Investigation into Antimicrobial and Antiproliferative Effects of Secondary Metabolites of Lactobacillus saerimneri Novel Isolated from Vaginal Flora

Objectives: The aim of this study was to determine the quantitation of lactic acid, acetic acid and hydrogen peroxide of secondary metabolites produced by Lactobacillus saerimneri isolated from vaginal flora for the first time. Also, the antimicrobial effects of secondary metabolites against test microorganisms and their effects on the proliferation of HCT 116 Colon Cancer Cells were investigated. Materials and Methods: Isolate was identified by analyzing the 16S rRNA gene sequence. Quantities of lactic acid, acetic acid, and hydrogen peroxide were determined by HighPerformance Liquid Chromatography (HPLC). The antimicrobial effects were investigated using Agar Spot Method. In addition, the effects of the secondary metabolites on the proliferation of HCT 116 Colon Cancer Cells were tested. Results: It was determined that L. saerimneri isolate produced 3.303 μg/μL hydrogen peroxide, 3.288 μg/μL acetic acid and 0.252 μg/μL lactic acid. The secondary metabolites were found to be effective against Pseudomonas aeruginosa and Bacillus subtilis. Secondary u c r e ct d p roo f metabolites did not have any effect on the proliferation of HCT 116 Colon Cancer Cells at a concentration of 0.83% but decreased cell viability at doses ranging from 4.16% to 16.6% in a dose-dependent manner. Conclusion: Our study is of significance as its isolated L. saerimneri from human vaginal flora for the first time. The detection of the significant effects of isolate on some bacteria and on the proliferation of HCT 116 Colon Cancer Cells suggests that flora bacteria may be used as an alternative treatment option. Considering the HPLC results, lactic acid, acetic acid, and hydrogen peroxide may be responsible for these effects of secondary metabolites.