon sources and metal salts. Purification of the extract was performed using column and thin layer chromatographic techniques. The metabolites (non-purified and purified) produced were screened for antimicrobial activities against some pathogenic bacteria and fungi using agar well diffusion method. Antibiotic sensitivity test was also carried out. The Streptomyces species isolated from termitarium are Streptomyces griseoflavus, Streptomyces xanthophaeus, Streptomyces viridoflavus, Streptomyces galtieri, Streptomyces albidoflavus and Streptomyces microflavus. Also, those isolated from grassland soil are Streptomyces rimosus, Streptomyces albus, Streptomyces fumosus, Streptomyces riseoflavus, Streptomyces spiraiis, Streptomyces flavogriseus and Streptomyces aureofaciens. During the primary screening, six Streptomyces species, Streptomyces rimosus, Streptomyces flavogriseus, Streptomyces albus, Streptomyces riseoflavus, Streptomyces griseoflavus, Streptomyces xanthophaeus showed inhibitory effect against some test pathogenic bacteria and fungi. The purified metabolite of Streptomyces albus showed high inhibitory effect on Serratia marcescens and Pseudomonas aeruginosa while Streptomyces rimosus showed high inhibitory effect on Klebsiella pneumoniae. Also, Streptomyces riseoflavus showed high inhibitory effect on Staphylococcus aureus. On the antibiotic sensitivity test, Pefloxacin and Gentamycin showed the highest and least inhibitory effect against all the pathogenic bacteria respectively. Partially purified metabolites of Streptomyces flavogriseus compared favourably with known commercial drugs. Streptomyces flavogriseus from grassland area should be exploited in production of antibiotics for treatment of dysentery caused by Shigella and possibly also methicillin resistant Staphylococcus aureus