The bioconversion of ethanol to biosurfactants and dye by a novel coproduction technique

Rhamnolipids, multifunctional glycolipid biosurfactants, and pyocyanine, a phenazine dye, were coproduced by Pseudomonas BOP100 from ethanol as the sole carbon source. Bacterial growth was dependent on the ethanol concentration in the medium. Pyocyanine was produced only during the exponential phase, while rhamnolipids production continued during the stationary phase, indicating two different ways of production for each of the products. Maximum coproduction capacity was observed at a concentration of 3% ethanol; yield of rhamnolipids was 3 g/L, and of pyocyanine 0.2 g/L. The products were characterized to confirm their chemical structures.