The significance of nitrogen cost minimization in proteomes of marine microorganisms

ISME J. 2012 Jan;6(1):71-80. doi: 10.1038/ismej.2011.72. Epub 2011 Jun 23.


Marine microorganisms thrive under low levels of nitrogen (N). N cost minimization is a major selective pressure imprinted on open-ocean microorganism genomes. Here we show that amino-acid sequences from the open ocean are reduced in N, but increased in average mass compared with coastal-ocean microorganisms. Nutrient limitation exerts significant pressure on organisms supporting the trade-off between N cost minimization and increased average mass of amino acids that is a function of increased A+T codon usage. N cost minimization, especially of highly expressed proteins, reduces the total cellular N budget by 2.7-10%; this minimization in combination with reduction in genome size and cell size is an evolutionary adaptation to nutrient limitation. The biogeochemical and evolutionary precedent for these findings suggests that N limitation is a stronger selective force in the ocean than biosynthetic costs and is an important evolutionary strategy in resource-limited ecosystems.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Amino Acids / metabolism
  • Bacteria / genetics
  • Bacteria / metabolism*
  • Codon
  • Energy Metabolism
  • Genome Size
  • Nitrogen / metabolism*
  • Oceans and Seas
  • Proteome / metabolism
  • Seawater / microbiology*


  • Amino Acids
  • Codon
  • Proteome
  • Nitrogen