Abstract

ISOLATION, CHARACTERIZATION AND SCREENING OF ACTINOMYCETES FOR ANTIBACTERIAL ACTIVITY FROM THE SOIL OF GAZIPUR, BANGLADESH

Ashish Kumar Sarker, *Md. Anwarul Haque, Rishikesh, Drishti Rani Ghosh, Md. Anwar Ul Islam

ABSTRACT

The aim of this study was to isolate actinomycetes strains having antibacterial activity from soil samples collected from various places around Gazipur, Bangladesh. From four soil samples using Starchcasein- nitrate-agar medium, a total of eight actinomycetes strains were isolated in pure form. These strains were primarily screened for their antibacterial activity against a series of test bacteria. Five (62.5%) strains showed moderate to high antibacterial activity. Among them, due to the highest antibacterial activity, visibility of the metabolite as well as excellent growth properties, ASAR-5 strain was selected for morphological, cultural, physiological and biochemical studies and these studies strongly suggested that the isolate belonged to Streptomyces sp. The extract of metabolite from this potential strain was obtained by solvent extraction method using ethyl acetate. The extracts exhibited reasonably strong antibacterial activity against a series of Gram positive and Gram negative bacteria when compared with standard Kanamycin (30g/disc) disc. The zones of inhibition were observed between 14-21 mm. The minimum inhibitory concentration (MIC) of crude extracts was determined against four bacteria and the values were found in the range of 16 and 32 g/ml.

Keywords: Gazipur, Actinomycetes, Isolation, Characterization, Antibacterial activity, Metabolites.