工业微生物Issue(2)：47-54,8.DOI:10.3969/j.issn.1001-6678.2015.02.008
中温α-淀粉酶在地衣芽孢杆菌中的异源表达
Heterologous expression of medium temperature α-amylase in Bacillus licheniformis
摘要
Abstract
To increase the fermentation temperature of α-amylase is of great significance for decreasing cooling water consumption and cost of production. In this study,the gene amyL encoding the thermostableα-amylase of B. licheniformis CBBD302 was deleted by homologous recombination. The resulting mutant strain B. licheniformis D402 was then used as a host cell to overexpress BaA. Afterwards,the recombinant plasmid pHY-WZX-BaA harboring the gene encoding B. amyloliquefaciens α-amylase (BaA)was constructed and transformed to D402 strain. The recombinant D402/pHY-WZX-BaA strain was obtained and also used for fermentation experiments. Under shake-flask conditions,the optimal fermen-tation temperature of the recombinant D402/pHY-WZX-BaA strain was 42 ℃. By comparison,the original strain B. amyloliquefaciens M23 exhibited optimal performance at 34 ℃. Furthermore,301 U/mL was the highest amount of produced enzyme obtained under the shake-flask condition and 531 U/mL was the highest amount of produced enzyme obtained after 78 h of fermentation in a 30 L fermentor. The recombinant enzyme showed an optimal performance at 60 ℃and pH 6. 5. This enzyme could also be inactivated completely by incubating at 90 ℃ for 20 min. Similar to the original products,the recombinant enzyme could remain stable at starch gelatinization temperature and be inactivated conveniently.关键词
中温α-淀粉酶/解淀粉芽孢杆菌/地衣芽孢杆菌/异源表达Key words
medium-temperature α-amylase/Bacillus amyliquefaciens/Bacillus licheniformis/heterologous expression引用本文复制引用
范如意,牛丹丹,应喜娟,沈微,陈献忠..中温α-淀粉酶在地衣芽孢杆菌中的异源表达[J].工业微生物,2015,(2):47-54,8.基金项目
国家863高技术研究发展计划（2013AA102101-5）；江苏省科技支撑计划（No． BE2012618）。 （）
