Characterization of Plantaricin Genes and Lactic Acid Production by Lactiplantibacillus plantarum strains Isolated from Ishizuchi-Kurocha

Background and Objective: Ishizuchi-kurocha is a post-fermented tea that involved two main kinds of microorganisms, namely fungi and lactic acid bacteria, which are primary and secondary fermentation, respectively. Therefore, this research aimed to confirm the role of Lactiplantibacillus plantarum during secondary fermentation of Ishizuchi-kurocha and the anti-bacterial effect due to lactic acid production and genes detection of plantaricin.Material and Methods: Antimicrobial were estimated using well diffusion method. Lactic acid was determined with spectrophotometric method. Detection of plantaricin genes were confirmed by Real-Time qPCR. The genes were sequenced through DNA Sequencing Analytical service by the Division of Genomic Research, Gifu University using the Multi -capillary DNA Sequencer ABI Prism 3100/3130 Genetic Analyzer and the data analyzed by the CLC Sequence Viewer 8.0 and BioEdit 7.2. Statistical analysis was evaluated by one-way of variance followed Tukey's post hoc test using RStudio version 4.1.3.Results and Conclusion: L. plantarum strain IYO1511 has higher antibacterial activities than strain IYO1501. In addition, L. plantarum strain IYO1511 produced higher lactic acid than strain IYO1501 and has plantaricin genes, plnA, plnEF, plnN, plnJ and plnK. However, L. plantarum strain IYO1501 only encoded plnEF, plnN, and plnJ. The plantaricin genes from the strains IYO1501 and IYO1511 were sequenced to identify the heterologous gene clusters of each species. It was discovered that plnA, plnEF, and plnJofL. plantarum IYO1511 showed 100% similarity homology toward GenBank. The plnN of strain IYO1511 and plnEF of IYO1501 present extra base pairs inserted into the DNA. L. plantarum strains can be used as food preservative for artificial fermentation to control the safety and quality of the product of Ishizuchi-kurocha.The lactic acid and plantaricin were expected to inhibit pathogenically and spoilage bacteria to produce a unique acidic flavor as well as fragrance to Ishizuchi- kurocha. Conflict of interest: The authors declare no conflict of interest.