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Organisation of work

OrganisationThe research in Sweaweed is organised into five work packages, WPs. Click to read short descriptions of the work in each WP:

WP 1. Cultivation and breeding

WP 2. Disintegration

WP 3. High value food ingredients

WP 4. Fine chemicals

WP 5. Bio-based materials

 

WP 1. Cultivation and breeding

In WP1 we develop methods for producing seaweed biomass, the base for further research in WPs 2-5.

We optimize techniques for seeding, growth of juveniles and open water cultivation for Swedish conditions. A key challenge is to develop new culture varieties through selective breeding, and to map the metabolic profile in the new varieties. Another important task is to establish techniques for artificial induction of spore/gamete production. This will allow for an extended harvest season and the exploitation of seasonal variations in the high-value compounds.

Using local populations
We focus on two seaweed species; the green alga Ulva lactuca and the red alga Porphyra umbilicalis. Breeding individuals will be chosen from local populations that are adapted to the specific environmental conditions in Sweden. This will also avoid introducing alien populations to Swedish waters.

Contact: Gunilla Toth, & Henrik Pavia, University of Gothenburg.

WP 2. Disintegration of biomass

In WP 2 we develop new techniques for disintegrating the seaweed biomass, to enable the extraction of high-value compounds in WPs 3-5.

Seaweed have a highly integrated cellular structure. In order to successfully extract the high-value compounds, this structure must be opened up. Besides this, biomass particle size and sometimes also water content, must be reduced. We aim to develop new smart techniques for the purpose, based on “green” energy-saving principles.

Physical and enzymatic methods
We will test a new air milling technique for biomass disintegration, which also partly dry the raw material. We also aim to substantially extend existing techniques for enzymatic degradation. From the selected seaweeds, we will isolate marine bacteria that produce seaweed-degrading enzymes. Extracellular enzymes will be identified, purified and characterized for properties. Enzymes needed for work in WPs 3-5 will be produced in suitable quantities by using microbial hosts.

Contact: Eva Albers & Ingrid Undeland, Chalmers.

WP 3. High value food ingredients

In WP3 we evaluate methods for extracting seaweed-based food ingredients and additives – fatty acids, proteins, antioxidants and colorants.

Extracting lipophilic compounds such as fatty acids and antioxidants traditionally involves the use of toxic organic solvents. We will evaluate environmentally friendly alternatives such as ethanol and supercritical fluid extraction. For the extraction of proteins we will use water-based techniques with and without enzyme pre-treatments and reducing agents. The two latter will help to overcome the strong covalent bonds that attach proteins to for example carbohydrates in the cell walls. Breaking such bonds also appears to be necessary to maximize the digestibility of seaweed proteins.

Avoiding the seaweed flavour
The specific seaweed flavour could be an obstacle for the introduction of seaweed based food products in non-Asian countries. The flavour arises e.g. from lipid oxidation-derived aldehydes and acids. We will investigate the degree of lipid oxidation taking place during storage of seaweed biomass. Handling procedures which can preserve the seaweed´s own pool of antioxidants will also be evaluated.

Contact: Ingrid Undeland, Chalmers.

WP 4. Fine chemicals

In WP 4 we evaluate methods for extracting seaweed compounds that could be useful as fine chemicals in different industrial applications.

Seaweed biomass contains molecules that are different from terrestrial material. Thus, they can provide new interesting compounds as fine chemicals in technical and medical applications. This includes for example starting molecules for chemical synthesis, stabilizers for lipid-based products as biodiesel, and anticoagulant or antithrombotic agents.

Evaluating enzyme action
Extracting molecules for fine chemicals often include the use of organic solvents. Using enzymes for assisting lipophilic extraction would be more environmental friendly and non-destructive. Water soluble enzymes can aid the retrieval of compounds through selective release of specific molecules, while retaining other components intact. We will evaluate the use of enzymes isolated from bacteria in WP 2, and assess the extracted fractions to identify candidates for future applications.

Contact: Eva Albers, Chalmers.

WP 5. Bio-based materials

In WP5 we develop techniques for isolating seaweed macromolecules and convert them into functional biomaterials.

Among the macromolecular components we expect to be find in Porphyra umbilicalis and Ulva lactuca are pectins, ulvan, cellulose and carrageenan. These are all polysaccharides with the potential to be used as renewable alternatives to conventional fossil-based polymers. The exact composition of the polysaccharides from green and red algae is not fully known. We plan to map the structures, and study how they vary with isolation conditions and with respect to seasonal changes.

Avoiding modifications
A key challenge is to develop efficient, yet mild, techniques to successfully isolate valuable components – without causing unwanted modifications or degradation of other co-components present in the algae. We will use in-house strategies to derive thermoplastics and gels from carrageenan and cellulose. The bioactive properties of carrageenan are not fully explored, but antioxidative qualities are anticipated. Among targeted applications are e.g. cosmetics formulations.

Contact: Ulrica Edlund, KTH.
 

Page Manager: Susanne Liljenström|Last update: 9/23/2016
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