摘要
从富含淀粉质的土壤中筛选到1株耐酸性α-淀粉酶的产生菌株ZY8,经初步鉴定为黑曲霉。并对其液态发酵条件进行了研究,产酶适宜培养基为可溶性淀粉50g/L,柠檬酸氢二铵20g/L,KH2PO43g/L,CaCl20.1g/LF,eSO4.7H2O0.01g/L,MgSO4.7H2O1g/L。以2%的接种量在30℃、120r/min、初始pH4.0的条件下培养72h,酶活力达到19.86U/mL。酶学特性研究表明,该耐酸性-α淀粉酶最适反应温度为70℃,最适反应pH值为2.0～5.0,在90℃高温处理20min酶活力仍然保持在80%以上。
An aciduric a-amylase-producing strain named ZY8 was isolated from starch-rich soil and was primarily identified as Aspergillus niger. The liquid-state fermentation conditions of ZY8 were studied. The optimal medium for enzyme production contains 50 g/L soluble starch, 20g/L ammonium citrate dibasic, 3g/L KH2PO4, 0.1g/L CaCl2, 0.01 g/L FeSO4-7H2O and 1 g/L MgSO4·7H2O. The activity of aciduric a-amylase reached 19.86 U/mL when strain ZY8 was cultured at 30℃ and 120 r/min for 72 h with inoculum of 2% and initial pH of 4.0. From zymological analysis, it was indicated that the optimal temperature and pH for the aciduric a-amylase was 70℃ and 2.0-5.0, respectively. Over 80% of the enzyme activity was hold after the treatment at 90℃ for 20 min.
出处
《中国酿造》
CAS
北大核心
2007年第4期30-34,共5页
China Brewing
基金
安徽省高"校十五"优秀人才计划(【教秘人】2004-100)
关键词
黑曲霉
耐酸性Α-淀粉酶
筛选
发酵条件
酶学性质
Aspergillus niger, aciduric or-amylase
screening
fermentation condition
zymological property
