title: Large-Scale 13C flux profiling reveals conservation of the Entner-Doudoroff pathway as a glycolytic strategy among marine bacteria that use glucose.
abstract: Marine bacteria form one of the largest living surfaces on Earth, and their metabolic activity is of fundamental importance for global nutrient cycling. Here, we explored the largely unknown intracellular pathways in 25 microbes representing different classes of marine bacteria that use glucose: Alphaproteobacteria, Gammaproteobacteria, and Flavobacteriia of the Bacteriodetes phylum. We used (13)C isotope experiments to infer metabolic fluxes through their carbon core pathways. Notably, 90% of all strains studied use the Entner-Doudoroff (ED) pathway for glucose catabolism, whereas only 10% rely on the Embden-Meyerhof-Parnas (EMP) pathway. This result differed dramatically from the terrestrial model strains studied, which preferentially used the EMP pathway yielding high levels of ATP. Strains using the ED pathway exhibited a more robust resistance against the oxidative stress typically found in this environment. An important feature contributing to the preferential use of the ED pathway in the oceans could therefore be enhanced supply of NADPH through this pathway. The marine bacteria studied did not specifically rely on a distinct anaplerotic route, but the carboxylation of phosphoenolpyruvate (PEP) or pyruvate for fueling of the tricarboxylic acid (TCA) cycle was evenly distributed. The marine isolates studied belong to clades that dominate the uptake of glucose, a major carbon source for bacteria in seawater. Therefore, the ED pathway may play a significant role in the cycling of mono- and polysaccharides by bacterial communities in marine ecosystems.
authors.affiliation: Institute of Biochemical Engineering, Technical University Braunschweig, Braunschweig, Germany.
authors.forename: Arne
authors.initials: A
authors.lastname: Klingner
authors.affiliation: Institute of Biochemical Engineering, Technical University Braunschweig, Braunschweig, Germany.
authors.forename: Annekathrin
authors.initials: A
authors.lastname: Bartsch
authors.affiliation: Institute for Chemistry and Biology of the Marine Environment, University of Oldenburg, Oldenburg, Germany.
authors.forename: Marco
authors.initials: M
authors.lastname: Dogs
authors.affiliation: Helmholtz Centre for Infection Research, Research Group Microbial Communication, Braunschweig, Germany.
authors.forename: Irene
authors.initials: I
authors.lastname: Wagner-Döbler
authors.affiliation: Institute of Microbiology, Technical University Braunschweig, Braunschweig, Germany.
authors.forename: Dieter
authors.initials: D
authors.lastname: Jahn
authors.affiliation: Institute for Chemistry and Biology of the Marine Environment, University of Oldenburg, Oldenburg, Germany.
authors.forename: Meinhard
authors.initials: M
authors.lastname: Simon
authors.affiliation: Institute for Chemistry and Biology of the Marine Environment, University of Oldenburg, Oldenburg, Germany.
authors.forename: Thorsten
authors.initials: T
authors.lastname: Brinkhoff
authors.affiliation: Institute of Systems Biotechnology, Saarland University, Saarbrücken, Germany.
authors.forename: Judith
authors.initials: J
authors.lastname: Becker
authors.affiliation: Institute of Systems Biotechnology, Saarland University, Saarbrücken, Germany christoph.wittmann@uni-saarland.de.
authors.forename: Christoph
authors.identifier: http://orcid.org/0000-0002-7952-985X
authors.initials: C
authors.lastname: Wittmann
mesh_terms: D059001:Aquatic Organisms / Q000235:genetics / Q000378:metabolism*; D001419:Bacteria / Q000235:genetics / Q000378:metabolism*; D002247:Carbon Isotopes / Q000378:metabolism*; D002952:Citric Acid Cycle; D005947:Glucose / Q000378:metabolism*; D006019:Glycolysis; D007553:Isotope Labeling; D064688:Metabolic Flux Analysis; D008969:Molecular Sequence Data; D010728:Phosphoenolpyruvate / Q000378:metabolism; D019289:Pyruvic Acid / Q000378:metabolism; D017422:Sequence Analysis, DNA
chemical_list: D002247:Carbon Isotopes; D010728:Phosphoenolpyruvate; D019289:Pyruvic Acid; D005947:Glucose