铜绿假单胞菌IMP68超级生物被膜形成的分子机制解析

菌株自发突变形成超级生物被膜后，其环境适应能力、抵抗免疫系统和抗生素的能力都大幅提升，解析菌株形成超级生物被膜的机制将有助于防治超级生物被膜带来的危害。本项目前期从油藏环境中获得了正常菌落形态的铜绿假单胞菌IMP66和具有超级生物被膜表型的铜绿假单胞菌IMP68，序列比对发现这两株菌的WspF序列与模式菌株PAO1序列完全一致，暗示IMP68形成超级生物被膜可能存在一种有别于传统WspF自发突变的新机制。因此，本项目拟以IMP66和IMP68为研究对象，通过比较组学挖掘IMP68超级生物被膜形成的新因子，利用分子生物学手段鉴定新因子的生理功能，利用CHIP-seq、EMSA等实验技术建立新因子与c-di-GMP和胞外多糖间的调控关系，最终阐明其调控超级生物被膜形成的分子机制。项目的实施将进一步完善对铜绿假单胞菌超级生物被膜形成机制的理论认识，为开发清除超级生物被膜的有效方法提供科学依据。

Hyper-biofilm is a type of strains that significantly improves its biofilm formation ability through natural mutation, result in the formation of a thick and dense biofilm. Hyper-biofilm forming strains were characterized with high environmental adaptability, enhanced tolerance to antimicrobials and host defenses. Revealing the mechanism involved in the formation of hyper-biofilm will help prevent its adverse effects. Our previous work isolated two Pseudomonas aeruginosa strains form crude oil, in which IMP66 exhibited wild-type smooth colony morphology, while IMP68 exhibited hyper-biofilm morphology. The classical mechanism believes that the mutation of WspF is the reason for the formation of hyper-biofilm. However, the amnio acid sequences of WspF form IMP66 and IMP68 are exactly same with PAO1, suggesting that there will be new mechanisms for the formation of hyper-biofilm in IMP68. Based on our previous research works, this project will use IMP66 and IMP68 to explore the new factors involved in the formation of hyper-biofilm of IMP68 via comparative omics. Molecular biological approaches were used to identify the function of the new factor, and experimental techniques such as CHIP-seq and EMSA were used to establish the regulatory relationship between the new factor and c-di-GMP and exopolysaccharide. Finally clarify the molecular mechanism that regulates the formation of hyper-biofilm. The project will facilitate the theoretical understanding of the mechanisms in hyper-biofilm formation, and offer important scientific basis for the exploration of new treatment method in biofilm eliminating.