Investigation of the optimum conditions of immobilized and free laccase enzyme and its use in decolorization process

In this study, Laccase enzyme (L) from Tramatesversicolor was entrapped into poly(N-isopropylacryl amide)-calcium alginate (P(NIPA)-CaAlj) beads The properties of the immobilized enzyme and use of enzymatic decolorization processes were investigated and compared with those of the free enzyme. Michaelis-Menten constant (Km) and maximum reaction rate (Vmax) values were found to be 1.70x10-2 mM and 2.08x10-3 mM.min-1 for free enzyme respectively. Km and Vmax values were found as 4.80x10-2 mM and 8.70 x 10-3 mM.min-1 for entrapped enzymes respectively. Optimum pH was determined as 5.0 and 6.0 and optimum temperature determined as 40oC and 45oC for free laccase and entrapped laccase respectively. After 30 days of storage at 4 oC free laccase retained 60 % of its original activity. Also after 30 days of storage at 4 oC, entrapped enzymes were retained 83 % its original activity. Immobilized enzyme was used repeatedly 10 times, were retained 77 % of its original activities. Percent decolorization of methyl orange by free enyzme and entrapped enyzmes were found to be 73% and 70%, respectively