DiaMot: Motility of diatoms and its contribution to benthic biofilm formation

Diatoms are a group of highly diverse microalgae dominating aquatic systems and contributing to a quarter of the global primary production. In intertidal sediments, they contribute significantly to benthic biofilm communities, thereby playing an essential role in ecosystem functioning. These biofilm-forming cells thrive in a complex and dynamic microhabitat through active motility. Unlike other motile organisms, diatoms lack cilia, flagella, or the flexibility to change shape due to their rigid silicified cell walls, and hence represent a novel system for understanding cellular movement and adaptability on surfaces. This proposal focuses on three aspects that together will deliver the first complete behavioural and mechanistic characterisation of diatom motility and its role in biofilm formation.
To this end, I will (1) characterize the baseline motility of representative dominant benthic diatoms; (2) evaluate how trajectories change with perturbations (i.e., light, silicate availability, substrate topography, shear); and (3) investigate movement patterns in complex 3D substrates for in situ observation of individual and population dynamics. For this work, I have selected five representative diatom species (important constituents of common benthic biofilms) that exhibit distinct raphe morphology and vertical migration patterns. This proposal will achieve the first complete characterisation of diatom motility in both 2D and 3D scenarios. Uniquely, this work will solicit cutting-edge microscopy and computer vision technology to resolve the behavioural patterns of individuals to provide novel understanding of the biomechanics of motility and biofilm formation. The outcomes of my project are critical to predict how microscale heterogeneity present within biofilm communities can ultimately impact the global regulation of ecosystems. This fellowship will also advance my career development and act as a springboard for scientific independence.