Cross-linked enzyme aggregates of β-glucosidase from Prunus domestica seeds.

Cross-linked enzyme aggregates (CLEAs) of β-glucosidase were prepared and characterized. Under the optimum conditions, the activity recovery of CLEAs reached 84 %. The reduction by NaBH(4) resulted in slightly lower activities of CLEAs, while their thermostability was enhanced. CLEAs were more thermally stable than free enzyme (half lives, 973 vs. 518 min at 50 °C), while less stable than seed meal (half life, 1,090 min). In 90 % (v/v) t-butanol, the half lives of CLEAs and free enzyme were 53 and 6.7 h, respectively. Besides, the catalytic efficiency (V (max)/K (m)) of CLEAs was comparable to free enzyme (0.42 vs. 0.47 min(-1) mg(-1)). This carrier-free immobilized enzyme had a network structure with multiple layers. The productivity of salidroside using CLEAs reached 150 g/l g catalyst, while being 6.3 g/l g with seed meal.