Stream Biofilm and Ecosystem Research Laboratory, Ecole Polytechnique Fédérale de Lausanne, CH-1015, Lausanne, Switzerland.
Institute of Earth Sciences, University of Lausanne, CH-1015, Lausanne, Switzerland.
ISME J. 2019 Jul;13(7):1700-1710. doi: 10.1038/s41396-019-0381-4. Epub 2019 Mar 4.
Biofilms regulate critical processes in porous ecosystems. However, the biophysical underpinnings of the ecological success of these biofilms are poorly understood. Combining experiments with fluidic devices, sequencing and modeling, we reveal that architectural plasticity enhances space exploitation by multispecies biofilms in porous environments. Biofilms consistently differentiated into an annular base biofilm coating the grains and into streamers protruding from the grains into the pore space. Although different flow-related processes governed the differentiation of these architectures, both BB and streamers were composed of similar bacterial assemblages. This is evidence for architectural plasticity. Architectural plasticity allowed for complementary use of the space provided by the grain-pore complexes, which increased biofilm carrying capacity at the larger scale of the porous system. This increase comes potentially at the cost of a tradeoff. Contrasting time scales of oxygen replenishment and consumption, we show that streamers locally inhibit the growth of the BB downstream from the grains. Our study provides first insights into the biophysical underpinnings to the success of multispecies biofilms in porous environments.
生物膜调节多孔生态系统中的关键过程。然而，这些生物膜在生态学上取得成功的生物物理基础仍知之甚少。我们结合使用流体设备、测序和建模的实验方法，揭示了结构可塑性增强了多物种生物膜在多孔环境中对空间的利用。生物膜始终分化为覆盖颗粒的环形基础生物膜和从颗粒突出到孔隙空间的流状生物膜。尽管不同的与流动相关的过程控制了这些结构的分化，但 BB 和流状生物膜都由相似的细菌组合组成。这证明了结构可塑性的存在。结构可塑性允许对颗粒-孔隙复合体提供的空间进行互补利用，从而在多孔系统的较大尺度上增加生物膜的承载能力。这种增加可能是以牺牲为代价的。我们展示了，在氧补充和消耗的时间尺度上存在差异，流状生物膜在颗粒下游的 BB 处局部抑制了其生长。我们的研究首次为多物种生物膜在多孔环境中取得成功的生物物理基础提供了深入了解。
