Isolation, characterization, and antimicrobial activity of Actinomycetes isolated from garden soil

Abstract

Five different strains of Actinomycetes were isolated from rhizosphere soil sample taken from Tulsi gardens of Kayathar, Tuticorin District. Heat treated Tulsi growing rhizosphere soil samples (Kayathar, Tuticorin District) were subjected to serial dilution and plated on starch casein medium, incubated at 37 °C for 7 - 14 days. The isolated strains were subjected to morphological, biochemical and cultural characterisation to study their spore morphology, asexual reproductive spores, substrate mycelial growth and enzyme degradation. Tests were performed as per International Streptomyces Project (ISP). Morphological and cultural characteristics showed that the strains AJ1, AJ2, AJ3, AJ4 and AJ5 belonged to the genus Actinomycete. The cultures showed substrate and aerial mycelial growth and also soluble pigments. Based on their morphology the isolates were subjected to antimicrobial activity against pathogens. Antimicrobial activity was performed against seven clinical isolates. AJ1 was found to show maximum activity against Klebsiella, S.typhi and Enterobacter whereas AJ5 was found to show inhibitory activity against Klebsiella.

Keywords

• actinomycetes
• morphology
• characterization
• antimicrobial activity