Screening of Plant-Derived Lactic Acid Bacteria for Faba Bean Fermentation and Their Mycotoxin Removal Capacity

The development of novel plant-based products using unconventional food matrices increases the risk of introducing mycotoxins into the food system. Biological detoxification methods, particularly those involving lactic acid bacteria (LAB), are considered sustainable and safe strategies. In this study, we screened 142 plant-derived LAB strains across 17 species for their fermentation performance and mycotoxin removal capacity during faba fermentation. Among them, 84 strains showed rapid acidification. The plating of 11 selected strains confirmed robust growth with cell densities ranging from 4 × 108 to 2.18 × 109 CFU/mL. Screening for aflatoxin B1 (AFB1) removal in complex medium identified several strains that could reduce AFB1 in the supernatant. However, complete toxin extraction after faba fermentation indicated that AFB1 was not enzymatically degraded. Similarly, no significant degradation of ochratoxin A or zearalenone was observed during faba fermentation. Additionally, a cell binding test with 11 selected strains showed that all strains bound AFB1, with efficiencies from about 10% to 35%. Notably, Lentilactobacillus hilgardii NFICC857 demonstrated the highest binding capacity, which has never been reported before. Our study provides preliminary insight into plant-derived LAB in mycotoxin removal. Given the vast unexplored diversity of LAB in nature, the discovery of novel strains with enhanced mycotoxin-binding capacity and potential enzymatic degradation remains promising.