Bacterial Glycogen Provides Short-Term Benefits in Changing Environments
Changing nutritional conditions challenge microbes and shape their evolutionary optimization. In an "Applied Environmental Microbiology" paper researchers from the Sauer lab (IMSB) investigated the role of glycogen in dynamic physiological adaptation of Escherichia coli to fluctuating nutrients following carbon starvation using real-time metabolomics.
Nothing is constant in life and microbes in particular have to adapt to frequent and rapid environmental changes. In collaboration with the Stocker lab in the ETH department of Environmental Engineering, the Sauer lab demonstrated that the internal storage polymer glycogen plays a crucial role for such dynamic adaptations by using real-time metabolomics and single cell imaging. Glycogen depletes within minutes of glucose starvation and similarly replenishes within minutes of glucose availability. Cells capable of utilizing glycogen exhibited shorter lag times than glycogen mutants when starved between different carbon sources. While wild-type and mutant strains exhibited comparable growth rates in steady environments, mutants deficient in glycogen utilization grew more poorly in environments that fluctuated on minute-scales between carbon availability and starvation. These results highlight an underappreciated role of glycogen to rapidly provide carbon and energy in changing environments, thereby increasing survival and competition capabilities in fluctuating and nutrient poor conditions.
Link to the publication in external page Applied Environmental Microbiology.