Immobilization of laccase in poly(acrylamide-crotonic acid)/sodium alginate, poly(acrylamide-crotonic acid)/k-carrageenan poly(acrylamide-citraconic acid)/sodium alginate, poly(acrylamide-citraconic acid)/k-carrageenan

In this study, laccase enzyme was immobilized using entrapment method in poly(acrylamide-crotonic acid)/sodium alginate, P(AAm-CrA)/Alj, poly(acrylamide-crotonic acid)/K-carrageenan, P(AAm-CrA)/K-kar, poly(acrylamide-citraconic acid)/sodium alginate, P(AAm-CA)/Alj, poly(acrylamide-citraconic acid)/K-Carrageenan, P(AAm-CA)/K-kar semi-interpenetrating network (semi-IPNs). Optimum pH was determined between 5,0-6,0 for free laccase and immobilized laccases. Optimum temperature was determined between 40 0C - 50 0C for free laccase and immobilized laccases. After 42 days of storage at 4 oC, free laccase and P(AAm-CrA)/Alj, P(AAm-CrA)/K-kar, P(AAm-CA)/Alj, P(AAm-CA)/K-kar immobilized enzymes retained %55 and % 71, % 70, % 73, % 68 of their original activities, respectively. P(AAm-CrA)/Alj, P(AAm-CrA)/K-kar, P(AAm-CA)/Alj, P(AAm-CA)/K-kar immobilized enzymes used repeatedly 10 times in a day and they were retained %62, % 56 % 53, %50 of their original activities, respectively. Km and Vmax were calculated for free laccase as Km value is 6,70x10-3 mM, Vmax value is 1,80x10-3 mM.min-1 and for P(AAm-CrA)/Alj, P(AAm-CrA)/K-kar, P(AAm-CA)/Alj, P(AAm-CA)/K-kar immobilized laccases Km values are 7,90x10-3 mM, 8,40x10-3 mM, 7,00x10-3 mM and 1,02x10-2 mM and Vmax values are 3,70x10-3 mM.min-1, 3,50x10-3 mM.min-1, 8,01x10-4 mM.min-1 and 1,01x10-2 mM.min-1, respectively. Inactivation rate constants (ki) of immobilized laccases at 30 °C and 50 °C were found between 0,0013 min-1-0,0085 min-1 and 0,0036 min-1-0,0201 min-1. Percent decolorization of methyl orange by free enyzme and enyzmes immobilized in P(AAm-CrA)/Alj, P(AAm-CrA)/K-kar, were found as %63 and %38, %45. Percent decolorization of methyl orange in the presence of mediator by free enyzme was found %73 and enyzmes immobilized in P(AAm-CrA)/Alj, P(AAm-CrA)/K-kar, were found as %72.