关键词: 施氏假单胞菌, 环二鸟苷酸, 生物膜形成, 磷酸二酯酶, bifA基因

Abstract: Cyclic diguanolate monophosphate (c-di-GMP) is an important bacterial second messenger molecule which was involved in the regulation of various cellular processes. C-di-GMP is synthesized by the diguanylate cyclases (DGCs) from two GTP molecules, and hydrolyzed by the phosphodiesterases(PDEs). A bifA gene was reported to be the c-di-GMP degradation gene in Pseudomonas aeruginosa, and was proposed to involved in adjusting intracellular c-di-GMP concentration. In this work, the role of bifA in c-di-GMP degradation and biofilm formation was investigated in Pseudomonas stutzeri A1501. It was found that the deletion of the bifA gene resulted in an accumulation of intracellular c-di-GMP, and enhanced the capability of biofilm formation in A1501. In addition, excess c-di-GMP produced in the bifA mutant strain leaded swimming motility to repress. The results suggested that bifA is a key gene for c-di-GMP degradation. And the bifA affected the biofilm formation, swimming motility and other physiological phenotypes by regulating intracellular c-di-GMP concentration level. The results provided a theoretical basis for signal transduction and environmental adaptation of root-associate nitrogen-fixing bacteria.

Key words: Pseudomonas stutzeri, c-di-GMP, biofilm formation, phosphodiesterase, bifA gene