Cohesive extracellular polymeric substances (EPS) generated by microorganisms abundant on Earth are regarded as bed “stabilizers” increasing the erosion threshold in sedimentary systems. However, most observations of this phenomenon have been taken under steady flow conditions. In contrast, we present how EPS affect the bed movement under wave action, showing a destabilization of the system. We demonstrate a complex behavior of the biosedimentary deposits, which encompasses liquefaction, mass motion, varying bed formations and erosion, depending on the amount of EPS present. Small quantities of EPS induce higher mobility of the sediments, liquefying an otherwise stable bed. Bed with larger quantities of EPS undergoes a synchronized mechanical oscillation. Our analysis clarifies how biological cohesion can potentially put coastal wetlands at risk by increasing their vulnerability to waves. These findings lead to a revised understanding of the different roles played by microbial life, and their importance as mediators of seabed mobility.

中文翻译：

---

生物凝聚力：波浪作用下床层运动的设计者

由地球上丰富的微生物产生的粘性细胞外聚合物（EPS）被认为是增加沉积系统中侵蚀阈值的“稳定剂”。但是，对这种现象的大多数观察是在稳定流动条件下进行的。相反，我们介绍了EPS如何在波浪作用下如何影响床的运动，从而显示了系统的不稳定。我们证明了生物沉积沉积物的复杂行为，包括液化，质量运动，变化的床层形成和侵蚀，这取决于存在的EPS量。少量EPS会引起沉积物更高的迁移率，从而液化原本稳定的床层。带有大量EPS的床会经历同步的机械振荡。我们的分析阐明了生物凝聚力如何通过增加其对海浪的脆弱性而可能使沿海湿地处于危险之中。这些发现导致人们对微生物生命所起的不同作用及其作为海床迁移介质的重要性的认识有了新的认识。