The green machine: commercializing microalgae products

By Rebecca Guenard

In This Section

February 2021

  • Companies have tried to garner a valuable product from algae for decades; current start-up investments hint that its greatest potential is still in the food sector.
  • Algae researchers are investigating its use as feed for agri- and aquaculture, while also continuing to optimize production of protein and omega-3s for humans.
  • Cutting production costs will be the key to maintaining market success.

Sales of plant-based foods are booming. The growing popularity of non-animal protein sources has led to their increased presence in grocery stores and fast-food restaurants. Even while venture capital investments declined due to the COVID-19 pandemic, start-ups focused on plant-based ingredients raised millions (https://tinyurl.com/plantbasedinvestments). In the Netherlands alone, there are more than 60 companies dedicated to the development of plant-based proteins (https://tinyurl.com/netherlandsplantbased). With so much lucrative potential in plant-based ingredients, some companies are trying to capitalize on algae as a unique source of protein and fatty acids.

Once primarily a niche ingredient, algae has gained recognition as a superfood. In addition to its nutritional value, algae is more sustainable than most types of agriculture. It can be grown without freshwater or pesticides and requires a tenth of the land for a comparable amount of biomass.

“Algae are the fastest growing plants,” says Navid Moheimani, director of Murdoch University, Algae Research and Development Center in Perth, Australia. “You cannot find anything that grows faster than these organisms.”

In the past two years, more effort has been focused on reducing the existing barriers that limit algae’s use in food applications. In Europe, especially, algae is most often associated with biofuels. Western countries are less familiar with the range of algae species or their various tastes, texture, color, and aroma. Food companies are trying to bring this segment of the population onboard. Unfamiliar consumers are slowly gaining experience with algae as food thanks to the popularity of drink powders and protein bars that derive nutrition from species like chlorella and spirulina. Will algae farming finally gain a spot in mainstream agriculture? This article discusses the possibility.

From food to fuel to food

Before the routine use of ammonia fertilizers after the second World War, conventional crops produced a lower nutritional density than they do today. The excessive energy required for conventional agriculture and the spike in the post-war population led researchers to consider using algae as a food source (https://tinyurl.com/algaehistory). Algae researchers at the time were unsuccessful at finding a species that Westerners would willingly incorporate into their diets. Concurrently, research on conventional farming led to more efficient production of animals and grain. As a result, the industry shifted the purpose of algae farms to fuel production.

The advent of genomics, in the early 2000s, expanded algae’s capabilities. Instead of being just a plant product, algae was viewed as a mini-factory. By modifying the DNA of single-celled species, referred to as microalgae, scientists coaxed the organisms to produce more triacylglycerols. Energy companies seized on microalgae as opportunity to offer an alternative to fossil fuels.

The reality of a depleting fossil fuel supply has since crystalized, yet biofuels have not proven cost-effective enough to gain long-term success. Nonetheless, a few energy industry hold-outs remain committed to producing fuels from algae lipids. In 2017, ExxonMobil announced that, with gene-editing, they could produce biofuels from algae at 10,000 barrels a day by 2025. However, they are the only major energy company still committed to microalgae biofuels. Other energy companies have given up on the pursuit.

metabolism in energy abundant vs. endurance exercise states
Fig. 1. Different cultivation systems for large-scale production of algal biomass. (A) Open pond systems use natural solar light as a source of energy. Closed systems can use either (B) natural solar light or (C) artificial light as an energy source. Source: Pathak, J., Front. Environ. Sci. 6:7,2018.

Growing algae in large open-air ponds that make fuel production affordable introduces several complications (Fig.1). It is costly to stir the ponds mechanically so that all the organisms get exposed to the sun for photosynthesis. Scientists also worry that genetically altered strains may escape into the wild and cause havoc on natural ecosystems. Some means of physical containment must be assured. Ultimately, algae is just too expensive to produce at the scale needed to get enough oil for the transportation industry.

“It is very hard to compete with fossil fuels when it comes to price, because you do not pay to build them.” says Moheimani. “You just extract them, crack them, and you have your products.”

Most experts discourage investing resources in microalgae biofuels when they could be directed to more viable types of sustainable energy, like solar and wind (https://tinyurl.com/algaebiofuelsmyth). Research and investment dollars are now shifting back to algae production for human consumption, which has a greater potential for both public good and higher profit margins.

