费氏中华根瘤菌ntrBC基因突变株的构建及其特性

Construction and Characterization of ntrB^- and ntrC^- Mutants of Sinorhizobium fredii

从费氏中华根瘤菌(Sinorhizobium fredii)HN01基因文库的重组质粒pGXHN300上获得ntrB、ntrC基因完整序列.通过自杀质粒pK18mob同源单交换的方法,分别获得了HN01菌株的ntrB和ntrC基因的突变株GXHNB、GXHNC.功能检测证明GXHNB、GXHNC能以硝酸盐为唯一氮源进行正常生长,但不能以铵源作为唯一氮源进行正常生长.

The ntrB and ntrC genes of Sinorhizobium fredii strain HN01 were obtained from recombinant plasmid pGXHN300. The ntrB^- and ntrC^- mutants, named GXHNB and GXHNC, were constructed through homologous recombination caused by a single crossover event. Compared with parent strain HN01, the GXHNB and GXHNC were able to grow on the medium with nitrate as the sole nitrogen source, but grew weakly on the medium with ammonium as the sole nitrogen source. Fig 4, Tab 1, Ref 15 .