Macroalgae, or seaweed, is one of the largest un-exploited global biomass resources for a sustainable production of food and replacement of fossil resources. Open-sea-based cultivation of macroalgae in Europe has huge potential. However, large-scale cultivation will not be a...
Macroalgae, or seaweed, is one of the largest un-exploited global biomass resources for a sustainable production of food and replacement of fossil resources. Open-sea-based cultivation of macroalgae in Europe has huge potential. However, large-scale cultivation will not be a reality unless we increase added value throughout the value chain with an integrated biorefinery concept. Macro Cascade has worked towards this vision by demonstrating large-scale cultivation and harvest and developing a biorefinery technology platform to convert macroalgae to a variety of value-added products for different industry sectors. The project offers economic, environmental and social benefits using seaweed as raw material, with the aim to expand the employment in the maritime sector. Shipbuilders will have the opportunity to expand their markets by building innovative harvesting ships. Storage and conversion will provide high quality jobs at the plants. Biorefinery of the produced seaweed will create a portfolio of new ingredients for food, feed, cosmetics, and bioplastics. Furthermore, by minimizing the pressure on land resources, society as a whole will benefit from this project.
Macro Cascade has been in active progress during the past 36 months.
In WP1, 1D and 2D substrates have been tested. 5 cultivation rigs have been developed and tested for feasibility to seaweed species and site characteristics. Yields of 56 kg ww/m2/year (vertical rope growth and two annual harvests) have been reached at the offshore cultivation site in the Faroe Islands. Data for the seasonal and regional variation of biochemical compounds in S. latissima is collected in the Faroe Islands over 2-3 years period and showed a seasonal variation for dry matter, ash, nitrogen, iodine, and glucose. No variation between two cultivation sites (an exposed and a sheltered) and no variation with depths below surface (0-10m). The results are very useful for planning of a biorefinery platform, end-products, and harvesting. Lab seeding of Palmaria palmata showed good results and dense seeding on nets in the field was observed. Prototype of mechanical harvesting machine was tested and only little adjustment is needed for it to be commercial useful.
In WP2, different conditioning technologies e.g. screw-pressing, drying, and ensiling have been investigated with protocols established. Long term storage by ensiling showed promising and different conditions should be chosen depending on the targeted bioactive compounds in the following biorefinery process.
In WP3, Systematic assessments of novel microbes showing probiotic potential, discovery and characterization of new enzymes acting on macroalgae were carried out. Feed and food grade products using controlled lactic acid bacterial fermentation of seaweed and canola have been developed. Food grade product showed good anti-inflammatory activity in human cells. The clinical tests are running and will be finished in the final year. Feed grade product was tested in weaned piglets for a period of 9 weeks at two inclusion levels (2.5 % and 5 %, dry feed basis). A systemic improvement in the piglets was observed, from a positive gut microbial modulation to improvement in gut development and reduction in inflammation.
In WP4, the biorefinery schemes for the production of multiple products from brown seaweed have been developed. The recovery efficiency and properties of extracted mannitol, laminarin, alginate, fucoidan, and proteins were evaluated. Due to the biomass composition, alginate is determined as main product from S. latissima and one phlorotannin present in S. latissima was identified.
In WP5, several enzymes have been produced and procedures have been designed and are being tested for refining the algal polysaccharides (laminarin, fucoidan, alginate) with potential uses of the products in food, feed, cosmetic and chemical industries. Some promising processes are optimized and scaled up, including the processes for producing branched beta glucan oligosaccharides from laminarin, and enzymatic processes for producing valuable building blocks from alginate. A full patent has been obtained for the former in selected European countries and a PCT patent has been filed for the latter. Chemical processes have also been developed for generation of chemicals of industrial interest from the enzymatically produced alginate intermediates. Highly novel fucoidanases have been discovered and developed, which can be used for generating innovative bioactive derivatives of fucoidan.
In WP6, the economic prospects for seaweed cultivation, storage and valorisation towards high-value products such as functional feed/food, pre-biotic oligosaccharides and a multiproduct cascading scheme have been explored. Capital cost and operating costs were significant in all steps. The primary cost driver found is the cost of seaweed cultivation. The best economics are for functional food, followed by functional feed.
•A Macro Cascade demonstrated offshore cultivation system is so far proven to be scalable, survivable in open ocean conditions, and the content of seaweed can be predicted. The impact of these achievements has been a concrete technology transfer of the offshore MACR system used in Macro Cascade (including direct seeding techniques) to the East and West coast of the U.S., creating workplaces in coastal communities.
•A comprehensive and unique selective breeding program of different S. latissima strains is running.There has been no prior attempt in Europe to breed, cultivate and process macroalgae for targeted higher value biomolecules according to industrial requirements. Validation of 1 species based on the selective breeding is expected.
•The overall cost is a function of yield compared to total capital and operating cost (CAPEX+OPEX / Yield). The work so far has provided data on actual costs of a production scale of up to 100 tonnes wet weight of cultivated biomass per year. The overall cost has been reduced significantly, but the capital cost and cost of operation are still significant in the economic feasibility study. It will be further lowered due to mechanization, selective breeding and economy of scale.
•Several promising processes of refining algal polysaccharides to the products in food, feed, cosmetic and chemical industries are optimized and scaled up. A full patent has been obtained and a PCT patent has been filed for the latter.
•Feed and food grade products using controlled lactic acid bacterial fermentation of seaweed and canola are developed. Good anti-inflammatory activities in human cells are documented. The optimized food grade product is under testing in rheumatic patients at Silkeborg Hospital in Denmark. Feed grade products were tested in pigs with the aim to out-phase zinc for reducing diarrhea. Promising effects for reducing the use of zinc along with prescription antibiotics while obtaining the same performance in pig production have been observed. Macro Cascade thus has further impact on the animal well-being and reduction of anti-biotics in healthy feed applications, as well as impact on healthy food ingredients with expected prebiotic functionalities which are under testing.
More info: https://www.macrocascade.eu/.