Optimization Of Culture And Extraction Conditions For Antimicrobial Activity Of Streptomyces C24 Isolated From Con Dao Island

Abstract

Streptomyces C24 was one of the most promising strains among 25 strains isolated from Con Dao Island in terms of antibiotic production. We tested the antimicrobial activity of Streptomyces C24 cultured in several original media and extracted with different solvents, then selected the most suitable solvent for further use and the most potent medium to go on the optimization step. To optimize for the improved antimicrobial activity, Streptomyces C24 was cultured in different media with various concentrations of carbohydrates and collected at different culture times. ISP 2 medium was proved to be effective in the production of the antibiotics and was chosen for further optimization. Replacing dextrose by starch in ISP 2 medium as the carbon source at the concentration of 10 gL-1 and incubating for 120 to 144 hours, Streptomyces C24 performed a wide range of inhibition of various microbes. The result proved that the suitable medium and harvesting time are essential factors needed to explore potentials from these bacteria.