SCREENING, PARTIAL PURIFICATION AND CHARACTERIZATION OF ANTIMICROBIAL COMPOUND FROM STREPTOMYCES ROCHEI SJKS1 ISOLATED FROM THE SEASHORE SOIL OF DHANUSHKODI

Author(s): B. Kiran Sharma, M.D. Balakumaran, B. Kirthiga and S. Jagadeeswari

Abstract: Totality of 60 diverse Streptomyces colonies was isolated from soil samples acquired from 25 different geographical locations. Primary, secondary and tertiary screening methods were used to detect the isolates that possessed maximum antibacterial activity against both Gram positive and Gram-negative microorganisms. Solvent (ethyl acetate) extraction of metabolites of three best isolates was carried out followed by agar well diffusion assay. The potential isolate was morphologically, physiologically and biochemically characterized based on Bergey’s manual of determinative bacteriology and International Streptomyces Project (ISP). Molecular characterization by 16S rRNA sequencing revealed that the isolate was Streptomyces rochei SJKS 1. Minimum inhibitory concentration (MIC) of the solvent extract from the isolate against Staphylococcus aureus ATCC 9144 and Escherichia coli ATCC 25922 was recorded to be 260 μg on comparison with the standards. Synergistic studies revealed a positive synergism between the solvent extract and the commercial antibiotics when used in combination against the test microorganisms. The probable mechanism of antibacterial action of the active compound was elucidated by membrane leakage studies and the ethyl acetate extract was further analyzed by thin layer chromatography (Rf value 0.12). UV-visible spectroscopic studies of the bioactive compound displayed a maximum UV absorption at 221 nm, a characteristic similar to that of polyene antibiotics. FTIR studies of the extract further revealed the functional groups of the antimicrobial compound.

PAGES: 518-528  |  22 VIEWS  44 DOWNLOADS