title: Co-consumption of methanol and succinate by Methylobacterium extorquens AM1.
abstract: Methylobacterium extorquens AM1 is a facultative methylotrophic Alphaproteobacterium and has been subject to intense study under pure methylotrophic as well as pure heterotrophic growth conditions in the past. Here, we investigated the metabolism of M. extorquens AM1 under mixed substrate conditions, i.e., in the presence of methanol plus succinate. We found that both substrates were co-consumed, and the carbon conversion was two-thirds from succinate and one-third from methanol relative to mol carbon. (13)C-methanol labeling and liquid chromatography mass spectrometry analyses revealed the different fates of the carbon from the two substrates. Methanol was primarily oxidized to CO(2) for energy generation. However, a portion of the methanol entered biosynthetic reactions via reactions specific to the one-carbon carrier tetrahydrofolate. In contrast, succinate was primarily used to provide precursor metabolites for bulk biomass production. This work opens new perspectives on the role of methylotrophy when substrates are simultaneously available, a situation prevailing under environmental conditions.
authors.affiliation: Institute of Microbiology, ETH Zurich, Zurich, Switzerland.
authors.forename: Rémi
authors.initials: R
authors.lastname: Peyraud
authors.forename: Patrick
authors.initials: P
authors.lastname: Kiefer
authors.forename: Philipp
authors.initials: P
authors.lastname: Christen
authors.forename: Jean-Charles
authors.initials: JC
authors.lastname: Portais
authors.forename: Julia A
authors.initials: JA
authors.lastname: Vorholt
mesh_terms: D000255:Adenosine Triphosphate / Q000737:chemistry; D018407:Bacterial Physiological Phenomena; D001426:Bacterial Proteins / Q000378:metabolism; D001671:Biochemistry / Q000379:methods; D002245:Carbon Dioxide / Q000737:chemistry; D002247:Carbon Isotopes / Q000737:chemistry; D002853:Chromatography, Liquid / Q000379:methods; D005943:Gluconeogenesis; D013058:Mass Spectrometry / Q000379:methods; D000432:Methanol / Q000378:metabolism*; D020601:Methylobacterium extorquens / Q000378:metabolism*; D015233:Models, Statistical; D009243:NAD / Q000737:chemistry; D009249:NADP / Q000737:chemistry; D019802:Succinic Acid / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D002247:Carbon Isotopes; D009243:NAD; D002245:Carbon Dioxide; D009249:NADP; D000255:Adenosine Triphosphate; D019802:Succinic Acid; D000432:Methanol