Production of rhamnolipids of variable compositions by different bacterial strains aiming to characterize them as biosurfactants for different applications

Abstract

The demand for more environmentally friendly products has grown in recent years. An example of this movement is the construction of a factory for the production of rhamnolipids by the company Evonik in Slovakia with investments exceeding 100 million euros. Rhamnolipids are biosurfactants composed of 3-hydroxyalkanoates and rhamnose that can have a widely varied composition. They were originally detected as a product of Pseudomonas aeruginosa, but later in other Pseudomonas species and also Burkholderia. Recombinant lines producing rhamnolipids have been designed since 1995. The Bioproducts Laboratory began studies on rhamnolipid production around 20 years ago. The P. aeruginosa LFM634 strain was selected as a good producer of rhamnolipids from carbohydrates. Different LFM634 mutants were obtained to increase biosurfactant production or to allow diversification of its composition. Recombinant rhamnolipid-producing P. putida or Escherichia coli strains have also been constructed. Basic conditions were also evaluated for establishing cultures at higher cell densities to increase productivity in rhamnolipid production processes. In this project, we intend to apply fed-batch cultivation for the production of rhamnolipids of different compositions. These will be purified and their composition analyzed using different techniques. In this way, it will be possible to make materials of different compositions available for their characterization as surfactants in different applications.