Part:BBa_K2533035

RBS-gapA-RBS-mdh-TT

It encodes glyceraldehyde-3-phosphate dehydrogenase and NAD dependent malate dehydrogenase.

Usage and biology

gapA could transform 3- phosphoglyceraldehyde into 1,3- diphosphoglycerate and mdh could transform malate into pyruvate. With the overexpression of gapA-mdh, Shewanella could produce NADH more efficiently, which brings more electricity to be produced.

Characterization

This is one section contained two genes for NADH production part.

Figure1. RBS-gapA-RBS-mdh

DNA Gel Electrophoretic

To make sure that we get the target gene, we did the DNA gel electrophoretic to separate different gene. And here is the result.

Figure2. Verification of successful transformation of pYYDT-gapA-mdh

Our target gene is 2666bp, and as the marker is DS5000, we could be sure that the bright band in this picture is our target gene.

Real-Time Quantitative PCR

To demonstrate that gapA-mdh could be overexpressed by engineered Shewanella, we did Real-Time Quantitative PCR.

Figure3. Relative expression level of gapA-mdh in engineered Shewanella Oneidensis MR-1.

There was no signal in bacteria which contained pYYDT so we chose pYYDT-gapA-mdh as standard quantity.

Electrogenesis

By comparing the ability of producing electricity, we might find out whether gapA-mdh could effectively help Shewanella to produce more electricity.

Figure4. The comparison of electricity production between Shewanella contained pYYDT and pYYDT-gapA-mdh.

It could be demonstrated that targeted gene could be expressed in the engineered cells. More NADH has been produced by engineered bacteria, which helps to produce more electricty.