Screening for ability of locally isolates Leuconostoc spp. to produce biosurfactant and determination of optimum condition for its production

Abstract

Fifteen samples of raw milk and yogurt were used to isolate Leuconostoc spp. ,Twenty eight Leuconostoc spp.were isolated. All isolates were tested for biosurfactant production , Producer isolates were then subjected to the biochemical examination and Vitek 2 system for identification to the species . Eleven of biosurfactantproducer isolates were identified from 28 Leuconostoc isolates. They are distributed as Leuconostoc mesenteroide sssp cremoris . Surface activity of Leuconostoc mesenteroides ssp cremor is supernatants were studied .The optimal conditions of biosurfactant production included growing at different temperatures; different pH, different incubation periods, aeration and inoculum ratio were also studied. The results showed that surface activity of supernatant was differed according to isolate, with oil displacement diameter 4-7 mm. Anaerobic and aerobic conditions for 24 hours at30o C and pH 6 and 2% inoculum were fitting to biosurfactant production.