Microalgae: the green gold of biotechnology

The Institute of Life Sciences and the Life Sciences Engineering program, with its biotechnology specialization at HES-SO Valais-Wallis, have been working on microalgae research for several years.

These ancient and ubiquitous organisms were initially cultivated in the laboratory under heterotrophic conditions, meaning they were grown without light as an energy source, instead utilizing organic carbon (notably sugars) to promote biomass growth in standard laboratory reactors. This approach allowed for the application of microbiology expertise and sterile working techniques to microalgae cultivation.

By optimizing the nutrient supply to the algae cells, various biomass-derived compounds have been successfully produced, including pigments, antioxidants, lipids, and proteins. This expertise has led to collaborations with companies in the cosmetics industry (such as La Prairie and Qenax) and the food sector (e.g., Alver SA).

To broaden its scope, the biotechnology research group has also focused on the study of photoautotrophic organisms, which can use light as an energy source and CO₂ as a carbon source. As part of this work, a continuous culture process has been developed to produce phycocyanin, a phycobiliprotein extracted from spirulina.

The use of photobioreactors as a production tool represents a major asset for the laboratory. Furthermore, microalgal photosynthesis aligns perfectly with current environmental challenges, particularly by contributing to the reduction of greenhouse gases. Additionally, recycling of input and output flows from fermentation processes, as well as the combination of microalgae with other microorganisms (such as yeasts), makes them an ideal candidate for environmental biotechnology.

Continuously seeking innovative processes, the research group is currently exploring the production of polyunsaturated fatty acids from marine microalgae, intended for human and animal nutrition.

Thanks to their great diversity and metabolic versatility, microalgae represent a unique resource for the production of bioactive compounds of interest.

Contacts : julien.pott@hevs.ch, manfred.zinn@hevs.ch, véronique.amstutz@hevs.ch