Part:BBa_K2565001

Shewanella ldhA gene highly expressed in E. coli

This composite part is used to constitutively express high levels of Shewanella oneidensis MR-1 fermentative lactate dehydrogenase NADH dependent ldhA (BBa_K2565000) in E. coli, locus tag SO_0968.

In MFCs the microorganisms transfer electrons to reduce metals and if a conducting wire is connected to the metal cathode, current will run through the wire and the electricity can be utilized. The goal was to create energy on demand by engineering E. coli to produce a carbon source for an electrogenic bacteria. Shewanella oneidensis (Shewanella species isolated from Lake Oneida, New York) is a laboratory model strain of electrogenic bacteria and he complete genome of Shewanella is available. The preferred carbon source of Shewanella is lactate (Brutinel and Grainick, 2012) and the enzyme that is involved in lactate synthesis in Shewanella is the ldha gene (Le Laz et al. 2016).

This figure shows that the media with E. coli constitutively expressing ldhA contains more lactate than LB only.

This figure shows the amount of lactate in the media of cultures so that when Shewanella and E. coli are grown together there is more lactate in the media. The MG1655 strain of E. coli does not express the Shewanella ldhA gene.

This graph shows the voltage produced by microbial fuel cells (MFC) in 15 hours. The MFC with Shewanella and E. coli produced more voltage than Shewanella alone. The MFC with Shewanella and E. coli expressing Shewanella ldhA produced more consistent voltage than E. coli without Shewanella ldhA.

References

Brutinel ED, Gralnick JA. Preferential utilization of D-lactate by Shewanella oneidensis. 2012.Appl Environ Microbiol. 2012 Dec;78(23):8474-6. doi: 10.1128/AEM.02183-12.

Le Laz S, Kpebe A, Bauzan M, Lignon S, Rousset M, Brugna M. 2016. Expression of terminal oxidases under nutrient-starved conditions in Shewanella oneidensis: detection of the A-type cytochrome c oxidase.Sci Rep. 2016 Jan 27;6:19726. doi: 10.1038/srep19726.

Usage and Biology

Sequence and Features

Assembly Compatibility:

• 10
  COMPATIBLE WITH RFC[10]
• 12
  INCOMPATIBLE WITH RFC[12]

  Illegal NheI site found at 7
  Illegal NheI site found at 30
  
• 21
  COMPATIBLE WITH RFC[21]
• 23
  COMPATIBLE WITH RFC[23]
• 25
  COMPATIBLE WITH RFC[25]
• 1000
  COMPATIBLE WITH RFC[1000]