松茸的发酵条件优化及其对酪氨酸酶的抑制机理研究OA北大核心CSTPCD

in this study,Tricholoma matsutake was fermented by using Lactobacillus acidophilus,to improve its tyrosinase inhibitory activity.The mechanism of activity change in Tricholoma matsutake after fermentation was also explored.The fermentation conditions were optimized by a single-factor experiment.The effects of fermentation on active ingredients were analyzed using the phenol-sulfuric acid meth-od,bicinchoninic acid method,and HPLC.Further,the interaction between fermented Tricholoma matsutake and tyrosinase was investiga-ted by using enzymatic reaction kinetics analysis,copper ion chelation assay,and tyrosinase fluorescence quenching assay.Results showed that the highest tyrosinase inhibition rate of fermented Tricholoma matsutake was observed at 5％inoculation amount of Lactobacillus aci-dophilus,4％of matsutake mushroom,and 4 days of fermentation time.And the IC50 value decreased from over 10 mg/mL to(4.74±0.21)mg/mL after fermentation.The content of total protein and oligopeptides(＜1 000 Da)was increased after fermentation,suggesting that the fermentation improved the release of bioactive oligopeptides and free amino acids.Further mechanistic studies indicated that the fermented Tricholoma matsutake reduced tyrosinase activity by mixed reversible inhibition.In this process,it chelated copper ions at a semi-chelating concentration of(9.14±0.04)mg/mL and then quenched the endogenous fluorescence of tyrosinase.This indicated that the fermented Tricholoma matsutake may occupy the active site of tyrosinase by binding to copper ions,thereby inhibiting its activity.Re-sults showed that the tyrosinase inhibition ability of Tricholoma matsutake could be significantly improved after fermentation by Lactobacil-lus acidophilus.This work could lay a scientific foundation for its utilization in cosmetics and functional foods.