Seaweeds for biorefinery on the Swedish west coast

Conference poster, 2017

In a sustainable future, the reliance on oil for the production of fuels, chemicals and commodities has to change to renewable resources. However, replacing the 97 million barrels used each day is no easy feat and multiple biorefinery concepts based on a variety of biomasses should be part of the solution. One limitation for terrestrial biomasses, such as forestry and various crops for which these concepts are already in place, is land use. Seaweed does not require land to be grown and could provide a substantial portion of the future biomass needs.

For seaweeds there are other limitations, but to a large extent these relate to them not being domesticized and studied to the same extent as crops or terrestrial plants. Which means they could possibly be overcome. There are industrial processes for alginate and carrageenan already, but the variety of seaweeds gives possibility of new innovation in areas such as materials, food components and bioenergy. To be able to evaluate the potential and identify targets for cultivation as well as breeding the basic composition of a variety of seaweeds has to be known. Studies have shown great intra-species variation in composition depending on abiotic and biotic factors. Hence, suitable targets for future production of seaweed biomass could differ from place to place and not only by natural occurrence.

In this study, 22 seaweed species were collected from and around the national park of Kosterhavet in Sweden to elucidate their basic biochemical composition. Analyses included major constituents (total carbohydrates, total protein, ash and water content) and elemental composition (C, H, N, S, P and 17 heavy metals/micronutrients). From these analyses the picture becomes clear that the main problems with seaweed biomass for biorefinary is the ash (118-419 g(kg dry weight)-1) and its water content (633-875 g(kg wet weight)-1). However, the sugar content (267- 646 g(kg dry weight)-1) makes the biomass very interesting for utilization in a biotechnological process based on a sugar platform as well as materials. With this study, we hope to have lain the ground for future innovation and potential marine industries on the Swedish west coast.