摘要：A previously characterized biosurfactant-producing Lactobacillus plantarum KCA-1 isolated from the vagina of a healthy premenopausal woman was used in this study. Lactobacillus plantarum KCA-1 was tested for survival in different concentrations (0, 0.05, 0. 1, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5 and 4.0) of porcine and oxgall bile extract, incubated at 37°C for 48 h. Acid tolerance of the culture was studied by inoculating the organism (105CFU mL-1) in de Man Rogas Sharpe (MRS) broth at different pH values adjusted with HCl and incubated at 37°C for 48 h. Lactobacillus plantarum strain KCA-1 that produced biosurfactant needed for preventing adhesion of pathogens was tolerant to oxgall bile. There was an increase of 5 log cycles from the initial bacterial inocula (1x105cfu mL-1) to 1x1010cfu mL-1 at 0.05 and 0.1% concentrations of oxgall bile and 4 log cycle increase (1x109cfu mL-1) at 0.5% oxgall concentration. There was a consistent reduction of 1 log cycle of every 0.5% increase of the oxgall for tested concentrations (0.5 to 4.0%). In addition, Lactobacillus plantarum KCA-1 was tolerant at pH 2.5 for 48 h of incubation as there was 2.3 to 3.8 increase in the log cycles. There was a corresponding increase in the number of cells from 1x105 CFU to 1x109 CFU mL-1 at pH 4.5. The tested potential probiotic strain Lactobacillus plantarum KCA-1 exhibited a satisfactory degree of acid and bile tolerance. The findings suggests that the strain may be a promising candidate for use as a dietary adjunct, but more studies are needed.
