**2.1 Microorganism**

Stock cultures of *L. plantarum* strains were preserved in a freezer at −80°C, in cryotubes containing 10% glycerol. The culture was stored at the Indonesian Institute of Sciences, which is located in Bogor, Indonesia. The strain was inoculated into MRS broth medium (Merck, Germany) for regeneration and incubated at 37°C.
