<正>Aspergillus oryzae 3042 mycelium pellets were immobilized by crosslinking method with reagents of gelatin and formaldehyde. An orthogonal design table was used to determine the optimal immobilization conditions. The L-aminoacylase activity of immobilized mycelium pellets under optimal conditions was assayed. The results show that the L-aminoacylase activity was 1 350 U·g-1. and the activity retention rate was 83%. The properties of the immobilized preparation were studied. Compared with free pellets, the appropriate pH of reaction system changed from 7.0 to 8.0, temperature changed from 52℃to 63℃, and the ranges of the optimum reaction conditions were all improved. The effect of Co2+ on immobilized mycelium pellets was investigated and the favorable concentration was determined. When the immobilized preparation was used for the resolution of D, L-alanine in a packed bed reactor with 10 mm in diameter, 200 mm in height, the operational stability was increased, and the half-life period was 53 d. Thermal stability analysis shows that the immobilized pellets were more stable than the free pellets.
