title: Expression of amplified synthetic ethanol pathway integrated using Tn7-tool and powered at the expense of eliminated pta, ack, spo0A and spo0J during continuous syngas or CO2 /H2 blend fermentation.
abstract: OBJECTIVE
  To engineer acetogen biocatalyst selectively overproducing ethanol from synthesis gas or CO2 /H2 as the only liquid carbonaceous product.
  
  
  RESULTS
  Ethanol-resistant mutant originally capable of producing only acetate from CO2 /CO was engineered to eliminate acetate production and spore formation using our proprietary Cre-lox66/lox71-system. Bi-functional aldehyde/alcohol dehydrogenase was inserted into the chromosome of the engineered mutant using Tn7-based approach. Recombinants with three or six copies of the inserted gene produced 525 mmol l(-1) and 1018 mmol l(-1) of ethanol, respectively, in five independent single-step fermentation runs 25 days each (P < 0.005) in five independent repeats using syngas blend 60% CO and 40% H2 . Ethanol production was 64% if only CO2 + H2 blend was used compared with syngas blend (P < 0.005).
  
  
  CONCLUSIONS
  Elimination of genes unnecessary for syngas fermentation can boost artificial integrated pathway performance.
  
  
  CONCLUSIONS
  Cell energy released via elimination of phosphotransacetylase, acetate kinase and early-stage sporulation genes boosted ethanol production. Deletion of sporulation genes added theft-proof feature to the engineered biocatalyst. Production of ethanol from CO2 /H2 blend might be utilized as a tool to mitigate global warming proportional to CO2 fermentation scale.
authors.affiliation: Ajinomoto-Genetika Research Institute, Moscow, Russia.
authors.forename: M
authors.initials: M
authors.lastname: Kiriukhin
authors.forename: M
authors.initials: M
authors.lastname: Tyurin
mesh_terms: D000084:Acetate Kinase / Q000235:genetics; D000085:Acetates / Q000378:metabolism; D000426:Alcohol Dehydrogenase / Q000235:genetics / Q000378:metabolism; D002245:Carbon Dioxide / Q000378:metabolism; D003013:Clostridium / Q000235:genetics / Q000378:metabolism*; D004251:DNA Transposable Elements; D004269:DNA, Bacterial / Q000235:genetics; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation; D005740:Gases / Q000378:metabolism; D017353:Gene Deletion; D005818:Genetic Engineering; D005822:Genetic Vectors; D006859:Hydrogen / Q000378:metabolism; D007218:Industrial Microbiology; D010709:Phosphate Acetyltransferase / Q000235:genetics; D013171:Spores, Bacterial
chemical_list: D000085:Acetates; D004251:DNA Transposable Elements; D004269:DNA, Bacterial; D005740:Gases; D002245:Carbon Dioxide; D000431:Ethanol; D006859:Hydrogen; D000426:Alcohol Dehydrogenase; D010709:Phosphate Acetyltransferase; D000084:Acetate Kinase