Start-ups with intentions to produce algae as a plant-based food ingredient are gaining millions from private equity firms. Government-funded research collaborations between public companies and academia also became popular in 2020. The Dutch Ministry of Education and Science funded a collaboration known as the “Microalgae for food” project to investigate microalgae as a sustainable protein source (https://tinyurl.com/microalgaeforfood). Likewise, science institutes in New Zealand and Singapore are getting funding to evaluate protein production through a collaboration between their two countries. A growing number of organizations like these are investigating the many opportunities to increase algae’s commercial value.

Sustainable animal feed

One common area of interest for microalgae experts is animal feed. Microalgal biomass contains an abundance of nutrients compared to other common feeds like corn and soybean (Table 1). Depending on the species, microalgae produce high concentrations of polyunsaturated fatty acids (PUFAs), B12 vitamins, dietary fiber, sterols, antioxidants, and proteins (including all essential amino acids). While these are obviously crucial nutrients for humans, some researchers believe the best way to gain that benefit is indirectly—by feeding algae to animals.

Table 1. Comparison of the nutrition content in different types of commonly used animal feed. Source: Lum, K.K, et al. , J. Animal Sci. Biotechnol. 4: 53, 2013 .
Crude protein Carbohydrates Fat
Soybeans 37% 30% 20%
Corn 10% 85% 4%
Wheat 14% 84% 2%
Anabaena cylindrica 43–56% 25–30% 4–7%
Arthrospira maxima (spirulina) 60–71% 13–16% 6–7%
Chlorella vulgaris 51–58% 12–16% 14–22%
Spirogyra sp. 6–20% 33–64% 11–21%
Synechococcus sp. 73% 15% 11%

“The biomass we produce contains 50% protein,” says Moheimani. “Pig feed has only 5–10% protein.” His group is assessing whether the microalgae could be added to the pig feed as a powder to boost its nutritional impact.

Belgian researchers are investigating whether chicken feed can be improved in a similar manner. The ValgOrize project (https://www.valgorize.eu) was established by the European Regional Development Fund to enhance innovation in the algal sector. The primary focus of the project is on developing algae for human use, but researchers were interested in whether residues from such processing could be used as a supplement for chicken feed.

They conducted feed trials on both laying hens and broilers that included three different algae species. In a press release, the group reports that they are still analyzing the results in terms of digestibility of the feed and how it affects the taste of the resulting meat. They are also in the process of evaluating whether a 10% ratio of algae to feed is optimal as indicated by previous studies. However, they have determined that residual algae products need to be processed to reduce salt and mineral ash levels before they can be added to chicken feed (https://tinyurl.com/feedtrials).

“Without this treatment, the chicken’s ability to digest the algae could be negatively affected, eventually resulting in a decreased efficient use of protein and energy,” says Marta Lourenço, poultry researcher on the project.

Moheimani’s team has not yet conducted feed trials for pigs. Since algae are not normally a food pigs consume, they first conducted in vitro studies. The study results gave the team confidence that pigs can digest algal biomass, and in the coming year Moheimani says his group will perform pig feed trials—although he feels there is more potential for microalgae use as aquaculture feed.

“Aquaculture prawns do not taste the same as prawns that come from the sea,” Moheimani says. “That is because they do not eat their natural food when grown in prawn farms.” He says his group is working with industrial partners to supply the algae prawns naturally prefer to eat, and to determine if algae feed improves the flavor of farmed seafood.

In three decades, the world population is projected to reach 9 billion. Feeding livestock as efficiently as possible will be essential to ensure that humans have the protein and other nutrients they need. However, in terms of omega-3s, sustainability would improve if humans went directly to the source.

Remedy for overfishing

Earth will be out of seafood in 27 years, according to TheWorldCounts, a website that tabulates data associated with current global challenges (https://tinyurl.com/overfishingstats). This statistic may represent an extreme case, but there is general agreement among scientists that the current global demand on fisheries is unsustainable (https://islandpress.org/books/oceans-2020). To reduce pressure on the fish market and capitalize on high-value omega-3s, researchers and corporations are racing to optimize microalgae’s production of long-chain fatty acids.

