湘莲中产耐酸性α-淀粉酶菌株的分离及鉴定  

Isolation and characterization of an acid-stable α-amylaseproducing strain from Xiang lian

作　　者：凌玲[1] 金元昌[1] 张建贺 蔡英桂 苏壬香 吴银亮[1] 

机构地区：[1]湖南科技大学生命科学学院,湖南湘潭411201

出　　处：《中国生物制品学杂志》2014年第8期1006-1009,共4页Chinese Journal of Biologicals

基　　金：国家级大学生创新创业训练计划项目(201210534010)

摘　　要：目的从湘莲中分离产耐酸性α-淀粉酶菌株,并对其进行鉴定。方法采用淀粉富集培养基分离湘莲中产α-淀粉酶菌株,通过形态学、生理生化分析及16S rDNA序列分析进行鉴定;在不同pH(3.20、3.38、3.56、3.85、4.15和4.45)条件下培养筛选出的菌株,测定酶活力,确定产酶的最适pH;在不同温度(25、30、35和40℃)条件下培养耐酸性α-淀粉酶产生菌,测定酶活力,确定产酶的最适温度;用不同碳源(蔗糖、淀粉和葡萄糖)和不同氮源[牛肉膏、(NH4)2SO4、柠檬酸氢二铵、柠檬酸三铵和蛋白胨]培养耐酸性α-淀粉酶产生菌,测定酶活力,确定产酶的最适碳源和氮源。结果从湘莲样品中筛选出2株酶活力较高的菌株,酶活力分别为376.21和395.62 U/ml,分别编号为LL5和LL9,2株菌株均为解淀粉芽胞杆菌。菌株LL5产α-淀粉酶的最适pH为3.56,最适温度为34℃,最适碳源为葡萄糖,最适氮源为柠檬酸三铵,为耐酸性α-淀粉酶产生菌。结论成功从湘莲中分离出1株产耐酸性α-淀粉酶菌株LL5。Objective To isolate and identify an acid-stable α-amylase-producing strain from Xiang lian. Methods An acid-stable α-amylase-producing strain was isolated from Xiang lian by using starch enriched medium, and identified by morphological, physiological and biochemical tests as well as 16S rDNA sequencing. The screened strain was cultured at various pH values （3. 20, 3. 38, 3.56, 3.85, 4. 15 and 4. 45）, temperatures （25, 30, 35 and 40 ℃） using various carbon sources （sucrose, starch and glucose） and nitrogen sources （beef extract, ammonium sulphate, diammonium citrate, ammonium citrate and peptone） and determined for enzyme activity to optimize culture condition. Results Two α- amylase-producing strains, LL5 and LL9, were screened, with enzyme activities of 376. 21 and 395.62 U/ml respectively, both of which were Bacillus amyloliquefaciens. LL5 was identified as an acid-stable α-amylase-producing strain, of which the optimal pH value, temperature, carbon source and nitrogen source were 3.56, 34 ℃, glucose and ammonium citrate respectively. Conclusion An acid-stable a-amylase-producing strain was successfully isolated from Xiang lian.

关 键 词：湘莲 淀粉酶 分离 

分 类 号：Q815[生物学—生物工程]