Choi Kyung Soon, Veeraragouda Yaligara, Cho Kyung Mi, Lee Soo O, Jo Geuk Rae, Cho Kyungyun, Lee Kyoung
Department of Microbiology, Changwon National University, Changwon, Republic of Korea.
J Microbiol. 2007 Dec;45(6):492-8.
GacS and GacA proteins form a two component signal transduction system in bacteria. Here, Tn5 transposon gacS and gacA (Gac) mutants of Pseudomonas sp. KL28, an alkylphenol degrader, were isolated by selecting for smooth colonies of strain KL28. The mutants exhibited reduced ability to migrate on a solid surface. This surface motility does not require the action of flagella unlike the well-studied swarming motility of other Pseudomonas sp. The Gac mutants also showed reduced levels of biofilm and pellicle formation in liquid culture. In addition, compared to the wild type KL28 strain, these mutants were more resistant to high concentrations of m-cresol but were more sensitive to H2O2, which are characteristics that they share with an rpoS mutant. These results indicate that the Gac regulatory cascade in strain KL28 positively controls wrinkling morphology, biofilm formation, surface translocation and H2O2 resistance, which are important traits for its capacity to survive in particular niches.
GacS和GacA蛋白在细菌中形成双组分信号转导系统。在此，通过筛选菌株KL28的光滑菌落，分离出了烷基酚降解菌假单胞菌属KL28的Tn5转座子gacS和gacA（Gac）突变体。这些突变体在固体表面上的迁移能力降低。与其他假单胞菌属中研究充分的群体运动不同，这种表面运动不需要鞭毛的作用。Gac突变体在液体培养中还表现出生物膜和菌膜形成水平降低。此外，与野生型KL28菌株相比，这些突变体对高浓度间甲酚更具抗性，但对H2O2更敏感，这些是它们与rpoS突变体共有的特征。这些结果表明，菌株KL28中的Gac调控级联正向控制皱纹形态、生物膜形成、表面易位和H2O2抗性，这些是其在特定生态位中生存能力的重要特征。
