Recycling of cooking oil fume condensate for the production of rhamnolipids by Pseudomonas aeruginosa WB505.

Rhamnolipids (RLs) are anionic biosurfactants with great application potential. This study explored the possibility of producing RLs from cooking oil fume condensates (COFCs) collected from range hoods. A mutant of Pseudomonas aeruginosa AB93066 was obtained and used to produce RLs from COFCs as a substrate. RL yields in a 7-L fermenter reached 12.3 g/L, and MALDI-TOF MS showed that Rha2-C10-C10 and Rha-C10-C10 are the most abundant (39.6% and 26.4%, respectively) RL components. The critical micellar concentration (CMC) of the RLs was 45.0 mg/L and the surface tension of water decreased from 60.5 to 25.3 mN/m. Using six kinds of common hydrocarbons as indices, the emulsification coefficients of the RLs obtained were found to exceed 60%; in particular, the emulsification coefficient for benzene was 80.3%. COFCs provide an inexpensive alternative as a substrate for RL production, and the synthetic process is relatively harmless and economical.