Studies on bioemulsifier production by Acinetobacter strains isolated from healthy human skin

In recent years, interest has been growing in the search for novel bioemulsifiers. Many bacterial genera including Acinetobacter have been reported to produce bioemulsifiers. The present study aims to screen Acinetobacter isolates from healthy human skin for bioemulsifier production.

Acinetobacter junii SC14 produced maximum bioemulsifier in the presence of almond oil during stationary growth phase at 37 degrees C and pH 7.2. Partially purified, nondialysable bioemulsifier from SC14 was a proteoglycan. The protein and polysaccharide fractions resulted in 95.2% reconstitution of the emulsification activity. The role of esterase in the release of cell-bound emulsifier and the contribution of capsular polysaccharide to the emulsification activity were observed.

Acinetobacter strains from human skin exhibited better emulsification activity than that by burn wound or soil isolates, owing to the inherent differences in chemical microenvironment of their habitats.

Investigation of skin commensals, especially acinetobacters, would lead to the discovery of novel bioemulsifiers with interesting properties. Attempts of screening and strain improvement directed towards skin commensals will open up new avenues for strains producing bioemulsifier on a commercial scale.