Microalgae grown with waste from the preserves industry to obtain biofertilisers

29 June 2022

Microalgae grown with waste from the preserves industry to obtain biofertilisers

  • The NEIKER technology centre is working on an investigation to reconvert waste from the preserves industry into biofertilisers by growing microalgae
  • This process makes it possible to recover nutrients present in the brine from cooking tuna
  • This result was achieved within the framework of the European SEA2LAND project, coordinated by NEIKER, which aims to turn tonnes of waste from the fishing industry into biofertilisers
  • The initiative falls within the Basque Government’s commitment to boosting the bioeconomy as an economic model of the future, a strategy aligned with the European Union

Every year the European fishing industry generates around 5.2 million of tonnes of waste from the processing of marine fishing that, for the most part, is not reused. Nevertheless, this waste contains high-value minerals like nitrogen, phosphorous, potassium, iron, copper, and zinc, in addition to vitamins and other compounds that could be recovered and leveraged in agriculture.

In this context, the NEIKER technology centre, member of the Basque Research and Technology Alliance (BRTA), is working on the development of new fertilisers which include microalgae in their composition, produced using waste from different tuna preserves from the Basque Country. Specifically, brine, water with a high salt content used to cook fish, containing nutritional compounds in the form of waste tuna skin, meat and fat. This brine, rich in nutrients and minerals, is being used as a culture medium in the production of microalgae.

This investigation, in collaboration with the AZTI technology centre and several Basque canning plants, has tested a biorremediation process to obtain microalgae with a high added value for factory farming, recycling all the nutrients and minerals present in the brine used to cook the fish.

In particular, this biological treatment consists of using the brine as a culture medium for heterotrophic microalgae, in other words, capable of using organic matter for growth, coming from the tidal wetlands of Pobeña (Bizkaia).


Microalgae rich in nutrients

The process is more straightforward that it may seem at first glance. “During their growth process, these microalgae incorporate part of the organic matter present in these cooking waters. More specifically, it ‘eats’ proteins, oils and other nutrient compounds present in the waste”, explains Sonia Suárez, researcher from NEIKER’s Plant Protection and Production Department.

This process lasts approximately 3-4 days, in which time the microalgae are able to consume up to 90% of the nitrogen from the proteins and aminoacids present in the brine.

Once harvested, the microalgae are used in the formulation of products for agricultural use as biofertilisers or biostimulators. Thus, the nitrogen from fish and taken up by the algae reaches the soil, boosting the yields of agricultural corps.

This investigation opens the door to the reuse of a large amount of minerals present in this organic waste from the fishing industry. “Thus, we contribute to the development of biofertilisers enriched with nutrients and a high added value for the European agro-industry”, notes Suárez. In particular, the use of this type of waste could make it possible to recover around 1.8 million tonnes of nitrogen for agriculture.


Reconversion of waste from fish in biofertilisers

This study was conducted within the framework of the European SEA2LAND project, funded by the European Union’s Horizon 2020 programme, with the objective of turning tonnes of fishing industry waste into biofertilisers. With a budget of 7.7 million euros, this ‘sea to land’ strategy proposes the application of more than 10 technologies in 7 case studies in 6 representative areas of European fishing sector (the North, Baltic, Cantabrian, Mediterranean and Adriatic Seas, as well as the Atlantic Ocean).

For this purpose, different technological processes are being optimised for the retrieval and recycling of nutrients with microalgae, advanced composting, biodrying, concentration and extraction by freezing, pyrolysis or chitin extraction, and many other techniques, which will make it possible to generate biologically based custom fertilisers, for local crops and conditions as well as for export.

Coordinated by NEIKER, the SEA2LAND project has 25 other participants in 11 different countries: Université de Liège (ULIEGE), Fibl Europe – Forschungsinstitut für biologischen Landbau in Europe (FIBL EU) and Universiteit Gent (UGENT) in Belgium; IPS Konzalting Doo Za Poslovne Usluge (IPS) in Croatia; Nutriloop Ou (NUTRI) and Eesti Taimekasvatuse Instituut (ECRI) in Estonia; Center Regional D’Innovation et de Transfert de Technologie Agroressources (CATAR), Institut national polytechnique de Toulouse (INPT) and Chambre D’Agriculture des Pyrenees Atlantiques (CAPA) in France; Università Politecnica delle Marche (UNIVPM), Università degli Studi di Milano (UMIL) and Società Cooperativa Pescatori Molluschicoltori (CO.PE.MO) in Italy; Aquabiotech Limited (ABT) in Malta; Gronn Gjodsel As (Grønn), Norsk institutt for biookonomi (NIBIO) and Norsk Landbruksradgiving Nord Norge (NLR-NN) in Norway; Instituto de Soldadura e Qualidade (ISQ) in Portugal; Barna SA, Caviar Pirinea SL, AZTI, Fundacio Universitaria Balmes (UVIC-UCC), Fertinagro Biotech SL, Iniciativas Innovadoras Sal (INI) in Spain; Forschungsinstitut für biologischen Landbau Stiftung (FIBL-CH) in Switzerland and the Instituto de Investigaciones Agropecuarias (INIA) in Chile.

SEA2LAND is part of the European strategy to drive the bioeconomy as the economic model of the future. It is also part of the Basque Government’s commitment to fostering the transition to the bioeconomy.



A member of the Basque Research & Technology Alliance (BRTA), NEIKER is a technology centre specialising in creating innovative solutions for the agriculture/livestock and forestry sectors. NEIKER’s primary lines of work include promoting operations’ sustainability and competitiveness, finding alternatives to mitigate the effects of the climate emergency on agriculture, driving the bioeconomy to reduce dependence on non-renewable raw materials and create new business activities, streamlining plant health protection in agriculture and reducing the use of antibiotics in livestock farming to minimise the impact of increased antibiotic resistance.

As an institution dependent on the Ministry of Economic Development and Infrastructure of the Basque government, NEIKER’s operations focus on providing answers and supporting the strategies designed by the Basque government for promotion, development and management in the Basque Country’s agriculture/livestock and forestry sector.