Biofilms in fluids: flow-driven assembly dynamics and rheology

Abstract: Biofilms are aggregates of microorganisms in which cells are embedded in a self-secreted matrix of polymeric substances, which protects the microbial community from chemical and mechanical insults, thus favoring its survival and evolutionary success. As a result, biofilms have a crucial impact in environmental, industrial, and medical settings. Despite this, a mechanistic understanding of how the fluid environment shapes properties is lacking.

We investigate how fluid dynamics conditions drive biofilm assembly and the emergence of distinctive morphological and mechanical properties. Flow can influence several stages of biofilm formation, starting from surface colonization. On curved surfaces, flow can promote the formation of colonization hotspots, which lately impact biofilm formation. Surface geometry, flow shear, fluid rheology, and bacterial phenotype are the parameters controlling surface colonization. During biofilm maturation, the interplay between biological functions and flow controls biofilm morphology and rheology, ultimately affecting biofilms' physiological protective function. By shedding light on this interplay, we can control biofilm development, showing the prominent role that physics can play in developing novel antifouling strategies.