RESUMEN
Recovery difficulty and inactivation of laccases are major challenges that hamper their application in biotechnology. In this study, laccase was purified from Cyberlindnera fabianii using ion-exchange and gel filtration chromatography with homogeneity confirmed by sodium dodecyl sulphate polyacrylamide gel electrophoresis. Purified laccase of 52â¯kDa was immobilized on calcium and copper alginate beads by entrapment method. Free and immobilized enzymes were characterized, and efficiency of bisphenol A (BPA) degradation was determined. pH optima for free and immobilized laccases were 5.0 and 6.0, respectively. Ca and Cu alginate immobilized laccase (Ca-AIL and Cu-AIL) had optimum activity at 60⯰C and 50⯰C, respectively while free laccase (FL) was at 40⯰C. Km and Vmax of FL, Ca-AIL and Cu-AIL were 0.032â¯mM and 15â¯mM/min, 0.078â¯mM and 6.98â¯mM/min, and 0.091â¯mM and 5.61â¯mM/min, respectively. Remarkably, immobilized laccases had higher operational stability than FL over 21â¯d at 4°C. Reusability of immobilized laccase was effective for 3â¯cycles with residual activity above 70%. Notably, Ca-AIL and Cu-AIL exhibited 71% and 65.5% BPA degradation efficiency on 14â¯d. Results reveal good kinetic parameters, improved thermal stability and enhanced reusability of immobilized laccase from C. fabianii with potentials for various industrial applications and bioremediation.