Suckjoon Jun, Ph.D.

Research

My lab studies the fundamental quantitative principles underlying microbial cell physiology. In the past, we invented the microfluidic “mother machine”; explained the half-century-old relationship between average cell size and nutrient-imposed growth rate discovered by Schaechter, Maaløe, and Kjeldgaard (1959); and coined and uncovered the “adder principle” of cell-size control and its mechanistic basis. Our current goal is to understand how the processes of the central dogma intersect at the single-cell level across the three domains of life. To this end, we are developing an autonomous discovery engine that brings insights from economics into cellular physiology—an approach we call econophysiology—aiming to go beyond the framework established by studies of E. coli over the past 50 years.

As Innovation Fund investigators, Suckjoon Jun, Ph.D., and Michael J. Rust, Ph.D., are joining forces to explore how cyanobacteria regulate growth and allocate cellular resources in fluctuating environments. Their goal is to uncover fundamental principles of physiological control that go beyond what has been learned from heterotrophic bacteria such as Escherichia coli and may extend to eukaryotic systems. To achieve this, the team will first adapt quantitative growth analysis methods developed in the Jun lab to define growth laws governing cyanobacteria under constant conditions. They will then extend this analysis to cycling light-dark environments and, using circadian clock mutants developed in the Rust lab, determine how internal rhythmicity influences growth rules. Finally, they will employ high-throughput sequencing to identify trade-offs between growth rate maximization and stress tolerance and uncover their mechanistic basis. Together, this work will broaden our understanding of the universal principles underlying cellular growth that extend beyond E. coli to diverse life forms.