工业微生物菌种改良与重组工程技术

工业微生物菌种改良技术经历了诱变、遗传重组和基因工程技术改良菌种等三个发展阶段,第二代基因工程技术--基因打靶技术具有定位性强、打靶后新基因随染色体DNA稳定遗传的特点,使人们可以有目的地去改造生物的遗传物质,创造有利于生产的微生物新品种。重组工程技术是在大肠杆菌体内利用一个独立噬菌体重组系统,使用40～60bp的同源序列,高效催化线性打靶DNA片段与染色体DNA或质粒载体上的靶基因发生同源重组,对靶基因进行精确修饰。利用重组工程技术构建的打靶载体的同源序列长度可达10kb以上,甚至100kb以上,大大提高了同源重组的效率。重组工程技术具有完全取代传统DNA重组技术的趋势,为微生物的基因打靶技术提供了一个全新、高效手段,广泛应用在微生物菌种改良的基础理论研究和实际应用领域。

Industrial Microbe Strain Improvement and Phage Recombineering Technique

The technique of improving industrial microbe strain experienced three development stages: mutagenesis, genetic recombinant and genetic engineering. As the latest genetic engineering technique, gene targeting technique has the characteristics of precise positioning and stable heredity of new gene. With gene targeting technique, people can have destination to reform the hereditary material of microorganism, and create the new species microorganism in favor of the production. Recombineering is the technique which promotes homologous recombination between the targeting DNA using an independent phage recombina-tion system with a 40～60bp homologous sequence, and accurately modifies the target gene in chromosome DNA or the vectors in E.coli. By using of the recombineering technique, the length of homologous sequence of gene targeting vector can reach 10kb, even exceed 100kb, hence the efficiency of homologous recombination can increase hundreds times. The technique of recombineering has trend to replace the traditional recombinant DNA technique, providing the new and efficient means for the gene targeting technique, and would be widely used in the fields of the foundation theories research and practical application in improvement ofi ndustrial microbe strain.