Author(s): Aradhana Priyambada Bhuyan* and RNS. Yadav and R. Samanta
Antibiotics are the important secondary metabolites of almost all types of microbes. Soil microbes also produce antibiotics. The process of antibiotic production by microbes is known as antibiosis where the metabolic products of one organism directly inhibit or kill other pathogenic organisms. Northeastern region of India is well known for its biodiversity hotspot with so many unexplored economically important microorganisms. The aim of the current study is to detect the antimicrobial activity of soil isolates from Dibrugarh District, Assam, India. A total of 50 soil samples were collected from the selected areas of Dibrugarh district. 115 bacterial isolates showed potential antimicrobial activities, out of which 64 showed good antimicrobial activity, 31 showed low antibacterial activity and 21 showed antifungal activities against B. subtilis (MTCC 121), Pseudomonas arginosa (MTCC 4673), S. cerevisiae (MTCC 3090) and Candida albicans (MTCC 227), E.Coli (MTCC 40), Clostridium acetobutylicum (MTCC 11274), Enterococcus mutans (MTCC 3031), Streptococcus mutans (MTCC 497) .The most potent bacterial isolates with antimicrobial effects against the above mentioned standard strains were identified as Klebsiella pneumonia sp on the basis of biochemical tests as prescribed by Bergey’s manual of systematic bacteriology. These results indicate that the areas of Dibrugarh District soil microorganisms could be an interesting source of antibacterial and antifungal bioactive substances.