Cholesterol removal from media by Lactobacillus plantarum ST-III

The objective of this study was to determine the interaction between the initial pH of broth cultures, heat treatment of cells and cholesterol removal from media by Lactobacillus plantarum ST-square. The MRS-THIO broths (100 mu g/mL cholesterol) were previously adjusted to the different levels of pH. The heat-killed cells and the unheated-killed cells were suspended in MRS-THIO broth (100 mu g/mL cholesterol) and 0.05M phosphate buffer (100 mu g/mL cholesterol), respectively. After incubation, the cultures were assayed for cholic acid and cholesterol. The results indicated that the initial pH of broth cultures affected bile salt deconjugation and cholesterol removal from media (P<0.05). The ability to remove cholesterol was also observed in the heat-killed cells of L. plantarum ST-III. However, the amount of cholesterol removed by the cells during growth was significantly higher than that removed by the heat-killed cells (P<0.05). Thus, the strain of Lactobacillus plantarum ST-III has the ability to remove cholesterol from media independently of whether cells are viable.