Formulation of medium for bactericide biosynthesis using wild type streptomyces sp

Abstract

© 2018, CI and CEQ. All rights reserved. The aim of this study was formulation of medium for the production of bactericide effective against Staphylococcus aureus and Escherichia coli using Streptomyces sp. isolated from the soil. Biosynthesis of antibacterial compounds was performed on media prepared in accordance with Box-Behnken design with three factors on three levels and three repetitions in the central point where the contents of the carbon source (10.0-50.0 g/L), soybean meal (5.0-25.0 g/L) and phosphates (0.5-2.5 g/L) were varied. Fructose, lactose, sucrose, starch and glycerol were used as carbon sources. Since the cultivation broths showed activity only against Staphylococcus aureus, the values of inhibition zone diameters for this microorganism were statistically processed using response surface methodology and desirability function approach in order to optimize relations of varied nutrients. Media with glucose were not used in these experiments, but the mathematical model defined in previous research was applied for optimization. The developed models predict that optimal concentrations of carbon source, soybean meal and phosphates are about 10.0, 5.0 and 0.5 g/L, respectively, except in the lactose-containing medium, where the optimal phosphate content is 0.9 g/L. Performing the bioprocess in optimal media, the maximum inhibition zone diameter against Staphylococcus aureus was formed by the medium with fructose (34.5 mm).