We utilise The Biosurfactor biobrick (BBa_K653000) designed by Panama 2011 that encodes rhlA and rhlB, two enzymes for rhamnolipid production. We put the biobrick under T7lac promoter with strong RBS (BBa_K613010), and double terminator BBa_B0015.

We designed our Rhamncolipid to express reporter protein when producing rhamnolipid. We tried to find best reporter for our system that has fast turnover and doesn’t have significant fitness cost to the bacteria. We tested two reporters, RFP and aeBlue, with each reporter hasdifferent tags, either not tagged, LAA-tagged, or LVA-tagged. The LAA and LVA tags have the shortest half-life in 37oC (our cultivation temperature) in RFP and GFP, respectively.

We also designed our control device which encodes LacI under different promoter strength, strong, medium, or even without the control.

Reporter Selection

We transformed E. coli BL21(DE3) with different reporter proteins (RFP and aeBlue) with different tags (none, LAA, LVA). We induced the transformants using IPTG and observe the OD600 for bacteria growth and measure each reporter.

The results showed that [to be continued]. Therefore, we selected [to be continued] as our reporter device.

Rhamnolipid production

We transformed E. coli BL21(DE3) with The Biosurfactor and reporter. We also include control system with different strength in expressing lacI. We grew our transformants in autoinduction media (as described by [to be continued]) and check OD600, rhamnolipid production. The result showed that expressing LacI under [to be continued] gave the highest OD600 and rhamnolipid concentration.

Rhamnolipid test

We tested our produced rhamnolipid for its characteristics and surfactant activites.

The results showed that [to be continued]