title: Physiology of Geobacter metallireducens under excess and limitation of electron donors. Part II. Mimicking environmental conditions during cultivation in retentostats.
abstract: The strict anaerobe Geobacter metallireducens was cultivated in retentostats under acetate and acetate plus benzoate limitation in the presence of Fe(III) citrate in order to investigate its physiology under close to natural conditions. Growth rates below 0.003h(-1) were achieved in the course of cultivation. A nano-liquid chromatography-tandem mass spectrometry-based proteomic approach (nano-LC-MS/MS) with subsequent label-free quantification was performed on proteins extracted from cells sampled at different time points during retentostat cultivation. Proteins detected at low (0.002h(-1)) and high (0.06h(-1)) growth rates were compared between corresponding growth conditions (acetate or acetate plus benzoate). Carbon limitation significantly increased the abundances of several catabolic proteins involved in the degradation of substrates not present in the medium (ethanol, butyrate, fatty acids, and aromatic compounds). Growth rate-specific physiology was reflected in the changed abundances of energy-, chemotaxis-, oxidative stress-, and transport-related proteins. Mimicking natural conditions by extremely slow bacterial growth allowed to show how G. metallireducens optimized its physiology in order to survive in its natural habitats, since it was prepared to consume several carbon sources simultaneously and to withstand various environmental stresses.
authors.affiliation: Institute of Groundwater Ecology, Helmholtz Zentrum München, Ingolstädter Landstraße 1, 85764 Neuherberg, Germany.
authors.forename: Sviatlana
authors.initials: S
authors.lastname: Marozava
authors.affiliation: Department of Molecular Cell Physiology, Faculty of Earth and Life Sciences, VU University Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands.
authors.forename: Wilfred F M
authors.initials: WF
authors.lastname: Röling
authors.affiliation: Department Proteomics, Helmholtz Center for Environmental Research - UFZ, Permoserstraße 15, 04318 Leipzig, Germany; Institute of Animal Nutrition, University of Hohenheim, Emil-Wolff-Str. 10, 70599 Stuttgart, Germany.
authors.forename: Jana
authors.initials: J
authors.lastname: Seifert
authors.affiliation: Teaching and Research Unit Bioinformatic, Institut für Informatik, Ludwig-Maximilians-Universität München, Amalienstr. 17, 80333 Munich, Germany.
authors.forename: Robert
authors.initials: R
authors.lastname: Küffner
authors.affiliation: Department Proteomics, Helmholtz Center for Environmental Research - UFZ, Permoserstraße 15, 04318 Leipzig, Germany; Department Metabolomics, Helmholtz Center for Environmental Research - UFZ, Permoserstraße 15, 04318 Leipzig, Germany; Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, Sohngaardsholmsvej 49, DK-9000 Aalborg, Denmark.
authors.forename: Martin
authors.initials: M
authors.lastname: von Bergen
authors.affiliation: Institute of Groundwater Ecology, Helmholtz Zentrum München, Ingolstädter Landstraße 1, 85764 Neuherberg, Germany. Electronic address: rainer.meckenstock@helmholtz-muenchen.de.
authors.forename: Rainer U
authors.initials: RU
authors.lastname: Meckenstock
mesh_terms: D000085:Acetates / Q000378:metabolism; D000222:Adaptation, Physiological; D001426:Bacterial Proteins / Q000032:analysis; D001565:Benzoates / Q000378:metabolism; D002853:Chromatography, Liquid; D003470:Culture Media / Q000737:chemistry*; D005290:Ferric Compounds / Q000378:metabolism; D045302:Geobacter / Q000254:growth & development* / Q000378:metabolism*; D020543:Proteome / Q000032:analysis; D013312:Stress, Physiological; D053719:Tandem Mass Spectrometry
chemical_list: D000085:Acetates; D001426:Bacterial Proteins; D001565:Benzoates; D003470:Culture Media; D005290:Ferric Compounds; D020543:Proteome; C025314:ferric citrate
keywords: Geobacter metallireducens; In situ physiology; Label-free proteomics; Retentostats