Biosurfactant production by Pseudomonas aeruginosa WARP_W1: kinetics and structural elucidation of glycolipids

In this study, biosurfactant-producing bacterial isolates were screened and isolated from a hydrocarbon-rich automobile workshop, marine water, agarwood, and ayurvedic industrial waste. The efficient bacterial isolate Pseudomonas aeruginosa WARP_W1 reduced surface tension to 35.21 mN/m and emulsified 64.32% of olive oil. The biosurfactant production was attempted using different oil sources, with coconut oil producing 899.69 mg/L biosurfactant, which is 35.8% more than olive oil. Logistic kinetic models accurately predicted microbial growth rate (R² > 0.975) and biosurfactant production rate at 0.348h⁻¹ and 0.201h⁻¹, respectively. These data suggest that coconut oil could be a suitable substrate for biosurfactant. The physicochemical properties were also found to be efficient, with a low critical micelle concentration of 110.60 mg/L and a lowered surface tension of 26.99 mN/m in coconut oil. FTIR and NMR spectroscopy confirmed the glycolipid in the produced biosurfactant by showing rhamnolipid-like structural features. P. aeruginosa WARP_W1 is ideal for large-scale biosurfactant production because of its versatile utilization of carbon sources. This study provides the growth and product kinetic information on the substrate-specific production of biosurfactants.