Immobilization and characterization of laccase from Chinese Rhus vernicifera on modified chitosan

Rhus laccase (RL) was immobilized on water-soluble chitosan (WSCT) and chitosan microsphere (CTMS) by various methods,and their properties were compared with transitional metal (Fe3+)-immobilized laccase in chelation.The immobilization yield (IY) on WSCT was not significantly affected by the methods used;the recovery activity of the enzyme had relation:FeCl3-RL>RL-WSCT>RL-CTMS.The effects exist between the special dimension of the supports and the IY.After immobilization,the suitable pH and temperature of the enzyme were significantly improved.After three months at 4℃,the losses of activity were 10% (FeCl3-RL) 10%(RL-WSCT) and 15%(RL-CTMS),respectively;the activity remained 80% for RL-WSCT and 85% for FeCl3-RL after use 15 times.