Several strains of P. acidilactici isolated from the intestine of healthy dairy cows and characterized using methods similar to those used in the present study were found to inhibit Escherichia coli. [37]. The authors reported that P. acidilactici was resistant to acid and bile salts, indicting the ability to survive and colonize in the intestine. In the present study, we found that Kp10 (P. acidilactici) was active against the pathogen L. monocytogenes. It is interesting

to note that P. acidilactici from two different agricultural sources (intestine of dairy cows and a traditional milk product) showed promising prophylactic properties. We found that the BLIS from Kp10 (P. acidilactici) was stable in a wide range of pH (2–9),

suggesting that its antimicrobial activity was not due to the pH of the cell-free supernatant. The reduced activity at high pH was probably due to denaturation of the protein. A similar AZD6738 result was also observed for an antimicrobial compound produced by Lactococcus lactis, which was active at the pH range 2 to 10 and completely inactivated at pH 12 [38]. Since bacteriocins are proteinaceous substances, they must be sensitive to at least one proteolytic buy AZD4547 enzyme [39]. Therefore, bacteriocins can be identified in part by exposure to proteolytic enzymes [40]. We found proteolytic enzyme treatment reduced the activity of the antimicrobial compound secreted by Kp10 (P. acidilactici). However, activity was not reduced by catalase, indicating that H2O2 was not responsible for microbial inhibition, or α-amylase activity, indicating that the compound was not glycosylated, which is characteristic of most bacteriocins [41]. Complete www.selleckchem.com/products/Trichostatin-A.html inactivation activity was observed after treatment with proteinase K and trypsin, in accordance with a report by Albano et al.[42] of pediocin PA-1 activity [43]. Treatment

with pepsin did not alter the antimicrobial activity of the BLIS in this study; however, proteolytic enzymes do not always reduce the antimicrobial activity of a bacteriocin [44]. Stability in the presence of a proteolytic enzyme could be due to unusual amino acids in the bacteriocin structure or cyclic N-terminal or C-terminal protected peptides [45]. We conclude that isolate Kp10 (P. acidilactici) is a potential probiotic that may exert beneficial Baf-A1 research buy positive effects on intestinal flora, because the strain is tolerant of bile salts (0.3%) and acidic conditions (pH 3). To better understand its potential as a probiotic, future studies are needed to characterize the interactions of this P. acidilactici strain to the intestinal mucosal epithelium. Methods Isolation of lactic acid bacteria Fresh curds (three varieties), dried curds (four varieties), ghara (one variety), and fermented cocoa beans were obtained from family-owned businesses in rural areas of Malaysia and Iran. Ghara is a traditional flavor enhancer that is popular in northern Iran.