Active pH regulation facilitates Bacillus subtilis biofilm development in a minimally buffered environment.
Active pH regulation facilitates Bacillus subtilis biofilm development in a minimally buffered environment.
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主动 pH 调节有利于枯草芽孢杆菌生物膜在最低限度缓冲的环境中发育。
DOI：
10.1128/mbio.03387-23
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发表时间：
2024
期刊：
影响因子：
6.4
通讯作者：
Prindle,Arthur
中科院分区：
文献类型：
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作者：
Tran,Peter;Lander,StephenM;Prindle,Arthur
生物膜为单个细菌提供了许多优势，但密集的细胞增殖也会产生内在的代谢挑战，包括过度酸化。由于这种pH压力可以在缓冲的实验室介质中被掩盖，例如通常用于研究枯草芽孢杆菌生物膜的MSGG，因此并不总是清楚这种生物膜如何科普最低缓冲的自然环境。在这里，我们报告如何B。枯草杆菌生物膜通过主动pH调节机制克服了这种内在的代谢挑战。具体地说，我们发现，这些生物膜可以调节其细胞外的pH值的优选的中性粒细胞的范围内，即使从酸性和碱性的初始条件，而嗜酸性细胞不能。我们将这种行为与乙酸和乙偶姻生物合成之间的动态相互作用相关联，并表明这种机制是缓冲生物膜酸化所必需的。此外，我们发现，缓冲不足的生物膜表现出失调的生物膜发展时，生长在最低限度的缓冲条件。我们的研究结果揭示了一个积极的pH调节机制在B。重要的是，已知pH影响多种细菌物种和环境背景中的微生物生长和群落动态。此外，在许多细菌物种中，快速的细胞增殖需要使用溢流代谢，这通常会导致过度酸化。然而，在被称为生物膜的细菌群落的情况下，当使用缓冲实验室培养基来稳定pH环境以实现最佳生长时，这些酸化挑战可以被掩盖。我们的研究表明，B.枯草杆菌生物膜使用主动pH调节机制来减轻与生长相关的酸化和外部pH挑战。这一发现为了解微生物群落提供了新的机会，并可能导致在缓冲实验室条件之外控制生物膜生长的新方法。
Biofilms provide individual bacteria with many advantages, yet dense cellular proliferation can also create intrinsic metabolic challenges including excessive acidification. Because such pH stress can be masked in buffered laboratory media—such as MSgg commonly used to studyBacillus subtilisbiofilms—it is not always clear how such biofilms cope with minimally buffered natural environments. Here, we report howB. subtilisbiofilms overcome this intrinsic metabolic challenge through an active pH regulation mechanism. Specifically, we find that these biofilms can modulate their extracellular pH to the preferred neutrophile range, even when starting from acidic and alkaline initial conditions, while planktonic cells cannot. We associate this behavior with dynamic interplay between acetate and acetoin biosynthesis and show that this mechanism is required to buffer against biofilm acidification. Furthermore, we find that buffering-deficient biofilms exhibit dysregulated biofilm development when grown in minimally buffered conditions. Our findings reveal an active pH regulation mechanism inB. subtilisbiofilms that could lead to new targets to control unwanted biofilm growth.IMPORTANCEpH is known to influence microbial growth and community dynamics in multiple bacterial species and environmental contexts. Furthermore, in many bacterial species, rapid cellular proliferation demands the use of overflow metabolism, which can often result in excessive acidification. However, in the case of bacterial communities known as biofilms, these acidification challenges can be masked when buffered laboratory media are employed to stabilize the pH environment for optimal growth. Our study reveals thatB. subtilisbiofilms use an active pH regulation mechanism to mitigate both growth-associated acidification and external pH challenges. This discovery provides new opportunities for understanding microbial communities and could lead to new methods for controlling biofilm growth outside of buffered laboratory conditions.