Isolation, Production and Purification of Antibiotics Isolation from Microbes from Soil

Abstract

A chemical compound acting against life is called antibiotics. The term “antibiotic” literally means “against life”. The term appeared as early as 1928 in the French microbiological literature as antibiosis. The phenomenon of antagonism between living organisms was frequently observed even since 1877, when Pasteur and Joubert noticed that aerobic bacteria antagonized the growth of Bacillus anthracis. However, the world in its present restrictive meaning, “a chemical substance derived from microorganisms, which has the capacity of inhibiting growth and even destroying other organisms in dilute solutions” was introduced by Selman and Waksman in 1942. Screening of antibiotics has been widely performed for about last 50 years and new antibiotics are still being found. In screening of new antibiotics, new approaches are required and following three factors must be considered i.e. detection of antibiotic producing microorganisms, selection of producing microorganisms and cultivation methods. These are closely related to each other, and their efficient combination is essential for successful screening of an antibiotic. The goal of the project was to isolate the antibiotic producing microbe from soil and production and purification of antibiotics. To achieve the goal soil sample from the rhizosphere of tulsi was diluted by serial dilution method and plated on nutrient agar medium. Primary screening was done to check the zone of inhibitions. Strain from the zone of inhibition was picked up and pure culture was made by streaking method on plate: Crowded Plate Technique’ and slants for further analysis. From crowded plate, 04 microbial strains were isolated and tested for antibiotic production. The purified antibiotic showed significant and potent antibiotic activity. Efforts to establish the complete structure of the antibiotic is in progress Optimization of the parameters of the bioreactors and medium formulation helped in increasing productivity of the product in laboratory scale and may help in production scale. Based on the above experimental study, we have arrived the following conclusions:- The strain A-4 was found to be having better antimicrobial activity in comparison with other soil isolates, which have been investigated. The morphological, biochemical studies of strain A-4 showed the characteristic features of the family Enterobacteriaceae The growth medium and parameters were optimized formaximum production of antibiotic from A-4