Proof of Concept
The motto of our project is to create a mosquito repellent that is long-lasting, environmentally-friendly, and safe to human skin. We have chosen rhamnolipids, a biosurfactant naturally produced by Pseudomonas aeruginosa, as the main component of our repellent. To prove and quantify the molecule's repelling ability, we have conducted live mosquito experiments. There are two main types of rhamnolipids: di-rhamnolipid and mono-rhamnolipid. Previous research proved that di-rhamnolipids effectively repel mosquitoes when used at an appropriate concentration. Before we test our BioBrick device, which is our mutant Pseudomonas putida strain that produces mono-rhamnolipids and di-rhamnolipids, we conducted the assay with pure compounds to determine whether mono-rhamnolipids also has the same repelling efficacy as di-rhamnolipids. Water and DEET were used as a negative and positive control, respectively. Our landing assay results showed that while DEET was the strongest mosquito repellent with no landings or fed mosquitos, 1 mg/mL mono and di-rhamnolipid still showed significant repulsion as shown in the graph below.
Given the ability of mono-rhamnolipids and di-rhamnolipids to repel mosquitoes, we hope to conduct the same assay with our BioBrick device, P. putida KT2440 transformed with rhlAB and with rhlC, for future work.