Samenvatting

This thesis project has been carried out at VHL (Van Hall Larenstein University of Applied Sciences) and consists of three different parts; the first part is an experiment in which during 20 days of cultivation the optimum nitrate concentration for protein production in Ulva lactuca is sought. U. lactuca was exposed to four different concentrations of nitrate to find an optimum for growth and protein production for 20 days. The different nitrate concentrations were: 0 μmol/L–1, 50 μmol/L–1, 100 μmol/L–1 to 200 μmol/L–1 that was delivered to the U. lactuca in artificial seawater with a salinity of 30 parts per thousand. During the cultivation the temperature has been kept at 15°C. After the cultivation experiment, research has been conducted on the influence of different protein concentrations in the start material on the extraction of protein in both pellet and supernatant. Extractions were conducted in triplicate for both extraction methods, the first extraction method was at room temperature with demineralized water and the second extraction method was one with increased pH and a temperature of 50°C. In this research it has been concluded that protein concentrations in the start material did not significantly influence the extractable amount of protein. The final part of the thesis project is a literature study on the effect of protein extracted from U. lactuca on people, planet and profit in the aquaculture sector based on literature. The main points gathered from this study were that U. lactuca protein has small impacts as protein alternative in the aquaculture sector in a triple P perspective (people, planet, profit) depending on what cultivation methods are used. Furthermore it became clear that the European market for seaweed has to grow in order for protein from U. lactuca to become an alternative protein source in the aquaculture sector. Summarized, the results found provide us with the conclusion that it is not feasible yet for protein extracted from U. lactuca to be integrated in the aquaculture sector as an alternative protein source. With more time, research and improvement of production systems, the production of seaweed protein as an alternative source of protein will become a possibility in the future.