Larvicidal activity of rhamnolipids produced by Pseudomonas aeruginosa LBI 2A1 against Aedes aegypti larvae.

Dengue is a tropical disease caused by a virus, the most important vector of this is the mosquito Aedes aegypti, this disease affect about 100 millions of people per year and causes around 30,000 deaths. Currently there is still no effective vaccine for the virus, so the best way is to control the vector population using insecticides. However insecticides can cause environmental damage. Recent studies have reported insecticidal activity of rhamnolipids produced by Pseudomonas aerugionosa, this biosurfactant show low toxicity and are capable of reducing the interfacial and superficial tension. The appeal for the use of more environmentally friendly insecticides conducted to evaluate the insecticidal potential of rhamnolipids against Aedes aegypti larvae. To this rhamnolipids were produced in the bioreactor using mineral medium free of calcium and sunflower oil as a carbon source. The microbial strain used was Pseudomonas aeruginosa LBI 2A1.  After purification, the rhamnolipids solutions were prepared with the following concentrations 50, 100, 200, 300, 400, 600, 800, 900 and 1000mg / L, then ten larvae were transferred to flasks with 40 ml of biosurfactant solution. All larvae were killed after 18h of exposure to the concentrations of 1000, 900 and 800mg/L. At concentrations of 600 and 400mg/L the larvae were dead after 48 hours. The other concentrations reduced the larval population to less than 50%. This demonstrates the insecticidal activity of rhamnolipids against Aedes aegypti.