Optimization of culture conditions of probiotic bifidobacteria for maximal adhesion to hexadecane

Culture growth conditions were optimized for adhesion to hexadecane of the probiotic Bifidobacterium bifidum HI 39 and HI 48. Among three growth media used, MILS lactose broth was the best medium to obtain maximum cell adhesion, followed by MRS and TPY lactose broth for B. bifidum HI 39 and HI 48. Increasing the incubation time from 6 to 18 h resulted in a gradual increase in percentage adhesion at 37degreesC of both organisms in MILS, MRS and TPY media. Thereafter, incubation up to 48 h showed a marked reduction in adhesion of B. bifidum HI 39 and B. bifidum HI 48. When the test cultures were grown at pH values from 5.0 to 8.0 in MILS lactose broth at 37degreesC for 18 h, there was a gradual enhancement in cell adhesion up to pH 7.0; but higher pH values retarded the bacterial adhesion. The study showed that the optimum conditions for adhesion to hexadecane of the selected bifidobacterial strains were pH 7.0 and incubation at 37degreesC for 18 h in MILS broth.