Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore.
School of Biological Sciences, Nanyang Technological University, Singapore, Singapore.
Front Cell Infect Microbiol. 2021 Mar 18;11:646991. doi: 10.3389/fcimb.2021.646991. eCollection 2021.
Bacterial biofilms are important medically, environmentally and industrially and there is a need to understand the processes that govern functional synergy and dynamics of species within biofilm communities. Here, we have used a model, mixed-species biofilm community comprised of PAO1, Pf-5 and KP1. This biofilm community displays higher biomass and increased resilience to antimicrobial stress conditions such as sodium dodecyl sulfate and tobramycin, compared to monospecies biofilm populations. is present at low proportions in the community and yet, it plays a critical role in community function, suggesting it acts as a keystone species in this community. To determine the factors that regulate community composition, we focused on because of its pronounced impact on community structure and function. Specifically, we evaluated the role of the N-acyl homoserine lactone (AHL) dependent quorum sensing (QS) system of PAO1, which regulates group behaviors including biofilm formation and the production of effector molecules. We found that mixed species biofilms containing QS mutants had significantly altered proportions of and populations compared to mixed species biofilms with the wild type . Similarly, inactivation of QS effector genes, e.g. and , also governed the relative species proportions. While the absence of QS did not alter the proportions of the two species in dual species biofilms of and , it resulted in significantly lower proportions of in dual species biofilms with . These observations suggest that QS plays an important role in modulating community biofilm structure and physiology and affects interspecific interactions.
细菌生物膜在医学、环境和工业方面都具有重要意义，因此需要了解控制生物膜群落中物种功能协同和动态的过程。在这里，我们使用了一个模型，即由 PAO1、Pf-5 和 KP1 组成的混合物种生物膜群落。与单物种生物膜群体相比，该生物膜群落显示出更高的生物量和对十二烷基硫酸钠和妥布霉素等抗菌应激条件的更强抵抗力。 在群落中的比例较低，但它在群落功能中起着关键作用，表明它在该群落中起着关键物种的作用。为了确定调节群落组成的因素，我们专注于 ，因为它对群落结构和功能有明显的影响。具体来说，我们评估了 PAO1 的 N-酰基高丝氨酸内酯（AHL）依赖性群体感应（QS）系统的作用，该系统调节包括生物膜形成和效应分子产生在内的群体行为。我们发现，含有 QS 突变体的混合物种生物膜与含有野生型的混合物种生物膜相比， 的和 的种群比例有明显改变。同样，QS 效应基因（如 和 ）的失活也控制了相对物种比例。虽然 QS 的缺失没有改变 和 双物种生物膜中两种物种的比例，但它导致 和 双物种生物膜中 的比例显著降低。这些观察结果表明，QS 在调节群落生物膜结构和生理学以及影响种间相互作用方面起着重要作用。
