Optimising strategies to produce at scale

Microalgae are amazingly versatile. They are a source of omega three fatty acids, antioxidants, and other useful compounds and they have a number of useful applications including in the food, feed, and pharma industries as well as in bioplastics, biostimulants, and biopesticides. They can also be deployed to remove nutrients such as nitrogen and phosphorus from effluents produced by water treatment facilities or fish farms.

However, production of microalgae at scale is often constrained by unfavourable economics. Notwithstanding this, companies convinced of the potential of microalgae have been established from the north to the south of Europe. Their optimism is based partly on the knowledge that microalgae can contribute to several European Commission strategies such as the European Green Deal and the Farm to Fork strategy and are highlighted in the EU’s strategic guidelines for sustainable aquaculture. Further emphasising the importance the European Commission places on algae was the adoption of the algae initiative towards the end of 2022.

Close collaboration with educational institution

About a decade ago, algae were generating a lot of headlines in the US about their potential to produce biofuel in volumes that could even compete with oil. This did not materialise and funding for the sector largely evaporated as disappointed investors decided that algae were good for nothing. Against this backdrop, Power Algae was founded in Estonia in 2013 by two students, Dr. Liina Joller-Vahter and another graduate student working towards their Ph.Ds in economics at the University of Tartu. Both of them were interested in innovation-related topics and, after reading the literature about microalgae, started to put together a team with expertise in mechanical engineering, biology, chemistry, and other relevant fields. The main partner since then has been the Estonian University of Life Sciences. The collaboration with the university and the inclusion of mechanical engineers on the team meant that Power Algae’s focus at the beginning was on the design and construction of equipment to cultivate microalgae rather than downstream processing, which has come on the agenda more recently.

Over the last decade the company only produced microalgae in small volumes but it has accumulated a lot of knowledge and now is in a position to start upscaling. Power Algae has generated revenues by providing expertise in bioremediation, designing circular systems, evaluating market potential of blue bio technologies, and in other related fields, but it has not produced and sold algae biomass on a large scale. The company does not focus on a single sector but is interested in food, feed, nutraceuticals, and pharmaceuticals. Microalgae are a potential source of important nutrients such as proteins and fatty acids but, she cautions, it is to be taken in very small doses, as a tablet perhaps or through enriching another food product, but not consumed “as a porridge”. People in Asian countries have been eating macro- and microalgae for centuries, and there may be pockets of Europe which have a history of algae consumption, but in general European production and consumption of algae is miniscule.

Legislation does not cater specifically to the algae sector

Algae production for food purposes falls under the novel food regulation in Europe which currently only allows a few varieties of algae to be consumed, though this is changing gradually. According to Dr Joller-Vahter many producers feel that they could belong under aquaculture or under agriculture or under processing but that none of the regulations are actually tailored to the algae sector.

As a feed, microalgae are ideally suited to juvenile fish since it is often part of their natural diet in the wild. But trials include testing the benefits of microalgae in feeds for cattle, pigs, and poultry. The presence of red pigments in some strains of algae gives egg yolks and also salmon flesh a darker colour. Dr Joller-Vahter says that the use of algae in feeds is of particular interest because it is also supported by the European Commission, which would like to find alternatives to soy protein in the feed formulas used both in aqua- and agriculture. But competing on the market for protein, which is traded like a commodity today, is very difficult for producers of microalgae. That said, juvenile fish in general and adults of certain fish species are potential markets for feeds enriched with microalgae, which beyond being a source of lipids and proteins also have antimicrobial components. Hence, a feed formula with a microalgae component serves not only nutritional purposes but also enhances fish health. At Power Algae several species of microalgae are being studied. There are hundreds of strains of microalgae that appear in nature of which only a very few have been scientifically investigated. At Power Algae the species being studied include both native and exotic varieties.

The focus on cultivation systems throws up its own challenges. Microalgae can be grown in ponds or raceways as well as in closed systems. Since the climate in Estonia is not favourable to grow microalgae in ponds or raceways, Power Algae uses closed systems called bioreactors. These come in different shapes and sizes, starting from a few litres and reaching several hundreds of cubic metres for full scale production. Here both autotrophic and heterotrophic (those that do not need light for growth) microalgae can be cultivated. When necessary, LEDs provide the light and nutrients and carbon dioxide are added to the bioreactor to stimulate growth of the microalgae. What is important is that all the microalgal cells have access to all these elements, a condition achieved by optimising the circulation of the medium in which the nutrients and the carbon dioxide are dissolved. The microalgae are unicellular organisms and one of the challenges is to ensure the culture does not get contaminated with, for example, another strain of microalgae.

The saving on cooling partly compensates for the lack of sunlight in Estonia

Microalgae are cultivated in bioreactors in several countries in Europe. Southern countries have the advantage of bountiful

Power Algae Ltd.

Riia 181a

Tartu 50411 Estonia

Founder and co-owner: Dr Liina

Joller-Vahter

Area of activity: Design of equipment for microalgae cultivation and processing sunlight and a long warm summer season. On the other hand, cooling costs need to be taken into consideration as ambient temperatures can rise to well over 30 degrees. Most currently commercially cultivated microalgae thrive at temperatures between 15 and 25 degrees. In the north there is not enough sunlight, so LEDs that run on electricity must be used, which is a cost factor. But cooling, which demands energy and water, is not an issue. Heating too is relatively inexpensive as, at least in Estonia, there are abundant sources of excess industrial heat which can be used for the production. When the microalgae is to be harvested several techniques are available, says Dr Joller-Vahter, and the choice of method depends essentially on which is the most cost efficient in terms of both time and energy. But it is also influenced by what the biomass will be used for afterwards. At Power Algae researchers are looking at ways to increase the biomass and at the same time also at ways to increase the content of a specific component within the biomass, for example, lipids, proteins, or pigments. After almost a decade of building up our knowledge and international collaboration network we are now starting to scale up our own production, and are open for collaboration on the feed, food and pharma applications, says Dr Joller-Vahter.

Uses of microalgae: Ingredients for food, feed, and pharma; water treatment; carbon capture

Employees: 3

Main partner: Estonian University of Life Sciences