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以重组植酸酶(phyA-ABCD5F7)的毕赤酵母工程菌为植酸酶生产菌,经高密度发酵制备得到粗酶液。通过在粗酶液中添加Mg~(2+)和Zn~(2+)等金属离子以及海藻糖,可明显提高植酸酶的热耐受能力。以植酸酶的酶活回收率为评价指标,考察了进风温度、出风温度和保护剂对植酸酶酶活回收率的影响,确定最佳喷雾条件:保护剂5 g/L MgSO_4·7H_2O、2 g/L ZnSO_4·7H_2O和10 g/L海藻糖,进风温度为160℃,出风温度为70~75℃,在此条件下,植酸酶的酶活回收率达80%。
The recombinant phytase (phyA-ABCD5F7) Pichia engineered bacteria as phytase producing bacteria, prepared by high-density fermentation crude enzyme solution. By adding metal ions such as Mg2 + and Zn2 + and trehalose in the crude enzyme solution, the heat tolerance of phytase can be obviously enhanced. Taking phytase activity recovery as evaluation index, the effects of inlet temperature, outlet air temperature and protective agent on phytase activity recovery were investigated. The best spray conditions were determined: protective agent 5 g / L MgSO 4 · 7H_2O, 2 g / L ZnSO_4 · 7H_2O and 10 g / L trehalose. The inlet air temperature was 160 ℃ and the outlet air temperature was 70 ~ 75 ℃. Under these conditions, the phytase activity recovery was 80%.