Seminars – Center for Microbial Dynamics and Infection

Current schedule here. This trainee-run seminar series focused on new research in CMDI. It’s Fridays at 3pm and includes coffee and cookies. Most seminars are in College of Computing 017 for Spring 2025.

Upcoming seminar:

Abstract:

In light of climate change, sustainable agriculture is the need of the hour to fulfil the increasing food demands of an increasing population. Today, agriculture relies heavily on unsustainable and inefficient synthetic nitrogen fertilizers which have high energy and environmental footprints. The “greener” biological alternative to chemical fertilizers is biological nitrogen fixation (BNF)—the conversion of inert atmospheric nitrogen gas into bioavailable forms usable by other organisms. BNF is facilitated by the enzyme nitrogenase, which is irreversibly inactivated by oxygen. This work focuses on free-living aerobic nitrogen fixing soil bacteria such as Azotobacter vinelandii. These bacteria are reported to inhabit soil aggregates, and we hypothesize that these natural soil “microsites” offer metabolic advantages to the bacteria: the soil provides physical diffusion resistance to oxygen, allowing the bacteria to self-regulate the oxygen concentration in these microsites and fix nitrogen more efficiently. However, studying these natural soil microsites directly is challenging. Thus, we developed aqueous two-phase (ATPS) microenvironments in a 96-well plate format to mimic the physical advantages offered by the soil. Additionally, these microenvironments do not require specialized equipment, the chemical conditions in them are more reproducible and controllable than in soil, and the transparent nature of the ATPS enables the use of optical analytical techniques. This work aims to improve our understanding of BNF and soil nitrogen fixing bacteria in their natural environment. Moreover, the ATPS microenvironments, being more accessible, can potentially accelerate the rate of soil bacteria and soil bacterial community research by providing a higher throughput in vitro methodology to study bacteria in conditions resembling their natural habitats.