Pseudomonas pseudoalcaligenes B50铁载体合成相关基因pyrD的克隆与功能分析

Cloning and Functional Analysis of pyrD Gene Involved in Siderophores Biosynthesis in Pseudomonas pseudoalcaligenes B50

从棉花根际分离的一株细菌B50在低铁条件下可以产生铁载体。通过形态学特征、生理生化特征及其16SrDNA序列分析,将其鉴定为Pseudomonas pseudoalcaligenes。采用三亲本杂交的方法将转座子Tn5-1063a(含luxAB)导入B50中,进行转座子插入诱变,获得突变株。用TAIL-PCR方法得到与铁吸收有关的pyrD基因序列。通过互补实验验证pyrD与铁载体的合成有关。Pseudomonas pseudoalcaligenes能够产生铁载体属于首次报道。

In order to study the mechanism of bacteria producing siderophore, B50 was isolated from the cotton rhizosphere. The strain BS0 can produce siderophore under iron-limiting conditions. It was identified as Pseudomonas pseudoalcaligenes based on its morphological, physical-chemical characteristics and 16S rDNA sequence. Mutants of B50 were obtained through conjugation. The pyrD gene was cloned from the mutant deficient in siderophores synthesis by TAIL-PCR （Thermal asymmetric interlaced）. The pyrD gene is required for the synthesis of dihydroorotate which is a predecessor of deoxyquinoline. Deoxyquinoline was the important part of several siderophores. This is the first report that the Pseudomonas pseudoalcaligenes can produce siderophore.