Theo Gervais

All Publications

• <i>E. coli</i> prepares for starvation by dramatically remodeling its proteome in the first hours after loss of nutrients MOLECULAR SYSTEMS BIOLOGY Gervais, T., Kscheschinski, B., Mell, M., Goepfert, N., van Nimwegen, E., Julou, T. 2026

  Abstract

  Although in the wild bacteria likely spend most of their time deprived of nutrients and slowly starving to death, very little is known about how bacteria adapt their phenotype to starvation. Here we combine microfluidics with quantitative fluorescence microscopy of transcriptional reporters to comprehensively quantify growth and gene expression at the single-cell level in E. coli during carbon starvation. We find that all cells immediately stop growing upon loss of carbon source and that almost all remain alive for over 30 hours. Furthermore, entry into starvation triggers a dynamic expression program that is remarkably homogeneous across single cells, but highly variable across genes, causing dramatic remodeling of the proteome early in starvation. We further show that, as protein production and the rate of protein degradation both decay approximately exponentially, protein concentrations become essentially 'frozen' after the first 5 to 10 hours, setting phenotypes for several days of starvation. Finally, using experiments in which gene expression is inhibited for different periods, we show that protein production in the first 5 hours is crucial for protecting cells from stresses late in starvation.

  View details for DOI 10.1038/s44320-026-00226-5

  View details for Web of Science ID 001808439900001

  View details for PubMedID 42387107

  View details for PubMedCentralID 10277933

• Growth rate controls the sensitivity of gene regulatory circuits. Science advances Julou, T., Gervais, T., de Groot, D., van Nimwegen, E. 2025; 11 (17): eadu9279

  Abstract

  Microbes adapt to their environments using gene regulatory switches that sense environmental signals and induce target genes in response. Mathematical modeling predicts that, because growth rate sets the intracellular dilution rate, the sensitivity of regulatory switches to chemical cues systematically decreases with growth rate. We experimentally validate that the concentration of inducer required to activate E. coli's lac operon increases quadratically with growth rate when varying nutrients but is invariant when varying growth rate through translation inhibition. We further establish that this growth-coupled sensitivity (GCS) allows bacteria to implement concentration-dependent sugar preferences, in which a new carbon source is used only if its concentration is sufficient to improve upon the current growth rate. Using microfluidics in combination with time-lapse microscopy, we validate this prediction at the single-cell level using mixtures of glucose and lactose. Overall, GCS causes cells to automatically become more sensitive to environmental signals when their growth rate decreases.

  View details for DOI 10.1126/sciadv.adu9279

  View details for PubMedID 40279435

  View details for PubMedCentralID PMC12024649