Harmonizing rhamnolipid biosurfactant production by halophilic Pseudomonas aeruginosa Pa84 by applying response surface methodology

Abstract

Biosurfactants are gaining attention due to their biobased nature, including reduced toxicity and enhanced biocompatibility. This research work investigates the characteristics of the biosurfactant extracted from the halophilic strain Pa84 of Pseudomonas aeruginosa and optimizes its production using a statistical model. The identity of biosurfactant from P. aeruginosa strain Pa84 as rhamnolipid was determined by comparing the genomic sequences of strain Pa84 with high-yielding strains of P. aeruginosa that produce rhamnolipid, through Fourier transform infrared and liquid chromatography-mass spectrometer analyses, and by the presence of rhlA, rhlB, and rhlC genes in the genome of strain Pa84 that are responsible for the production of rhamnolipid. A methodical strategy using a time-course assessment and statistical software optimized the production of rhamnolipids. After optimization using central composite design-response surface methodology, the medium composition of 3.34 g/L of NH₄Cl, 1.03 g/L of NaCl, and 4 g/L of glycerol were chosen, yielding 7.48 ± 0.0217 g/L of biosurfactant. These findings will help in the development of effective and sustainable bioprocess that produce rhamnolipid biosurfactants, for use in a variety of sectors.