Isolation and identification of lactic acid bacteria with efficient patulin degradation ability and its degrading characteristics

Objective:To screen and identify a lactic acid bacteria(LAB) strain with patulin(PAT) detoxification ability from fermented food. Methods:LAB strains isolated from fermented vegetables were co-cultured with PAT. Then the HPLC method was executed to determine the PAT residue after co-culture and one LAB strain with high PAT-degrading ability was selected for further study. The PAT removal efficiency of viable cells and dead cells,as well as different cell components including cell pellets,cell walls and cell extracts were compared,and the factors that impact the capability of PAT degradation of this strain were studied. Moreover,the strain's taxonomy was confirmed based on morphology characteristics and 16 S r DNA gene sequence analysis. Results:A LAB strain with high PAT-removing ability was screened out and identified as a Lactobacillus plantarum. The PAT removal efficiency of dead cells and cell wall were much lower than cell pellets,indicating that the removal mechanism may be attributed to biodegradation. This L. plantarum strain had high PAT-removing ability at temperature of 20~30 ℃ and p H of 3~7. Conclusion:The L. plantarum strain LB-11 had a high removal ability of PAT. The removal efficiency of PAT could reach 98.34% under appropriate conditions within 24 h. This strain could be regarded as a probiotic with potential application on PAT removal.