Environmental Science and Engineering Seminar

Microbes in porous media systems are commonly found as aggregates consisting of cells, organic and inorganic matters, and water, known as bioaggregates. Bioaggregates are known to cause rapid clogging of both natural and engineered porous media systems. However, the underlying biophysical mechanisms that cause bioaggregation have been unclear. In the first part of my talk, I will show how we combined microfluidics experiments and numerical simulations to elucidate the origin of bioaggregation in porous media systems. We show that the rapid bioaggregation is driven by the interplay of the viscoelastic nature of biomass and hydrodynamic conditions at pore throats [Lee et al., PNAS, 2023]. We further show that the morphology transition from aggregates to biofilm streamers is induced by pore-throat flows and use this knowledge to control bioclogging. In the second part of my talk, I will present our recent work showing the tremendous potential of a fungal strain for removal of trapped oil. We show that fungi can actively penetrate porous materials and invade different fluid phases using a variety of chemical and physical tools. We visually demonstrate the remarkable removal of trapped oil in low permeability regions by a branching fungus and discuss underlying mechanisms.