DefinePK

Abstract

Biosurfactants are eco-friendly surface-active compounds with broad industrial applications, yet their commercial production is often hindered by low yields and high costs. This study focused on optimizing the physical and biochemical factors affecting biosurfactant production using the One Variable At a Time (OVAT) approach. Two biosurfactant-producing bacterial isolates—Achromobacter xylosoxidans (P5c) and Pseudomonas aeruginosa (P11)—were subjected to a range of culture conditions to evaluate the impact of different carbon sources, nitrogen sources, temperatures, pH levels, and salt concentrations on biosurfactant yield, emulsification activity (%E24), surface tension (ST), and dry cell biomass (DCBM).
Among the tested parameters, glucose and glycerol emerged as the most favorable carbon sources, while ammonium nitrate supported the highest biosurfactant production among nitrogen sources. Optimal biosurfactant yields were observed at 35 °C and pH 7.0 for both isolates. Salt concentrations between 1% and 2% promoted the best microbial growth and biosurfactant activity, with P. aeruginosa showing higher salt tolerance than A. xylosoxidans. Emulsification activity and surface tension measurements corroborated the biosurfactant productivity under optimized conditions. This study demonstrated that targeted adjustment of key environmental and nutritional factors can significantly enhance biosurfactant production.