巨大芽孢杆菌Bacillus megaterium1301的转座诱变

THE MUTANTS OF BACILLUS MEGATERIUM1301 WITH TRANSPOSON

本研究通过原生质体法、电击法和转座诱导方法,建立了携带转座子Tn917的质粒pTV1对野生巨大芽孢杆菌B1301菌株的转化体系与转座子突变技术,获得1000多个转座插入突变子。通过细胞分裂素生物测试法对这些突变子进行测定,筛选到2个突变子B1301-6与B1301-22。B1301-22突变子分泌的细胞分裂素比B1301有显著提高,而B1301-6突变子分必和细胞分裂比1301有显著降低。抑菌试验结果表明这2个细胞分裂素产量发生改变的突变子抑制率显著低于野生菌株,说明转座子Tn917的插入不仅使野生B1301菌株编码控制细胞分裂素产量的基因发生了改变,同时也改变了与编码抑菌功能相关的基因也受到了影响。

Bacillus megaterium B1301 produces cytokinin. A mutagenesis technique system of B. megaterium 1301was generated by transposon Tn917 mutageneisis, and the functional gene encoding the antipeptide was knocked off by the tansponson. In this study, B. mutageneisis1301 was transformed with plasmidp TV1 carrying transponson Tn917 by protoplast and electrotransformation methods. Transformed B1301 strains were screened resistance against chloromycetin, erythromycin and lincomycin. By the transposon Tn 917 mediated insertional mutagenesis technique, the transponson Tn 917 successfully inserted the genome of B 1301 and more 1000 mutants wete screened that were resistant to erythromycin and lincomycin but susceptible to chloromycetin. Two transposons was obtained through biologic method of cytekinin, which was B1301 -6 and B1301 -22. The production of cytokinin in B1301 -22 is more than＇ in B1301 and B1301 -6 is less than in B1301. The inhibiting effect of two transposons was obvious less than B1301 by antibiolotic experiment. The result suugests that the insertion of Tng17 not only changed the functional gene encoding cytokinin but also restrained the functional gene encoding antibiosis.