title: Selective methanol or formate production during continuous CO₂ fermentation by the acetogen biocatalysts engineered via integration of synthetic pathways using Tn7-tool.
abstract: Methanol-resistant mutant acetogen Clostridium sp. MT1424 originally producing only 365 mM acetate from CO₂/CO was engineered to eliminate acetate production and spore formation using Cre-lox66/lox71-system to power subsequent methanol production via expressing synthetic methanol dehydrogenase, formaldehyde dehydrogenase and formate dehydrogenase, three copies of each, assembled in cluster and integrated to chromosome using Tn7-based approach. Production of 2.2 M methanol was steady (p < 0.005) in single step fermentations of 20 % CO₂ + 80 % H₂ blend (v/v) 25 day runs each in five independent repeats. If the integrated cluster comprised only three copies of formate dehydrogenase the respective recombinants produced 95 mM formate (p < 0.005) under the same conditions. For commercialization, the suggested source of inorganic carbon would be CO₂ waste of IGCC power plant. Hydrogen may be produced in situ via powered by solar panels electrolysis.
authors.affiliation: Syngas Biofuels Energy, Inc., P.O. Box 300819, Houston, TX 77230, USA. michael@syngasbiofuelsenergy.com
authors.forename: Michael
authors.initials: M
authors.lastname: Tyurin
authors.forename: Michael
authors.initials: M
authors.lastname: Kiriukhin
mesh_terms: D000429:Alcohol Oxidoreductases / Q000138:chemical synthesis / Q000378:metabolism; D000445:Aldehyde Oxidoreductases / Q000138:chemical synthesis / Q000378:metabolism; D053898:Biosynthetic Pathways / Q000235:genetics; D002245:Carbon Dioxide / Q000378:metabolism; D003013:Clostridium / Q000235:genetics* / Q000378:metabolism*; D004251:DNA Transposable Elements; D004269:DNA, Bacterial; D005285:Fermentation / Q000502:physiology; D005560:Formate Dehydrogenases / Q000138:chemical synthesis / Q000378:metabolism; D005561:Formates / Q000378:metabolism*; D006859:Hydrogen / Q000378:metabolism; D007218:Industrial Microbiology; D000432:Methanol / Q000378:metabolism*; D014169:Transformation, Bacterial
chemical_list: D004251:DNA Transposable Elements; D004269:DNA, Bacterial; D005561:Formates; D002245:Carbon Dioxide; D006859:Hydrogen; D000429:Alcohol Oxidoreductases; C019641:alcohol dehydrogenase (acceptor); D005560:Formate Dehydrogenases; D000445:Aldehyde Oxidoreductases; C087006:formaldehyde dehydrogenase, glutathione-independent; D000432:Methanol