Alternaria gaisen is one of the main fungi that cause fruit postharvest diseases due to its wide contamination and toxin production. The application of lactic acid bacteria shows great industrial application as a natural food preserver due to the advantages of being safe and non-toxic. In order to obtain a natural preservative against this fungus, this study aimed to evaluate the effectiveness of cell- free supernatants (CFS) produced by Lactobacillus pentosus 86 as antimicrobials in vitro against A. gaisen. Results indicated that CFS displayed excellent thermostability and enzymatic stabilities with an antifungal activity over 85%. Under thermal (40–100 °C) treatments, different protease solution and acidic conditions (pH 2–4), the antifungal activity of CFS maintained up 80%. However, when the pH reached 6, its antifungal ability completely disappeared. CFS inhibited mycelial growth of A. gaisen by destroying the hyphae membrane, leading to the leakage of nucleic acids and proteins, and hyphae collapsed and shriveled. CFS also changed the spore’s morphology, resulting in cell membrane damage, intracellular leakage, and organelles aggregation. The increase of cell membrane permeability of spores caused a 30% mortality rate. Therefore, the CFS of L. pentosus 86 has the potential for controlling fruit diseases caused by A. gaisen.

This study investigated the fermentation of isolated soy glycinin by using the Lactiplantibacillus plantarum B1-6 strain, its reduction effect on immunoglobulin E (IgE) reactivity, the relationship with protein aggregation/gelation state and conformational changes. Fermentation was performed under different glycinin concentrations (0.1%, 0.5%, 1% and 2%, w/v) and varied fermentation terminal pH levels (FT-pH) (pH 6.0, 4.5, 4.0 and 3.5). L. plantarum B1-6 showed potency in reducing immunoreactivity to 0.10–69.85%, as determined by a sandwich enzyme-linked immunosorbent assay. At a FT-pH of 6.0 and 4.5, extremely low IgE reactivity (0.1–22.32%) was observed. Fermentation resulted in a great increase (2.31–6.8-fold) in particle size and a loss of intensity in A3 and basic subunits. The conformation of glycinin was altered, as demonstrated by improved surface hydrophobicity (1.33–7.39-fold), decreased intrinsic fluorescence intensity and the α-helix structure. Among the four selected concentrations, glycinin at 1% (w/v, G-1) evolved the greatest particles during fermentation and demonstrated the lowest immunoreactivity. Principal component analysis confirmed that particle size, intrinsic fluorescence intensity, α-helix and ionic bond were closely related to immunoreactivity reduction.