Abstract:Lactobacillus plantarum QH06, a bacterium capable of scavenging ochratoxin A (OTA), was isolated through a screening process. Its OTA scavenging mechanism and efficacy in removing OTA from food items were subsequently evaluated. The OTA scavenging potential of L. plantarum QH06 active cells, inactive cells, intracellular and extracellular metabolites, and cell walls were investigated to elucidate the methods by which L. plantarum QH06 scavenges OTA. The practical application of L. plantarum QH06 was evaluated by analyzing its capacity to scavenge OTA in grape juice. The OTA scavenging rates of active and inactive L. plantarum QH06 cells were 83.61% and 83.51%, respectively, after co-culturing with 100 ng/mL of OTA for 48 h. The OTA concentration was still >90 ng/mL after co-culturing QH06 intracellular enzymes or extracellular metabolites with 100 ng/mL OTA for 72 h. However, the OTA concentration decreased from 80.75 ng/mL (0 h) to 13.81 ng/mL after co-incubating QH06 cell walls with 100 ng/mL OTA for 72 h, for a scavenging rate of 82.90%. Furthermore, the concentration of OTA in grape juice decreased from 100 ng/mL to 15.23 ng/mL after QH06 was co-cultured with grape juice containing 100 ng/mL of OTA for 72 h. In grape juice containing 20 ng/mL OTA, QH06 exhibited a 100% OTA scavenging rate. The results indicate that L. plantarum QH06 effectively scavenges OTA present in food through cell wall adsorption, providing a theoretical basis for its potential application in the mitigation and management OTA contamination in food.
