Improvement of high-productive biosurfactant producers through ultraviolet mutation and genome shuffling

Biosurfactants have been widely considered as promising alternatives to chemical synthetic surfactants since they are effective, biodegradable and less toxic. Despite having these attractive advantages, compared with their synthetic counterparts the lack of powerful biosurfactant-producers has been a challenge in application. To help fill the gap, this study aimed at developing high-productive biosurfactant producers. Mutant M25 were developed from Rhodococcus through UV irradiation, which showed excellent results with a CMD of 225 and dispersing abilities competitive with the most commonly used chemical synthetic surfactant for oil dispersion (Corexit 9500A). GS43 was a recombinant improved from Halomonas by the recently developed Genome Shuffling method. GS43 exhibited 4 times more effective at the 10% Broth/Oil rate and GS43 was 100% greater than in the E24 wild type. GS43 also showed more stable results over a wide range of temperature (5 -70 ºC) and pH (1-12), as well as being salt-tolerant and higher emulsion effects with n-hexadecane, mineral oil, crude oil, toluene, dodecane, Iso-octane, olive and corn oil. Moreover, GS43 possessed both emulsifying and surfactant (27.3 mN/m) properties