Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore.
School of Biological Sciences, Nanyang Technological University, Singapore, Singapore.
NPJ Biofilms Microbiomes. 2024 Sep 28;10(1):91. doi: 10.1038/s41522-024-00546-0.
Biofilms in nature often exist as communities. In this study, an experimental mixed-species community consisting of Pseudomonas aeruginosa, Pseudomonas protegens and Klebsiella pneumoniae was used to investigate how AI-2 transporters affect interspecies interactions and composition. The K. pneumoniae lsrB/lsrD deletion mutants had a 10-25-fold higher concentration of extracellular AI-2 compared to the wild-type. Although these deletion mutants produced monospecies biofilms of similar biomass, the substitution of these mutants for the parental strain significantly altered composition. Dual-species biofilm assays demonstrated that the changes in composition were due to the cumulative effect of pairwise interactions. It was further revealed that K. pneumoniae being present physically in the consortium was important in AI-2 mediating composition in the consortium, and that AI-2 transporters were crucial in achieving maximum biomass in the community. In conclusion, these findings demonstrate that AI-2 transporters mediate interspecies interactions and is important in maintaining the compositional equilibrium of the community.
自然界中的生物膜通常以群落的形式存在。在本研究中，使用了一种由铜绿假单胞菌、保护菌和肺炎克雷伯菌组成的实验混合种群落，以研究 AI-2 转运蛋白如何影响种间相互作用和组成。与野生型相比，肺炎克雷伯菌的 lsrB/lsrD 缺失突变体的细胞外 AI-2 浓度高 10-25 倍。尽管这些缺失突变体形成了相似生物量的单物种生物膜，但这些突变体替代亲本菌株会显著改变群落组成。双物种生物膜测定表明，组成的变化是由于成对相互作用的累积效应。进一步揭示了在群落中，K. pneumoniae 以物理方式存在于联合体中，在 AI-2 介导联合体组成方面很重要，而 AI-2 转运蛋白对于在联合体中实现最大生物量至关重要。总之，这些发现表明 AI-2 转运蛋白介导种间相互作用，对维持群落的组成平衡很重要。
