Laccase production by newly isolated white rot fungus Funalia trogii: Effect of immobilization matrix on laccase production

摘要

The laccase production performance of newly isolated Funalia trogii (F. trogii) immobilized on low-cost activated adsorbents prepared from apricot stone was investigated in inexpensive molasses medium and compared with free pellets. The adsorbents were apricot stone-based activated carbon (AC), Cu-impregnated apricot stone-based activated carbon (Cu-AC) and Fe-impregnated apricot stone-based activated carbon (Fe-AC). Cu-AC and Fe-AC were prepared by chemical activation. The values of BET surface area (S_(bet)). total pore volume (V_t), micropore surface area (S_(mic)) and micropore volume (V_(mic)) which show the pore properties of the activated carbons were 133 m~2 g~(-1),0.105 cm~3 g~(-1), 108 m~2 g~(-1) and 0.056 cm~3 g~(-1) for Cu-AC and 145 m~2 g~(-1), 0.112 cm~3 g~(-1), 117 m~2 g~(-1) and 0.061 cm~3 g~(-1) for Fe-AC, respectively. F. trogii attached well on all of these adsorbents. However, the fungus immobilized on Cu-AC produced much higher levels of laccase than the others. The laccase activity obtained in 5 g L~(-1) molasses media after first cycle and mean laccase activity obtained after three cycles with fungus immobilized on Cu-AC were 29.23 U mL~(-1) and 27.04 U mL~(-1), respectively. These activities were only 0.25 and 0.39 U mL~(-1) with free pellets. The crude laccase from immobilized culture could also decolorize the textile dyes.