title: Temperature dependences of growth rates and carrying capacities of marine bacteria depart from metabolic theoretical predictions.
abstract: Using the metabolic theory of ecology (MTE) framework, we evaluated over a whole annual cycle the monthly responses to temperature of the growth rates (μ) and carrying capacities (K) of heterotrophic bacterioplankton at a temperate coastal site. We used experimental incubations spanning 6ºC with bacterial physiological groups identified by flow cytometry according to membrane integrity (live), nucleic acid content (HNA and LNA) and respiratory activity (CTC+). The temperature dependence of μ at the exponential phase of growth was summarized by the activation energy (E), which was variable (-0.52 to 0.72 eV) but followed a seasonal pattern, only reaching the hypothesized value for aerobic heterotrophs of 0.65 eV during the spring bloom for the most active bacterial groups (live, HNA, CTC+). K (i.e. maximum experimental abundance) peaked at 4 × 10(6) cells mL(-1) and generally covaried with μ but, contrary to MTE predictions, it did not decrease consistently with temperature. In the case of live cells, the responses of μ and K to temperature were positively correlated and related to seasonal changes in substrate availability, indicating that the responses of bacteria to warming are far from homogeneous and poorly explained by MTE at our site.
authors.affiliation: Centro Oceanográfico de Gijón/Xixón, Instituto Español de Oceanografía, 33212 Gijón/Xixón, Asturias, Spain tamara.huete@gmail.com.
authors.forename: Tamara Megan
authors.initials: TM
authors.lastname: Huete-Stauffer
authors.affiliation: Centro Oceanográfico de Gijón/Xixón, Instituto Español de Oceanografía, 33212 Gijón/Xixón, Asturias, Spain.
authors.forename: Nestor
authors.initials: N
authors.lastname: Arandia-Gorostidi
authors.affiliation: Centro Oceanográfico de Gijón/Xixón, Instituto Español de Oceanografía, 33212 Gijón/Xixón, Asturias, Spain.
authors.forename: Laura
authors.initials: L
authors.lastname: Díaz-Pérez
authors.affiliation: Centro Oceanográfico de Gijón/Xixón, Instituto Español de Oceanografía, 33212 Gijón/Xixón, Asturias, Spain Red Sea Research Center, Division of Biological and Environmental Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia.
authors.forename: Xosé Anxelu G
authors.initials: XA
authors.lastname: Morán
mesh_terms: D001419:Bacteria / Q000254:growth & development* / Q000378:metabolism; D018407:Bacterial Physiological Phenomena; D003247:Conservation of Natural Resources; D004463:Ecology; D052836:Heterotrophic Processes; D010933:Plankton / Q000254:growth & development* / Q000378:metabolism; D012621:Seasons; D013696:Temperature
keywords: activation energy; carrying capacity; coastal ocean; flow cytometry; marine bacteria; metabolic theory of ecology