Rhamnolipid production from waste cooking oil by a newly isolated thermo- and salt-tolerant Pseudomonas aeruginosa GH01.

Biological treatment has become a promising approach for the efficient remediation of WCO. Identifying effective oil-degrading microorganisms is critical for optimizing these processes. This study focuses on isolating thermo- and salt-tolerant microbes capable of utilizing WCO as a carbon source for the production of high-value compounds. A newly isolated strain of Pseudomonas aeruginosa GH01 demonstrated exceptional degradation of over 92% of WCO at a concentration of 22 g/L within 5 days, producing 1011.2 mg/L of rhamnolipids. Notably, P. aeruginosa GH01 exhibited tolerance to NaCl concentrations up to 40 g/L and grew optimally at 45 °C, which is higher than that of most other P. aeruginosa strains. The strain also secreted thermotolerant lipases, with a half-life (T) of 75 °C for 15 min. These characteristics make P. aeruginosa GH01 a promising candidate for the bioremediation of WCO and the production of valuable biosurfactants like rhamnolipids. The ability to thrive in high salt and temperature environments also suggests its potential for industrial-scale applications, particularly in the WCO biodegradation and biosurfactant production industries.