解淀粉芽孢杆菌（Bacillus amyloliquefaciens）是一类重要的工业微生物，在农业、医药和食品等领域有广泛用途。为了开发高效的基因操作技术，在解淀粉芽孢杆菌中引入单链核苷酸（ssDNA）介导的同源重组方法。首先，通过敲除mutS基因干扰解淀粉芽孢杆菌的错配修复系统，然后导入单链结合蛋白（Beta）表达质粒，构建了宿主菌B. amyloliquefaciens XH7(mutS-，bet+)。其次，通过设计88 bp的ssDNA电转化导入以上构建的宿主菌中实现了以rpoB基因为靶点的有效同源重组，转化株产生利福平抗性。实验优化了ssDNA介导同源重组的参数：75 μg的ssDNA，电转细胞复苏时间为6~12 h。本研究首次成功实现了ssDNA同源重组技术在解淀粉芽孢杆菌的应用，对解淀粉芽孢杆菌和其它难转化的芽孢杆菌属进行有效的遗传操作手段提供新的思路。

Bacillus amyloliquefaciens is an important industrial microorganism that has been widely used in agriculture, pharmaceutical, and food industries. In order to develop highly efficient genetic manipulation techniques in B. amyloliquefaciens, a single-stranded oligonucleotide (ssDNA)-mediated recombination method was introduced. First, the mutS gene involved in mismatch repair was knocked out, followed by introduction of the expression plasmid for the bet gene encoding the beta protein (a ssDNA-binding protein) into B. amyloliquefaciens, to construct the B. amyloliquefaciens XH7 host (mutS-，bet+), where the mutS gene was inactivated and the beta protein was expressed. Second, homologous recombination targeting the ropB gene was successfully achieved by designing an 88-bp ssDNA oligonucleotide and transforming it into the B. amyloliquefaciens XH7 host (mutS-，bet+) by electroporation, followed by antibiotic selection. The parameters for ssDNA-mediated recombination were optimized as follows: 75 μg ssDNA oligonucleotide and 6 h to 12 h of cell recovery from electroporation. Here, oligonucleotide-mediated recombination was successfully applied in B. amyloliquefaciens for the first time, providing a new approach for developing an effective genetic manipulation technique in B. amyloliquefaciens and other Bacillus spp. that are not naturally transformable.

863计划资助项目（2014AA021304）；广东省自然科学基金资助项目（S2012030006235）；广东省科技计划资助项目（2013B010404007）；广州市科技计划项目（201510010191）；广东省科技计划项目（2013B090800003）；中央高校基本科研业务费专项资金项目（2015ZP032，2015ZZ040）