(584h) Observing Bacterial Dynamics in Transparent Soil Microcosms

Observing the dynamics of soil-dwelling bacteria in their environment is pivotal for our understanding of microbial survival and resource utilization. Soil presents a complex and heterogeneous environment which forces bacteria to adapt their growth and motility based on the morphology of their surroundings. Traditional methods of studying bacterial behavior in soils are inaccessible due to the opacity of natural soil matrices. To address this challenge, we create a transparent porous medium that emulates the structural heterogeneity found in natural soils. Unlike previous studies employing hydrogel-based porous media, our model incorporates cryolite, an impermeable mineral with a refractive index equivalent to water. This enables us to directly visualize bacteria using confocal microscopy in a structured environment that more accurately mimics soils by confining both the microbes and their nutrients. These cryolite-based porous media provide a minimalistic microcosm to test microbial responses to physicochemical changes such as varying soil texture and chemical environment. Our results provide insights into bacterial proliferation and chemotactic migration within soil-like environments, bypassing the issue of opacity of natural soils.