Jan Kuperus


Biorefinery of microalgae aiming on protein extraction

Algal biorefinery is aiming on efficient fractionation of the different microalgae cell components. Literature suggests that biorefinery of microalgal biomass results in an economically feasible production system of the major microalgal components, e.g. lipids, proteins and carbohydrates (Wijffels, et al. 2010). These components can be used for bio-based commodities, as well as for high value compounds.

For microalgal proteins, Schwenzfeier et al. (2011) was able to separate a water soluble protein fraction that showed promising techno-functional properties for application in the food industry. At this moment, it is not clear whether similar properties can be found for the remaining non-water soluble protein fraction. This fraction contains a large proportion of entrapped white and water-soluble Rubisco.


The aim of the project is to establish a mild fractionation process to increase the yield of Rubisco protein and secure it’s functionality during the entire process.


This project studies different aspects of the entire process of mild extraction of Rubisco protein from microalgae. Schwenzfeier et al. (2011), extracted 21% of the total protein present in Tetraselmis sp.. The majority of these proteins is either associated to the cell wall or entrapped in cell organelles. One of the entrapped proteins is Rubisco. It is mainly found in the pyrenoid structures of the microalgae (Kuchitsu, Tsuzuki et al. 1988)This project starts with the investigation how the pyrenoid structures are affected by specific growth conditions and how the protein content (e.g. of Rubisco) changes with the growth conditions. Secondly, different mild cell disruption methods will be used to open the microalgae cells and separate the pyrenoid structures from the water soluble fraction. Thirdly, mild methods will be applied to extract the proteins from the pyrenoid structures. The different protein fractions will be characterized for functional food and feed properties.

Thesis opportunities

Various BSc or MSc thesis opportunities are available within this project. Please feel free to visit me (Biotechnion, room nr. 617) or send me an email! jan.kuperus@wur.nl


This project is financed by STW, protein innovation program.