Part:BBa_K2533050

mleS-lldp-ldhA

malate dehydrogenase & L-lactate permease & D-lactate dehydrogenase

Usage and biology

It encodes malate dehydrogenase, L-lactate permease and D-lactate dehydrogenase, which could produce and transport more lactate. mleS could convert malic acid to L-lactate, lldP could transport lactate out of the cell. ldhA could convert pyruvate to D-lactate. In this way, Rhodopseudomonas palustris could efficiently transport produced lactate out of the cell, which later will be used by Shewanella.

Characterization

This is one section for lactate production and transportation part.

Figure1:mleS-lldP-ldhA

DNA Gel Electrophoretic

To make sure that we get the target gene, we did DNA gel electrophoretic for verification. And here is the result.

Figure2:Verification of successful transformation of pSB1C3-mleS-lldP-ldhA

Our target genes are 4339bp, and as the marker is DS5000, we could be sure that the bright bands in this picture are our target genes.

Electrogenesis

By detecting the production of lactate after expressing, we might find out whether RBS-mleS-RBS-lldP-RBS-ldhA could effectively help Rhodopseudomonas palustris transport produced lactate out of the cell.

Figure3:shows that our modification is effective. Every gene circuits can help strains produce lactate, and mleS-lldP-ldhA is the most efficient one. Therefore, our construction of gene circuits achieve the goal to help strains produce lactate.

It could be demonstrated that targeted genes could be expressed in the engineered cells. More lactate has been produced and transported by engineered bacteria.