title: Temperature affects stoichiometry and biochemical composition of Escherichia coli.
abstract: Temperature is a master variable controlling biochemical processes in organisms, and its effects are manifested on many organizational levels in organisms and ecosystems. We examined the effects of temperature on the biochemical composition and stoichiometry of a model heterotrophic bacterium, Escherichia coli K-12, held at constant growth rate in chemostats. Increasing temperature led to increased cellular organic carbon (C) and organic nitrogen (N) with decreased phosphorus (P) content, leading to increased C/P and N/P biomass ratios. P content was related to cellular RNA, which is P-rich (9-10% by weight) and nonnucleic acid P (presumably composed of mostly phospholipids, intracellular phosphate, and polyphosphate). These results indicate that E. coli allocates an increased proportion of its P cell quota toward assembly (ribosomes) at low temperatures and an increasing proportion toward resource acquisition machinery (membranes) at higher temperatures. If these results are relevant to the behavior of prokaryotic heterotrophs in natural settings (the gut, soils, lakes, oceans, etc.), it suggests greater nutrient regeneration and less microbial nutrient retention as temperatures increase.
authors.affiliation: Department of Ecology, Evolution and Behavior, University of Minnesota, 1987 Upper Buford Circle, St. Paul, MN 55108, USA. cotne002@umn.edu
authors.forename: James B
authors.initials: JB
authors.lastname: Cotner
authors.forename: Wataru
authors.initials: W
authors.lastname: Makino
authors.forename: Bopaiah A
authors.initials: BA
authors.lastname: Biddanda
mesh_terms: D018533:Biomass; D002244:Carbon / Q000378:metabolism; D017753:Ecosystem; D004926:Escherichia coli / Q000254:growth & development* / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism; D010758:Phosphorus / Q000378:metabolism; D012329:RNA, Bacterial / Q000378:metabolism; D013696:Temperature
chemical_list: D012329:RNA, Bacterial; D010758:Phosphorus; D002244:Carbon; D009584:Nitrogen