Effect of combined nutrients on biosurfactant produced by Pseudomonas putida.

This work investigated biosurfactant production by Pseudomonas putida in combined C/P, C/Ninorganic, C/Fe, C/Mg nutrient ratios and peptone concentration. Analysis of the 2(5-1) fractional factorial experimental design showed that only the C/Fe ratio had a significant (p<0.02) effect on biosurfactant production. The highest amount of biosurfactant was obtained at low C/Fe ratios, but net surface tension did not show significant differences. In addition, low amounts of peptone and the C/P-C/Mg nutrient ratios interaction significantly (p < 0.05) enhanced the biomass produced by P. putida. Analysis of biosurfactant by gas chromatography (GC) showed that the hydrophilic fraction was composed by rhamnose and the hydrophobic fraction, mainly by palmitic (C16), stearic (C18:0), oleic (C18:1) and linoleic (C18:2) fatty acids.