摘要
纯化表征了枯草芽胞杆菌Bacillus subtilis CN7产生的2种不同形态的不依赖Ca2+的α-淀粉酶,对其酶解产物进行了高效液相色谱(HPLC)分析。结果表明:通过加热除杂、超滤、(NH4)2SO4沉淀和分子筛层析,一次性获得了纯化倍数提高36倍的电泳纯成熟肽形式α-淀粉酶Amy7B和提高75倍的截短体形式α-淀粉酶Amy7S;Amy7B和Amy7S的最适pH为6.5,最适温度为65℃,酶活性均不依赖于乙二胺四乙酸(EDTA)和Ca2+;酶解产物主要由葡萄糖和麦芽糖组成。Amy7B的相对分子质量为6.7×104,半衰期温度为59.6℃,比活力为(905.99±96.52)U/mg。与之相比,Amy7S的相对分子质量小约2.0×104(为4.7×104),半衰期温度高2.7℃(为62.3℃),比活力高1.05倍(达到(1 853.87±75.61)U/mg)。
Two forms of Ca2＋independent α-amylases （AmyTB and Amy7S） , from Bacillus subtilis CN7, were purified and characterized. The enzymatic starch hydrolysis products were analyzed by HPLC. The results showed that the Amy7B was purified by 36 fold and Amy7S was purified by 75 fold simultaneously after thermal denaturation, ultrafihration, ammonium sulfate precipitation, and molecular sieve chroma- tography. Both forms had the the same optimum pH 6.5, the same optimum temperature of 65 ℃ and very similar amylolytic pattern. Calcium ions and EDTA had no significant effects on their activities. However, the Amy7S （4.7×104） was approximately 2.0 × 104, shorter than the Amy7B （6. 7×104 ）, the half inactivation temperature and the specific activity of Amy7S were 62.3 ℃ and （ 1 853.87 ± 75.61 ） U/rag, they were higher than that at 59.6 ℃ and （905.99±96.52） U/rag of Amy7B.
出处
《生物加工过程》
CAS
CSCD
2012年第5期44-49,共6页
Chinese Journal of Bioprocess Engineering
基金
广西自然科学基金重点资助项目(2010GXNSFD013030)
广西培养新世纪学术和技术带头人专项资金资助项目(2009115)
广西科学院院基金(09YJ17SW02)
关键词
耐酸
淀粉酶
枯草芽胞杆菌
钙
水解产物
aciduric
α-amylase
Bacillus subtilis
calcium
starch hydrolysis
