Optimization of Rhamnolipid Production by P. aeruginosa Isolate P6

Abstract

© 2016, AOCS. Rhamnolipids are interesting microbial surfactants having great industrial importance. However, the main obstacles towards an economic production of rhamnolipids are low productivity and high raw-material costs. Therefore, this study aimed at optimization of the culture media as well as culture conditions using response surface methodology for maximum rhamnolipid production by Pseudomonas aeruginosa isolate P6, a promising rhamnolipid-producing isolate. The optimum medium for maximum rhamnolipid production was found to be a mineral salts medium with glycerol 2 % v/v as the carbon source. The optimum cultivation conditions using response surface methodology were found to be an incubation temperature of 30 °C, an agitation rate of 250 rpm, an inoculum size of 5 % v/v and unlike most studies, an initial pH of 7.5. The resulting model predicted data points that corresponded well to the experimental values. Optimization resulted in a threefold increase in rhamnolipid production reaching 7.54 g/L. The data are potentially useful for further industrial exploitation of rhamnolipid production by the studied isolate.