Abstract
Lactobacillus casei f1, L. paracasei f2 and L. paracasei f3 with lipolytic activity were isolated and identified from vinasses according to the morphological-physiological properties detection and 16S rDNA analysis. These three strains showed obvious lipase activities to olive oil and L. casei f1 performed highest enzyme activity of 17.8 U/mL. L. casei f1, L. paracasei f2 and L. paracasei f3 could lipolyze the blending oils, peanut oil and sesame oil with diverse degrading rates. The degrading rates to the preferred oils, L. casei f1 to blending oils, L. paracasei f2 to peanut oil and L. paracasei f3 to sesame oil, were 21.2%, 27.3% and 39.6%, respectively. The corresponding oil degrading rates increased as the cell growth and the highest degrading rates were obtained at the stationary phase with the viable count more than 7.5 LogCFU/mL. By GC-MS analysis, L. casei f1, L. paracasei f2 and L. paracasei f3 performed diverse lipolytic capacities to the 12 kinds of fat acids and all of them preferred to hydrolyze the linoleic acid with the degrading rate of 49.11%, 31.83% and 64.44%, respectively. These three strains showed considerable probiotic properties, displaying higher than 106 CFU/mL desirable viable count though the simulated gastrointestinal tract, as well as inhibiting six indicator bacteria. These results suggested that the three isolated strains could be considered as novel probiotic candidates and applied in the food industry.