title: Metabolic engineering of Corynebacterium glutamicum for methanol metabolism.
abstract: Methanol is already an important carbon feedstock in the chemical industry, but it has found only limited application in biotechnological production processes. This can be mostly attributed to the inability of most microbial platform organisms to utilize methanol as a carbon and energy source. With the aim to turn methanol into a suitable feedstock for microbial production processes, we engineered the industrially important but nonmethylotrophic bacterium Corynebacterium glutamicum toward the utilization of methanol as an auxiliary carbon source in a sugar-based medium. Initial oxidation of methanol to formaldehyde was achieved by heterologous expression of a methanol dehydrogenase from Bacillus methanolicus, whereas assimilation of formaldehyde was realized by implementing the two key enzymes of the ribulose monophosphate pathway of Bacillus subtilis: 3-hexulose-6-phosphate synthase and 6-phospho-3-hexuloisomerase. The recombinant C. glutamicum strain showed an average methanol consumption rate of 1.7 ± 0.3 mM/h (mean ± standard deviation) in a glucose-methanol medium, and the culture grew to a higher cell density than in medium without methanol. In addition, [(13)C]methanol-labeling experiments revealed labeling fractions of 3 to 10% in the m + 1 mass isotopomers of various intracellular metabolites. In the background of a C. glutamicum Δald ΔadhE mutant being strongly impaired in its ability to oxidize formaldehyde to CO2, the m + 1 labeling of these intermediates was increased (8 to 25%), pointing toward higher formaldehyde assimilation capabilities of this strain. The engineered C. glutamicum strains represent a promising starting point for the development of sugar-based biotechnological production processes using methanol as an auxiliary substrate.
authors.affiliation: Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich, Jülich, Germany.
authors.forename: Sabrina
authors.initials: S
authors.lastname: Witthoff
authors.affiliation: Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich, Jülich, Germany.
authors.forename: Katja
authors.initials: K
authors.lastname: Schmitz
authors.affiliation: Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich, Jülich, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Niedenführ
authors.affiliation: Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich, Jülich, Germany.
authors.forename: Katharina
authors.initials: K
authors.lastname: Nöh
authors.affiliation: Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich, Jülich, Germany.
authors.forename: Stephan
authors.initials: S
authors.lastname: Noack
authors.affiliation: Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich, Jülich, Germany.
authors.forename: Michael
authors.identifier: http://orcid.org/0000-0002-4701-8254
authors.initials: M
authors.lastname: Bott
authors.affiliation: Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich, Jülich, Germany j.marienhagen@fz-juelich.de.
authors.forename: Jan
authors.identifier: http://orcid.org/0000-0001-5513-3730
authors.initials: J
authors.lastname: Marienhagen
mesh_terms: D000446:Aldehyde-Lyases / Q000235:genetics / Q000378:metabolism; D001407:Bacillus / Q000201:enzymology / Q000235:genetics; D002244:Carbon / Q000378:metabolism; D002245:Carbon Dioxide / Q000378:metabolism; D003001:Cloning, Molecular; D048230:Corynebacterium glutamicum / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism*; D003470:Culture Media / Q000737:chemistry; D005557:Formaldehyde / Q000378:metabolism; D015870:Gene Expression; D005956:Glucose-6-Phosphate Isomerase / Q000235:genetics / Q000378:metabolism; D060847:Metabolic Engineering; D000432:Methanol / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D003470:Culture Media; D011994:Recombinant Proteins; D002245:Carbon Dioxide; D005557:Formaldehyde; D002244:Carbon; D000446:Aldehyde-Lyases; C021355:hexose phosphate synthetase; C453580:3-hexulose-6-phosphate isomerase; D005956:Glucose-6-Phosphate Isomerase; D000432:Methanol