Diversity and antibacterial activity of actinomycetes from wetland soil

Abstract

Diversity of soil actinomycetes isolated from various regions of a wetland was analysed. The strains were assigned under 11 genera according to their morphological and biochemical characteristics. They are: Nocardia , Pseudonocardia , Streptomyces , Micromonospora , Rhodococcus , Actinosynnema , Nocardiodes , Kitasatospora , Gordona , Intrasporangium and Streptoalloteichus . Around 55% of the identified strains are Nocardioform actinomycetes . Screening for their antibacterial activities revealed that 96% of the isolated strains showed different degrees of inhibition potential against 12 test pathogenic bacteria (including various serotypes of Salmonella , Vibrio cholerae , Bacillus subtilis and Escherichia coli ). Of these about 41% of strains showed antagonism towards Bacillus subtilis . The Nocardioform actinomycetes exhibited antibacterial activity against 9 out of 12 test organisms. The least antibacterial potential was exhibited by Gordona , Rhodococcus , Micromonospora and Kitasatospora . The isolated strains differed among themselves in their ability to decompose proteins and amino acids and also in enzyme production potential.