摘要
高温放线菌V_4菌株(Thermoactinomyces sp.V_4)产生的β-淀粉酶最适反应温度为70℃,最适pH为6,酶的热稳定性良好,50℃(4h)不失去酶活力,55℃(2h)保持最初活力的92%,酶对可溶性淀粉的水解率达77%,纸层析结果显示水解产物主要为麦芽糖,经旋光测定,水解产物具有β-构型。巯基抑制剂对此β-淀粉酶无抑制作用。V_4菌株同时产生异淀粉酸及少量的α-淀粉酶。
Crude β-amylase produced by Thermoactinomyces sp. V_4 has an opti-mun temperature at 70℃ and was quite stable at 50℃, 92% of originalactivity remained after treatment at 55℃ for 2h. The enzyme was mostactive at pH6--8. The conversion rate of soluble starch to maltose wasabout 77% under the catalysis of crude enzyme. The mutarotation of theproducts from dextrin by the enzyme confirmed that the formed maltosewas in β-form. Sulfhydryl reagents had no effect on the β-amylase.
出处
《生物工程学报》
CAS
CSCD
北大核心
1991年第2期148-153,共6页
Chinese Journal of Biotechnology
关键词
Β-淀粉酶
耐热性
高温放线菌
β-amylase
heat-stability
maltose
Thermoactinomyces
