The extraordinary potential of microalgae – already known for the production of food and renewable energy, in the name of carbon farming (1,2,3) – is also revealed in agriculture, aquaculture, upcycling of wastewater and greenhouse gases.
1) Microalgae in agriculture
The health of the soil it is essential for food production and the ecosystem services it provides (e.g. carbon sequestration, water purification, pest control, biodiversity protection).
60-70% of the soils European countries is however degraded, and it is therefore necessary to drastically reduce the use of synthetic pesticides, herbicides and fungicides. (4)
Microalgae can favor this ecological transition in agriculture, as highly effective biostimulants in stimulating plant growth and increasing resistance to pathogens and various other attacks. (5,6) As has been demonstrated, among other things, in the rescue of olive trees affected by Xylella Fastidiosa. (7)
1.1) SABANA, the research project in Horizon 2020
The EU research project SABANA – in Horizon 2020, coordinated by Professor Gabriel Ancién (University of Almeria) and the biotechnology company Algaenauts – allowed to deepen the potential of different strains of microalgae and cyanobacteria (anabaena, Arthrospira platensis, Chlorella vulgaris R-117, Dolichospermum, Nannochloropsis Cadiz, Nostoc common, Scenedesmus almeriensis, Scenedesmus obliquus, as well as microalgae native to Tunisia) in agriculture.
A biorefinery integrated on a large scale has thus been created, to cultivate microalgae by means of upcycling of seawater, wastewater and centrifuges, slurry and pig manure. The biomasses are then used to produce biostimulants, biopesticides and feed additives, as well as biofertilizers and feed for aquaculture. Farmers who have tested microalgae-based products have assessed their greater efficiency compared to the corresponding synthetic agrochemicals.
2) Microalgae in aquaculture
Necton SA has been producing microalgae in Faro (Portugal) for over 25 years. Its founder João Navalho tells Euronews that microalgae play 'a very important role in what could be the future in Europe', for human and animal nutrition that is less harmful to the environment. (8) Researchers of IPMA (Portuguese Institute of Sea and Atmosphere), in the Olhão aquaculture research station, are in turn studying the use of various strains of microalgae in the diet of adult fish.
Fish nutrition breeding with microalgae, in addition to responding to their natural diet, allows you to:
- save the use of wheat-based feed. Thus reducing the consumption of agricultural land for feed production,
- 'improve the well-being of animals by strengthening their immune system and resistance to stress', in comparison with the administration of fish oils and meals (Sara Castanho, researcher, IPMA). (8)
3) Upcycling of wastewater and greenhouse gases
A recent study of Nanchang University in China (P. Xu et al., 2023) demonstrates the extraordinary ability of microalgae to absorb CO2 and simultaneously produce useful biomass for different applications. Microalgae can fix carbon in quantities 10-50 times greater than that of terrestrial plants and most of them are able to absorb various elements including CO2, carbonate and bicarbonate.
The ability of microalgae to absorb large quantities of carbon and nitrogen also allows them to be used to remove exhaust gases that contain these elements. Studies show that the cultivation of microalgae in a system where renewable energy and wastewater are used also allows for the production of biomass with very low or even negative carbon emissions. (9)
4) Biopolymers from microalgae. The research project Nenu2PHAr
Nenu2PHAr is the European research project that is perfecting the production of natural polymers starting from marine bacteria and sugars extracted from microalgae. The production of bioplastics is essential to reducing greenhouse gas emissions in the production of plastics from fossil fuels. (10) Although the patterns of consumption, reuse and recycling of plastics themselves need to be reformed, to mitigate thepollution of the seas and the ubiquitous one from microplastics. (11)
Sustainability of bioplastics from microalgae – like any other of their applications starting from food, in turn tested in the EU research project ProFuture (12) – is also linked to the fact that the production of raw materials does not require the use of arable land . And the properties of the bioplastics that are obtained - assures Pierre Lemechko, biotechnology researcher at IRMA (Institut Régional des Matériaux Avancés, France) – are comparable to traditional plastic. (8)
Dario Dongo and Alessandra Mei
Cover image from SAVANA EU research project, overall concept
(1) Dario Dongo. ProFuture, microalgae to feed the planet. The EU research project. GIFT (Great Italian Food Trade). 18.6.19
(2) Dario Dongo, Andrea Adelmo Della Penna. Algae and microalgae for food use in Europe, the ABC. GIFT (Great Italian Food Trade). 14.11.22
(3) Dario Dongo, Giulia Pietrollini. Algae and microalgae. Carbon farming and CO2 upcycling. GIFT (Great Italian Food Trade). 18.1.23
(4) Dario Dongo. Soil protection, 2030 strategy. ABC. GIFTS Great Italian Food Trade). 6.12.21
(5) BK. González-Pérez, AM Rivas-Castillo, A. Valdez-Calderón, MA Gayosso-Morales. Microalgae as biostimulants: a new approach in agriculture. 26.11.2021, doi: 10.1007/s11274-021-03192-2. PubMed. https://pubmed.ncbi.nlm.nih.gov/34825262/
(6) Dario Dongo, Andrea Adelmo Della Penna. Animal husbandry, algae and microalgae to prevent the use of antibiotics. Algatan. GIFT (Great Italian Food Trade). 9.9.20
(7) Dario Dongo, Andrea Adelmo Della Penna. Biostimulants in olive growing, the organic revolution. Scientific review. GIFT (Great Italian Food Trade). 14.5.21
(8) Denis Loctier. Researchers in Europe turn to microscopic algae for answers to our environmental problems. https://www.euronews.com/green/2023/01/31/researchers-in-europe-turn-to-microscopic-algae-for-answers-to-our-environmental-problems Euronews. 3.2.23
(9) P. Xu, J. Li, J. Qian, B. Wang, J. Liu, R. Xu, P. Chen, W. Zhou. (2023). Recent advances in CO2 fixation by microalgae and its potential contribution to carbon neutrality. ScienceDirect, doi: 10.1016/j.chemosphere.2023.137987, https://www.sciencedirect.com/science/article/abs/pii/S0045653523002540#preview-section-abstract
(10) Dario Dongo, Alessandra Mei. Plastic and greenhouse gas emissions, an emergency to be prevented. Scientific study. GIFT (Great Italian Food Trade). 9.2.20
(11) Marta Strinati, Dario Dongo. Microplastics in our lungs too. The British study. GIFT (Great Italian Food Trade). 12.4.22
(12) Dario Dongo. ProFuture, microalgae to feed the planet. The EU research project. GIFT (Great Italian Food Trade). 18.6.19