This project is carried out in the group of Industrial Biotechnology.
Researchers: Jenny Veide Vilg, Eva Albers, Joakim Olsson
The SEAFARM project aims at developing a sustainable system for the cultivation and use of brown seaweeds, proposing a renewable resource for a future biobased Swedish society. SEAFARM is a cross-disciplinary project including marine biologists, microbiologists, chemists, food scientists, engineers and economists from 5 Swedish universities - KTH Royal Institute of Technology, Chalmers University of Technology, University of Gothenburg, Linneaus University and Lund University. There are also 13 collaborating partners from industry and authorities from three Swedish coastal regions.
Within SEAFARM, one aim of the project is to develop methods for cultivation and harvest of kelp, Saccharina latissima and Laminaria digitata, on the Swedish west coast. Different approaches for subsequent preservation and storage are being investigated, as well as techniques for extraction of different seaweed components. The aim of this is to develop a method for combined fractionation in an integrated biorefinery. The different fractions are thoroughly characterized and recovered for the production of biochemicals, polymers, and food/feed additives. Both whole seaweed biomass and residues from the biorefinery will be evaluated as substrates for production of biogas and biofertilizers. In parallel, a general multi-process sustainability assessment method will be developed to analyze the overall sustainability of the system.
At the division of Industrial Biotechnology at Chalmers, two of the focus areas in SEAFARM are addressed: Preservation and parts of the Biorefinery; while the extraction and processing of polymers for materials is investigated at the Department of Fiber and Polymer Technology at KTH in Stockholm. The Industrial Biotechnology partners are responsible for the soluble carbohydrates and their conversion into biochemicals. We also work in close collaboration with the Division of Food and Nutrition Science at Chalmers, on extraction of food components such as proteins and fatty acids.
After harvest, the biomass rapidly starts to degrade if left untreated. Since it will need to be stored for as much as a year before refining, there is a need for a cheap, reliable and sustainable preservation method to retain the ingoing compounds. Within SEAFARM we are exploring what preservation methods are suitable for the macroalgae and how successful the different methods are at preserving different constituents of the biomass. The main methods we are looking at are variants of ensiling processes due to its low energy demand and environmental benefits, but comparisons to other methods are also in progress. This study is integral to the overall biorefinery in preserving the material, as well as the subsequent processes that are used and products produced.
Extraction and conversion of soluble carbohydrates
Brown seaweeds are extensively used for industrial extraction of alginates, which are mainly used as food additives. However, the brown seaweeds also contain high concentrations of other carbohydrates; in the kelp genus Laminaria, the storage carbohydrates laminarin and mannitol can together constitute up to 55% of the biomass (dry weight), depending on season. Mannitol is a non-cyclic six-carbon sugar alcohol that is the main product of photosynthesis in brown algae, and laminarin is the main storage polysaccharide, consisting mostly of glucose units. In SEAFARM, we extract these carbohydrates and investigate methods for converting them into ethanol. There are two main tracks; enzymatic hydrolysis of laminarin, for subsequent yeast fermentation of the released glucose, and microbial conversion of mannitol into ethanol. We are working with both bacteria and yeasts that are isolated from marine environments, to find novel tools for the conversion of seaweed carbohydrates into biochemicals, such as ethanol.
Funding: Formas, Region of Västra Götaland, external partners of the project