Part:BBa_K2533030

RBS-dld

It encodes D-lactate dehydrogenase.

Usage and biology

dld refers to FAD-dependent D-lactate dehydrogenase which could catalyze D-lactate’s transformation into pyruvate. With the overexpression of dld, Shewanella could utilize D-lactate more efficiently, which brings more electricity to be produced.

Characterization

This is one section for lactate utilization part.

Figure1. RBS-dld

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-dld

Our target gene is 3366bp, 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 dld could be overexpressed by engineered Shewanella, we did Real-Time Quantitative PCR.

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

As we can see from this figure, dld could be overexpressed by engineered Shewanella. For further verification, we used the engineered bacteria to produce electricity.

Electrogenesis

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

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

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