Obtaining peroxidase from Zanthoxylum armatum DC. fruit and application in detoxification of phenol wastewater

The important role of peroxidase in plant physiology and biocatalysis has attracted much attention. To evaluate the specific properties of the peroxidase from Zanthoxylum armatum DC. fruit and its performance in phenol removal and detoxification. This study obtained low-purity peroxidase from Z. armatum fruit for the first time via three-phase partitioning with a yield of 160 mg/100 g, purification fold of 12.8, and recovery rate of 83 %. Afterward, SuperTandex-75 gel was used for further purification. The result of liquid chromatography-tandem mass spectrometry, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and native-polyacrylamide gel electrophoresis revealed that the enzyme contained isoenzymes with different molecular weights (46.32, 39.41, 35.03, and 9.06 kDa). Enzymatic characterization study found that compared with commercial peroxidase, the enzyme showed better pH, temperature, and metal ion stability, however, 10 mM concentrations of ascorbic acid and citric acid could inhibit its activity by more than 90 %. Regarding the phenol bioconversion, when the enzyme activity of the system is 200 U/mL, the phenol concentration of 5-10 mM can be reduced by more than 80 % under optimal conditions. The detoxification effect of low-purity peroxidase on phenol water was tested using Vigna radiata (Linn.) Wilczek. The reduced toxicity of phenol water after treatment promoted the growth of plants, indicating that the phenol water after degradation by the low-purity peroxidase can be used in agricultural production, and it also proved that the enzyme is a promising peroxidase. In addition, the present study provides data for the selection of inhibitory peroxidase activity parameters in the food processing of Z. armatum fruit.