ANTIBIOTIC PRODUCTION BY RHIZOSPHERIC SOIL MICROFLORA – A REVIEW

The rhizosphere represents the thin layer of soil surrounding plant roots and the soil occupied by the roots, supports large active groups of microorganisms. The vast organic compounds (amino acids, sugars etc.) secreted by plant roots in the rhizosphere provide a food source for microorganisms increasing microbial biomass and their activity in the rhizosphere. Antibiotics are antimicrobial compounds produced by living microorganism as secondary metabolites. These compounds are used therapeutically and sometimes prophylactically in the control of infectious diseases. The isolation of antibiotics from microorganisms is relatively easy as compared to chemical synthesis of antimicrobial agents. The isolation of antibiotics from microorganisms improved the discovery of novel antibiotics that could act as better chemotherapeutic agents. With the increased population pressure, costs and side effects and the development of resistance of pathogens to drugs for infectious diseases, there is an urgent need to explore microbes for development of new antimicrobial metabolites. As microorganisms grow in unique and extreme habitats, they may have the capability to produce unique and unusual metabolites. So rhizospheric soil gives an excellent option as a source for search of some new alternative medicines. This review highlights the recent developments in the production of antimicrobial compounds from rhizospheric soil microflora.