漆酶交联聚集体的制备及其在玉米赤霉烯酮降解中的应用OA

Laccase is playing an increasingly important role in mycotoxin degradation;however,its practical application is largely hin-dered by high cost and poor stability.To address these limitations,this study successfully immobilized laccase using cross-linked enzyme aggregates(CLEAs)technology,resulting in the preparation of laccase cross-linked aggregates(PpLac-CLEAs).Results showed that the optimal preparation conditions were 0.52 g/mL of ammonium sulfate as precipitant,0.5％(v/v)of glutaraldehyde as cross-linker,and a cross-linking time of 4 h.Under these conditions,the activity recovery of PpLac-CLEAs reached 58.43％.After immobilization,the opti-mal pH and temperature for PpLac-CLEAs were identified as 3.0 and 45 ℃,respectively.Moreover,within the pH range of 4.0 to 11.0,the relative enzyme activity remained above 90％,demonstrating a broader operational range for both temperature and pH.Compared with the free enzyme,PpLac-CLEAs exhibited 26.42％,44.68％,and 43.92％higher tolerance toward Fe2+,Ag+,and Tween 80,respec-tively.In addition,PpLac-CLEAs retained 63.4％of their initial activity after six repeated uses.After 21 days of storage at 4 ℃,the re-sidual activity of PpLac-CLEAs was 64.49％,approximately three times that of the free enzyme.Fourier transform infrared spectroscopy analysis revealed significant changes in the enzyme secondary structure after immobilization,α-helix content increased by 3.6％,while β-turn content decreased by 6.95％,indicating enhanced structural rigidity that contributed to improved stability.In application tests,PpLac-CLEAs achieved a 29.47％degradation rate of zearalenone in corn slurry.In conclusion,PpLac-CLEAs exhibit significantly en-hanced stability and reduced application costs,showing promising potential for mycotoxin degradation.