TY - JOUR T1 - Bacterial glycogen provides short-term benefits in changing environments JF - bioRxiv DO - 10.1101/841718 SP - 841718 AU - Karthik Sekar AU - Stephanie M. Linker AU - Jen Nguyen AU - Alix Grünhagen AU - Roman Stocker AU - Uwe Sauer Y1 - 2019/01/01 UR - http://biorxiv.org/content/early/2019/11/14/841718.1.abstract N2 - Changing nutritional conditions challenge microbes and shape their evolutionary optimization. Here we investigated the role of glycogen in dynamic physiological adaptation of Escherichia coli to fluctuating nutrients following carbon starvation using real-time metabolomics. We found significant metabolic activity remaining after the depletion of environmental glucose that was linked to a rapid utilization of intracellular glycogen. Glycogen was depleted by 80% within minutes of glucose starvation and similarly replenished within minutes of glucose availability. These fast timescales of glycogen utilization correspond to the short-term benefits that glycogen provided to cells undergoing various physiological transitions. Cells capable of utilizing glycogen exhibited shorter lag times than glycogen mutants when starved between different carbon sources. The ability to utilize glycogen was also important for the transition between planktonic and biofilm lifestyles and enabled increased glucose uptake during pulses of limited glucose availability. 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. Altogether, 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. ER -