Sweet and Clean

Five years ago, the laboratory’s first attempts to produce biosurfactants by means of fermentation created huge mounds of foam, recalls Dr. Hans Henning Wenk, the head of Research and Development at Evonik Care Solutions. However, the experts in Slovenská Ľupča (Slovakia) now have the process firmly under control, and are using rhamnolipids produced by bacteria to manufacture biosurfactants.

Surfactants are contained in dishwashing detergents, shower gels, and bath additives, where they ensure that dirt doesn’t collect again on dishes or skin. In the European Union, surfactants have to largely break down during wastewater treatment, which is why the consumer goods industry is increasingly using biosurfactants. However, the demand is also growing in regions where sewage treatment plants are rare but people are becoming increasingly environmentally conscious.

The main feature of Evonik’s fermentation process is its scalability. Although many natural bacteria convert fats into rhamnolipids, they only do so in microscopic amounts. At Evonik, this task is performed by Pseudomonas putida, a well-researched “safety strain.” “After we gave it the genetic tools to produce rhamnolipids in large amounts, we continuously optimized it further,” says Wenk.

The process ultimately created a strain of bacteria that produces biosurfactants in industrial amounts. “To achieve this, we got bioengineers together with process experts, chemists, and engineers,” reports Wenk. “We benefited here from our experience with the development of surfactants.” The expertise of a physical chemist proved to be crucial because he was able to explain why a surfactant that had some of its parameters modified suddenly behaved completely differently than before. This knowledge enabled the researchers to get the foam under control so that it now only goes into action in sinks and bathtubs.