A novel strain Lactiplantibacillus plantarum LPP95 isolated from Chinese pickles: Antifungal effect, mechanism, and potential application in yogurt

This study investigated the antifungal effect, mechanism, and potential application in yogurt of Lactiplantibacillus plantarum (L. plantarum) LPP95 isolated from Chinese pickles. The L. plantarum LPP95 showed a high inhibitory effect on the growth of five molds, with the strongest inhibitory effect observed on Penicillium sp. The cell-free supernatants (CFS) of L. plantarum LPP95 resulted in the shrinking of Penicillium sp. spores, and destroyed the integrity of the cell wall and membrane of spores, causing the leakage of nucleic acid from cells. The antifungal activity of CFS was not decreased after heat or proteolytic enzyme treatment but was affected by pH change. The inhibitory activity of CFS was associated with organic acids, and 66 organic acids were identified by LC-MS analysis. In addition, the validation experiments showed that trans-cinnamic acid, citric acid, trans-3-indolea- crylic acid, and DL-4-hydroxyphenyllactic acid all exhibited antifungal activity. Moreover, L. plantarum LPP95 effectively inhibited the growth of Penicillium sp. in yogurt. Overall, L. plantarum LPP95 and its CFS have the potential as biological preservatives.