BALI - Biorefinery concept for algal biomass

Compared to agriculture, mariculture is still in its infancy.

In BALI, regionally cultivable biomass is obtained from macroalgae and selected microalgae, and ingredients for new applications are developed.

BALI is developing biorefinery concepts for the use of regional algae biomass, which could partially replace land-intensive, traditional agriculture. The project partners are utilizing the cascade of algae biomass by extracting useful marine sugars and bioactive secondary metabolites in addition to the classic fatty acids. The combined extraction and biotechnological use of various algae ingredients improves the value chains of marine, renewable resources.

We are pursuing the following product goals:

• Natural, cosmetic skin lighteners based on secondary metabolites of marine algae,

• Tailor-made marine algae sugar compounds for the cosmetic and pharmaceutical industries and as fine chemicals, and

• Polysaccharide-utilizing enzymes as new biocatalysts.

From June to August 2021, an experiment with bladderwrack cultures was conducted at five stations along the Schlei (Schleswig, Stexwig, Missunde, Gut Bienebek, and Maasholm) as part of the BALI project. Two main questions were answered: 1.) Can bladderwrack be cultivated in the Schlei at all? and 2.) What influence does the increasing salinity along the stations have on the culture in terms of growth by other species?

Click here for the results, published by the Schlei Information Center:

Bladderwrack from the Flensburg Fjord, which was used for the experiment

This is what the experimental cultures looked like (here: station near the “Odin” restaurant in Schleswig)

Can valuable substances for cosmetics, medicine and chemistry be obtained from native marine algae, completely without oil or palm fat? This is exactly what the BALI project investigated. It shows how a sustainable algae-based biorefinery can work.

At the center: brown algae and microalgae from the North Sea and Baltic Sea, which have so far hardly been used, but are rich in useful sugars, bioactive compounds and fats. The project team developed an innovative process for cascade utilization: Several active substances are obtained from the same biomass in order to make the best possible use of the entire alga.

Algae instead of arable land: Why this is important

Compared to classical agriculture, algae have many advantages: They require no fertilizers or freshwater, bind CO₂ and grow quickly, often even on areas that otherwise cannot be used. In BALI, new methods were therefore developed to prepare regional algae biomasses specifically for industrial use.

The aim was to develop three product groups:

• Natural skin lighteners for cosmetics, e.g. from polyphenols

• Tailor-made sugar compounds for medicine and chemistry

• Biocatalysts, meaning enzymes that make industrial processes more sustainable

From the sea into the laboratory: What was achieved?

An important focus was on the development of so-called enzyme toolboxes, with which certain sugar molecules can be specifically extracted from algae, including laminarin, fucoidan, mannan or inulin. The researchers tested over 30 different enzymes and developed processes that are even scalable in industry.

In the subproject of IMaB (Institute for Marine Biotechnology), extractable polysaccharides from microalgae such as Thalassiosira weissflogii were also isolated. It became clear that the composition of the sugars changes depending on the culture conditions, an important lever for targeted active substance production.

The bioactive effect of fucoidans, special sugars from brown algae, was also tested. First results indicate that they inhibit the growth of harmful bacteria and potentially have skin-protecting properties.

Field test in the Schlei: Algae culture under real conditions

In addition to laboratory technology, the project also went into the field: In the Schlei, it was tested whether the native bladderwrack (Fucus vesiculosus) can be successfully cultivated. The result: yes, but the quality of the harvested biomass varies greatly depending on location and salinity. Especially in the area with higher salinity, the wrack showed better growth, but the infestation with fouling organisms, e.g. barnacles and bryozoans, was also stronger here.

The study in the Schlei showed: Macroalgae production is possible at the site, but the harvested biomass is more suitable for technical applications, e.g. as fertilizer. The method can also help bind nutrients from the water and relieve coastal ecosystems.

Project coordination: Prof. Dr. Thomas Schweder, University of Greifswald