Simultaneous production of lipopeptide and rhamnolipid biosurfactants by Pseudomonas aeruginosa : A promising blend for biosurfactant-enhanced bioremediation

Oil contamination is an environmental issue worldwide, and bioremediation has emerged as a preferred strategy to address this challenge. One of the limiting factors in oil biodegradation is its bioavailability, which can be solved by the addition of tensioactive compounds. Given the increasing demand for environmentally friendly surfactants, this study aimed to obtain cell-free biosurfactant extracts as additives in surfactant enhanced remediation (SER) protocols. Diesel-degrading, surfactant-producing strains were isolated to obtain biosurfactant extracts with minimal post-production purification cost. The most promising extracts were tested for SER assays using diesel-contaminated microcosms. One of these showed a significant enhancement in diesel degradation compared with the controls. This extract was obtained from a Pseudomonas aeruginosa strain and consisted of a blend of rhamnolipids and lipopeptides. This is the first work reporting the co-production of both kinds of surfactants by a P. aeruginosa strain and its potential for application in surfactant-enhanced bioremediation strategies.