真菌α-淀粉酶制剂的提纯及保存方法

以米曲霉ZLF13菌株经固态发酵生产的真菌α-淀粉酶粗制品(发酵曲)为原料,对其提纯、精制的工艺条件和保存方法进行了研究。其最佳提纯工艺条件为:培养好的发酵曲采用40℃温水,pH值7.5左右,加水比为1∶4,浸泡3 h。压滤滤液经超滤浓缩后,在10~15℃,pH 6.0~6.5,与食用酒精混合为酒精体积分数为70%的溶液中静置沉析,过滤后于40℃低温干燥。采用该工艺条件进行粗酶提纯,产品综合回收率稳定在70%以上,最高达到74%,产品酶活力最高达25 416 u/g,平均达16 608 u/g,卫生标准达到食品级标准。通过精制酶的保存试验研究,确定了一种真菌α-淀粉酶稳定剂配方,其添加至精制酶后,常温下半年的酶活力保存率达到95%以上,1年的保存率可达到90%以上。

Study on Purification Technology and Method for Keeping Fungus α- Amylase

The crude Fungus α-Amylase preparation was obrained by solid-state fermentation of Aspergillus oryzae(ZLF13).The Purification or refinement and storage method was studied.The optimal refinement technology was that the fermentation productions were dipped in 4 times volume of water as the fermentation productions at 40℃ and pH 7.5.for 3 hours.Filtration was operated and the ultrafiltration ensued.The concentrated liquid was mixed with alcohol and the final concentration of alcohol reached to 70%.The refined solid was dried at 40℃.Under such conditions,the product yield was higher than 70%,the maximum to 74%.The highest activity of enzyme was (25 416) u/g and the average level was(16 608) u/g.The experiment showed that stabilizer blend,which proportion was determined by tests,can keep the activity higher than 95% for half-year and 90% for one year at room temperature.