Sack Lunch Seminar (SLS)

Marine Microbes in Motion





A fundamental determinant of marine microbial ecology is motion: of microbes, of fluid, of resources. Yet, aquatic microbial ecology is often studied 'in bulk', without consideration of the appropriate spatial and temporal scales of motion. I will illustrate the broad implications of motion and motility in the microbial world using a combination of microfluidic experiments and mathematical modeling, focusing on three processes: (i) chemotaxis confers significant foraging advantage to motile bacteria; (ii) motility can be disrupted by fluid shear, causing intense cell accumulations like thin phytoplankton layers; and (iii) stirring and mixing of nutrient patches by small-scale turbulence affects microbial nutrient uptake. Our results suggest that the complex interplay between motility, fluid flow and spatial resource heterogeneity can fundamentally affect microbial life in aquatic systems. This, in turn, has important repercussions on biogeochemical cycles and trophic dynamics in the Ocean.