Diatoms which belong to the microalgae, produce chrysolaminarin, a soluble β-1,3-1,6-glucan as an energy and carbon storage ingredient. Due to its immunomodulatory properties, the polysaccharide is suitable for application in human or animal nutrition. Plants also react to contact by activating their defense mechanisms. Therefore, the polysaccharide also has a possible application as a plant strengthening agent in agriculture.
In the application area of agricultural production, field trials were carried out by our project partners in 2021, after chrysolaminarin had previously been successfully tested as a plant strengthening agent in the greenhouse. The aim of the trials was to reduce the amount of copper needed as a fungicide in viticulture by using the β-glucan. However, further field trials in the different vegetation periods are needed to obtain reliable results.
In animal nutrition, experiments with our soluble β-glucan have been successfully conducted by project partners. Feeding trials on fish showed that β-glucan extracts, specifically from the diatom Phaeodactylum tricornutum, have a positive effect on the intestinal health of juvenile fish in aquaculture due to their anti-inflammatory and antioxidant effects [1]. In experiments on zebrafish, a cholesterol-lowering effect of β-glucans from microalgae was observed, similar to the effect of β-glucans from yeast already on the market [2]. The results show that β-glucans from algae could possibly also be used as cholesterol-lowering agents in human nutrition. However, further studies are needed for this.
In addition to supporting our project partners in application trials, our work at Fraunhofer IGB focused on improving the production process of β-glucan with microalgae (upstream processing). Thus, scenarios were developed on how the β-glucan process can be implemented on an industrial scale. The extraction of β-glucan from the biomass produced (downstream processing) was also further investigated and optimized. For this purpose, β-glucan was integrated into an already existing biorefinery concept described by Derwenskus et al [3].
We were able to acquire further projects to continue our work on this interesting topic. In addition to further experiments on possible applications, the focus is on the implementation of the β-glucan process, its scale-up and automation. Special attention will be given to sensor technology and biointelligent process control in order to further optimize the yield and energy efficiency of the production process.
[1] Reis, B.; Gonçalves, A. T.; Santos, P.; Sardinha, M.; Conceição, L. E. C.; Serradeiro, R.; Pérez-Sánchez, J.; Calduch-Giner, J.; Schmid-Staiger, U.; Frick, K.; Dias, J.; Costas, B. (2021): Immune status and hepatic antioxidant capacity of gilthead seabream Sparus aurata juveniles fed yeast and microalga derived β-glucans, Marine drugs 19 (12)
[2] Gora, A. H.; Rehman, S.; Kiron, V.; Dias, J.; Fernandes, J. M. O.; Olsvik, P. A.; Siriyappagouder, P.; Vatsos, I.; Schmid-Staiger, U.; Frick, K.; Cardoso, M. (2022): Management of hypercholesterolemia through dietary ß-glucans – Insights from a zebrafish model, Frontiers in Nutrition 8
[3] Derwenskus, F.; Schäfer, B.; Müller, J.; Frick, K.; Gille, A.; Briviba, K.; Schmid-Staiger, U.; Hirth, T. (2020): Coproduction of EPA and fucoxanthin with P. tricornutum – A promising approach for up‐ and downstream processing, Chemie Ingenieur Technik 92 (11)
MiReFung – Microalgae preparations for the reduction of fungicide use in viticulture
November 2021 – October 2023
We would like to thank the Ministry for Rural Areas and Consumer Protection Baden-Württemberg (MLR) for funding the project "MiReFung", promotional reference BWFE120131.
Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB