Difference between revisions of "Part:BBa K2565001"

Revision as of 01:09, 18 October 2018

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).

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

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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.

Usage and Biology

Sequence and Features