Real-time detection of central carbon metabolism in living Escherichia coli and its response to perturbations

The direct tracking of cellular reactions in vivo has been facilitated with recent technologies that strongly enhance NMR signals in substrates of interest. This methodology can be used to assay intracellular reactions that occur within seconds to few minutes, as the NMR signal enhancement typically fades on this time scale. Here, we show that the enhancement of 13C nuclear spin polarization in deuterated glucose allows to directly follow the flux of glucose signal through rather extended reaction networks of central carbon metabolism in living Escherichia coli. Alterations in central carbon metabolism depending on the growth phase or upon chemical perturbations are visualized with minimal data processing by instantaneous observation of cellular reactions.