Nifedipine in the treatment of chilblains.

Abstract

<h3>Abstract</h3> Bacteria regulate their cellular resource allocation to enable their fast growth-adaptation to a variety of environmental niches. We studied the ribosomal allocation, growth and expression profile of two sets of fast-growing mutants of <i>Escherichia coli</i> K-12 MG1655. Mutants with 3 copies of the stronger ribosomal RNA operons grew faster than the wild-type strain in minimal media and show similar phenotype to previously studied <i>rpoB</i> mutants. All of them displayed increased ribosomal content, a longer diauxic shift and a reduced activity of the <i>aceBAK</i> operon, indicative of repressed gluconeogenic pathways. Transcriptomic profiles of fast-growing mutants showed common downregulation of hedging functions and upregulated growth functions. Proteome allocation estimations showed an increase in the growth-related proteome for fast-growing strains, but not an increased cellular budget for recombinant protein production. These results show that two different regulatory perturbations (rRNA promoters or <i>rpoB</i> mutations) increasing ribosomal allocation optimize the proteome for growth with a concomitant fitness cost. <h3>Highlights</h3> Strains with the 3 stronger ribosomal operons grow faster than the wild-type Fast-growing strains show higher ribosomal content Comparison among <i>rrn</i> and RNAP mutants shows commonalities Fast-growing strains show adaptation trade-offs Mutant’s proteome is larger and optimized for growth