摘要：SummaryBacteria regulate their cellular resource allocation to enable fast growth-adaptation to a variety of environmental niches. We studied the ribosomal allocation, growth, and expression profiles of two sets of fast-growing mutants ofEscherichia coliK-12 MG1655. Mutants with only three of the seven copies of ribosomal RNA operons grew faster than the wild-type strain in minimal media and show similar phenotype to previously studied fast-growingrpoBmutants. Comparing these two different regulatory perturbations (rRNA promoters orrpoBmutations), we show how they reshape the proteome for growth with a concomitant fitness cost. The fast-growing mutants shared downregulation of hedging functions and upregulated growth functions. They showed longer diauxic shifts and reduced activity of gluconeogenic promoters during glucose-acetate shifts, suggesting reduced availability of the RNA polymerase for expressing hedging proteome. These results show that the regulation of ribosomal allocation underlies the growth/hedging phenotypes obtained from laboratory evolution experiments.Graphical abstractDisplay OmittedHighlights•Mutants with only three ribosomal operons grow faster than wild-type in minimal medium•Faster growth of mutants is achieved by increased ribosome content•Fast-growing mutants display reduced hedging expression and adaptation trade-offsBacterium; Bacteriology; Cell biology
