RESUMO
Background: A glycolipopeptide biosurfactant produced by Pseudomonas aeruginosa strain IKW1 reduced the surface tension of fermentation broth from 71.31 to 24.62 dynes/cm at a critical micelle concentration of 20.80 mg/L. The compound proved suitable for applications in emulsion stabilization in food, as well as in cosmetic and pharmaceutical formulations
Methods: In the present study, Plackett-Burman design [PBD] and response surface method [RSM] were employed to screen and optimize concentrations of trace nutrients in the fermentation medium, to increase surfactant yield
Results: The PBD selected 5 significant trace nutrients out of the 12 screened. The RSM, on the other hand, resulted in the production of 84.44 g glycolipopeptide/L in the optimized medium containing 1.25 mg/L nickel, 0.125 mg/L zinc, 0.075 mg/L iron, 0.0104 mg/L boron, and 0.025 mg/L copper
Conclusion: Significant second-order quadratic models for biomass [P<0.05; adjusted R2=94.29%] and biosurfactant [R2=99.44%] responses suggest excellent goodness-of-fit of the models. However, their respective non-significant lack-of-fit [Biomass: F=1.28; P=0.418; Biosurfactant: F=1.20; P=0.446] test results indicate their adequacy to explain data variations in the experimental region. The glycolipopeptide is recommended for the formulation of inexpensive pharmaceutical products that require surface-active compounds