Academics at the University of Edinburgh are helping Unilever achieve their sustainability goals with a yeast-based surfactant alternative.

Unilever has committed to halve the environmental footprint of making their products as part of their Sustainable Living Plan. A key ingredient in many of Unilever’s products are surfactants, molecules which have both water-loving and oil-loving regions and act as a type of soap, enhancing cleaning. Saponins are natural surfactants found in plants, but they are present at low levels and the process of extracting them is not commercially feasible, so the company wanted to find a more sustainable solution which could lead to a commercial supply of saponin surfactants .  Through this IBioIC-funded project, Susan Rosser’s group at the University of Edinburgh have been developing a sustainable way to produce saponins in yeast.

Why saponins?
Saponins are naturally occurring molecules found in many plant species. The molecules serve to protect the plants from attack by microbes and some animals due to their taste and toxicity. The soap-like properties of saponins are of interest as a replacement for non-biobased surfactants, but extraction of saponins from plants is not commercially viable at the required scale.

The challenges of saponin production in yeast
Engineered yeast have the potential to be a more sustainable saponin factory than other saponin producers, however, the main challenge to be overcome as part of the project was to eliminate the negative impact of the saponin product on growth of the yeast itself. The strategy was two-fold. Firstly, as saponins act like soaps, there was a significant challenge associated with producing them at high concentrations in yeast without compromising the yeast cells. The second challenge was to identify the components of saponins that are toxic, so that these could be removed from the repertoire of saponins produced.

Successful production routes identified
Unilever were pleased that the Rosser group was able to engineer yeast to produce saponins and to identify ways to reduce the toxic effects of the molecules on the cells. The team are continuing to work together through an IBioIC funded PhD in a relationship that looks set to continue for some time.

To hear more about project funding, contact projects@ibioic.com