Abstract
Benzo[a]pyrene (BaP) forms during high-temperature food processing and enters the body via ingestion, raising food safety concerns. Research on degrading food's toxic substances with food-derived microorganisms is crucial for food safety, the environment, and human health. In the present study, Bacillus haynesii TM-41 and Kluyveromyces marxianus TD-3 were isolated from BaP-degrading kefir, and a co-culture system was constructed by pure culture and co-culture degradation experiments. Under the conditions of an initial BaP concentration of 19 mg/L, a temperature of 35°C, a pH value of 6.0, a degradation time of 78 h, and a final degradation rate of BaP by the co-culture system reached 71.08%. Metabolomics results showed that the TD-3 in the co-culture system degraded and utilized BaP to provide energy for its partner, TM-41. Conversely, TM-41 synthesizes and secretes specific amino acids, which are assimilated by TD-3 to fulfill its nutritional demands for growth. This study elucidated the synergistic mechanism of co-cultured microorganisms for the degradation of BaP and highlights the potential of food microbial strain resources for the removal of BaP. IMPORTANCE: Benzo[a]pyrene (BaP) generated during thermal food processing is of serious threat to food safety. Microbial degradation has become the preferred option for the removal of BaP due to its high efficiency, low cost, and sustainability. In our study, the degradation efficiency of benzopyrene was enhanced by constructing a co-culture system of food microbial strains. Metabolomics disclosed the bacterial-fungal synergistic degradation mechanism in this system: yeast degraded and utilized BaP to provide energy for the bacteria, while the latter supplied amino acids for the yeast to fulfill its nutritional demands for growth.