【摘要】 荧光假单胞菌M1 8对多种植物病原真菌具有显著的抑制作用。荧光假单胞菌(Pseuclomonesfluo rescens)M1 8能同时合成吩嗪 1 羧酸 (PCA)和藤黄绿菌素 (Plt)两种抗生素。从M1 8的基因组中克隆了rpoD基因 ,其相应的氨基酸序列与荧光假单胞菌CHAO中RpoD蛋白的氨基酸序列完全相同。利用基因重组技术和大肠杆菌 荧光假单胞菌穿梭质粒pME60 32 ,将rpoD置于强启动子Ptac的控制下 ,导入M1 8菌株。发现经重组质粒转化的M1 8,与对照相比 ,培养基中PCA和Plt开始累积的时间分别提前 4h和 8h ,积累量提高 1倍和 6倍。更多还原

【Abstract】 Fluorescent pseudomonas M18, one of plant growth promoting rhizobacteria which can inhibit growth of several phytopathogenes, produces several secondary metabolites including antibiotics phenazine-1-carboxylic acid (PCA) and pyoluteorin (Plt). The rpoD gene encoding the housekee- ping sigma factor σ 70 was cloned and sequenced from M18. Through sequencing and homogeneous comparison, the deduced RpoD amino acid sequence between M18 strain and Pseudomonas fluorescens CHAO shows 100% identity. It indicates that rpoD gene is very conserved in different members of fluorescent pseudomonads. The rpoD gene was placed downstream of the constitutive P tac promoter in the shuttle vector pME6032 between E.coli and Pseudomonas fluorescens and the recombinant plasmid was introduced into M18. It was found that the time of both PCA and Plt began to accumulate was 4 and 8 hours earlier and the yield of these antibiotics was increased one and six times more respectively in M18 in comparison with the control.更多还原