Over the past decade, start-ups have established which microalgae species are most effective at producing omega-3s. Many of these small companies have since been acquired by the Dutch health and nutrition company, DSM (https://www.dsm.com). Production of principle fatty acids, such as gamma-linolenic acid, docosahexaenoic acid (DHA), arachidonic acid, and eicosapentaenoic acid (EPA), from microalgae are now a routine part of the billion dollar nutraceutical industry. These omega-6 and omega-3 fatty acids are primarily incorporated into infant formulas, but they have also been added to dairy products, table spreads, and mayonnaise.

Although certain species of microalgae produce 60% oil by weight (of which 40% is DHA) when fermented, solvent extraction and subsequent oil processing increases the cost of producing these omega-3s. Researchers are now focused on ways to bring microalgae production costs down.

Fertilization from waste

Algae may grow easily, but it does not grow everywhere. In the northern hemisphere, where sunlight is limited, microalgae production requires the controlled environment of closed photobioreactors. Moheimani says, in a climate like Western Australia algae can be grown more cost effectively in open ponds.

His group has optimized the value of their microalgae even further by growing the organisms on effluents from treated wastewater. “We developed a two-stage process,” says Moheimani. “First, a bacterial process anaerobically digests wastewater solids, and then the contaminant-free effluent is transferred to the algae pond where it acts as fertilizer.”

He says the process is not only a beneficial way to grow algae, but it could help small developing countries in Africa and southeast Asia, where water treatment to produce clean water is unaffordable. In addition, using wastewater to grow algae for profit prevents it from ending up in rivers and ground water, where it can produce a toxic algal bloom. “The future of the algae business is wastewater treatment,” Moheimani says.

Commercialization efforts

Whether the algae business truly has a future ultimately depends on consumers. Many algae products have so far experienced a commercial success rollercoaster. The edible oil produced by algae fermentation that sold under the brand name Thrive is an example. In 2019, the Netherlands-based food ingredient company, Corbion, was initially successful in selling the cooking oil in Walmart stores throughout the United States. Then, in August 2020, the company’s website read, “We are no longer selling Thrive Culinary Algae Oil. We were not able to achieve the commercial success needed to sustain the brand.” Corbion still makes an algae oil product, called AlgaWise, for food manufacturers and it is considering bringing an algae butter to market in the future. For now, they have no direct-to-consumer products, but that may soon change.

Corbion formed a partnership, in 2019, with the Swiss company, Nestlé. A spokesperson for Nestlé said the companies are in a development phase and considering potential applications. “We are actively exploring the use of microalgae as an alternative protein and micronutrient source for exciting plant-based products,” the spokesperson said in an email. Nestlé has already launched a few microalgae-centered products, including dog treats and human supplements.

After vexing the food industry for many years, is algae finally poised to become a mainstream source of food ingredients? The plant-based market boom and the COVID-19 pandemic might be the combination that pushes these organisms over the tipping point. Consumers aware that COVID-19 is a zoonotic disease (passing from animal to human) may be more inclined to adopt an animal-free diet, while supply-chain issues created by the virus have made shoppers even more conscientious about the traceability of their food ingredients. Finally, staying healthy and maintaining a rugged immune system are key consumer issues right now. Higher income consumers, who are less likely to have lost jobs due to shutdowns, may accept paying a little more for foods they believe offer the best health for their family. Rapid growth of the algae market is very likely in the next couple of years.

Rebecca Guenard is the associate editor of INFORM at AOCS. She can be contacted at rebecca.guenard@aocs.org.

Information

Distinct microalgae species for food—part 1: a methodological (top-down) approach for the life cycle assessment of microalgae cultivation in tubular photobioreactors, Schade, S. and T. Meier, J. Appl. Phycol. 32: 2977–2995, 2020.

Distinct microalgae species for food—part 2: Comparative life cycle assessment of microalgae and fish for eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and protein. Schade, S., et al., J. Appl. Phycol. 32: 2997–3013, 2020.

Chlorella vulgaris in a heterotrophic bioprocess: study of the lipid bioaccessibility and oxidative stability, Canelli, G., et al., Algal Res. 45: 101754, 2020.

Chapter 19–“Microbial production of polyunsaturated fatty acids as nutraceuticals,” by Ratledge, C. In Woodhead Publishing Series in Food Science, Technology and Nutrition, Microbial Production of Food Ingredients, Enzymes and Nutraceuticals, Editor(s): McNeil, B., et al., Woodhead Publishing, Pages 531–558, 2013.

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