Algae could bring solutions to major challenges such as carbon sequestration and world hunger, provided we succeed in building an industrial sector.
The installation is a little artisanal, but the spectacle is no less fascinating. Specimens of Palmaria palmata twirl around in large columns of water, fed by a forest of flexible pipes, and unfold their amaranth-red tentacles following the bubbles that agitate the environment.
Arranged in a dark room, these vertical aquariums are surrounded by LED ribbons that focus the light on the wall of the tubes and attract the eye. The transparency and colorful shades of this algae, better known by the name dulse, are intensified. It might look like an art exhibit, but it's actually the Roscoff Biological Station, one of the most advanced research centers on algae in Europe, with around 100 scientists dedicated to studying the aquatic organism.
Philippe Potin, a senior researcher at the CNRS, says, "In nature, this species grows attached to rocks. But here, we are trying to study it in a suspended environment. Our goal is to soon be able to control its reproduction mechanisms."
Potin arrived at the Roscoff Biological Station about 30 years ago for his thesis, and has never left. The buildings — the oldest of which dates back to the 17th century — benefit from an exceptional geographical location with an unobstructed view of the bay and the island of Batz. To collect algae, researchers just go down to the beach at low tide. The station houses one of the richest collections of algae in the world, with nearly 9,000 strains.
I have never seen such a craze for this resource.
The center is equipped with a battery of freezers to preserve these specimens up to minus 150°C. "We can thus respond at any time to requests from researchers around the world and also from companies," says Potin. In addition to its fundamental research — which has enabled it to decipher the genome of some 50 algae species — the station works in close collaboration with industry players to improve cultivation techniques and extracting active ingredients and thus promote the emergence of a commercial sector.
"Since I have been working in this field, I have never seen such a craze for this resource," says Potin. In fact, all over the world, new applications are being tested in a wide variety of industries, from biomaterials to biopesticides, including health and human food. So many sectors are waiting for biosourced alternatives to replace their synthetic components.
Algae may suffer from a negative reputation from holidaymakers because of green tides, but in the eyes of some, it's the solution to major global challenges such as carbon sequestration. 50% of the air we breathe we owe to algae's photosynthesis properties that allow them to produce oxygen by consuming CO2. Algae's protein content also makes them a potential answer to world hunger. Moreover, to grow, they only need light and carbon. A real green gold! But we still need to remove the obstacles that prevent the sector from becoming more widespread.
The potential of algae is not new. After having extracted sodium bicarbonate and iodine for a long time, the coastal Brittany region has used algae since the 1960s for their alginates, the complex sugars that form their extracellular membrane. Alginates are used as texturizers or gelling agents in the food and hygiene-beauty industries. In the 1970s and '80s, the sector experienced a first boom in cosmetic uses.
But it is mainly as biofuels that these marine plants rich in oils have raised the most hopes. Jean-François Sassi, the head of microalgae processes and technologies at CEA Cadarache, has been involved in this adventure from the start.
"In the 2000s, the steady rise in oil prices gave credence to this green alternative and led to a real craze among many entrepreneurs, particularly in the United States," says Sassi. This was until the 2008 recession caused the price of oil to fall and the bubble burst. Even if TotalEnergies or Exxon continue their research on the subject, for the moment, we still don't know how to make an algal biofuel at an acceptable price.
Algae bread at Anhalt University of Applied Sciences, Germany — Photo: Klaus-Dietmar Gabbert/DPA/ZUMA
Caution, therefore, must be taken when talking about the promises of algae. Especially since far from forming a large homogeneous group as many imagine, these organisms have very different characteristics depending on their lineage. Variations are found not only between the two large families of macros and microalgae, but also within each of them. "There are as many genetic differences between a green alga and a red alga as there are between an elephant and a mushroom," says Philippe Potin.
Today, it is estimated that there are several tens of thousands of species of macroalgae present in nature and several hundred thousand species of microalgae in fresh or salt water. But only a very small number of them have been studied. And we exploit even less. One of the first challenges to go to an industrial scale is to be able to cultivate them. In Asia, where they are consumed fresh, we know how to produce them in mass. In fact, 96% of the 36 million tons cultivated each year are grown on this continent.
In France, the Breton coasts are home to one of the most beautiful forests of seaweed in the world with nearly 800 species. Frédéric Faure is the general manager of Algaia, one of the two major Breton alginate production plants. Algaia, which was acquired from Cargill in 2017, works with a fleet of 40 seaweed boats that harvest the resource offshore.
The company is mainly interested in Laminaria digitata and hyperborea. "With 40,000 tons per year, we are the first French harvester and the second in Europea, after one in Norway," says Faure. The entrepreneur is quick to point out that in France, the resource is managed in a very strict manner and that only 4 to 5% of the total is taken. But Philippe Potin is less reassured: "In some areas, such as the Molène archipelago, the pressure is much stronger."
Harvesting at sea poses other problems. This is the option chosen in particular by Olmix, a company created in the 1970s that has developed internationally by selling animal health products based on algae and clays. Founder Hervé Balusson says, "We collect and exploit 7,000 to 8,000 tons per year." The company uses service providers who harvest the resource on the shore in less than a meter of water using a tractor equipped with a conveyor belt.
Australia and New Zealand have lost nearly 50% of their seaweed forests.
But this activity is also subject to criticism. "Some local residents consider that it reflects a lack of political will to act on the causes of the eutrophication phenomenon responsible for green tides and that it should therefore be called into question," says Philippe Potin. In short, betting only on the natural resource whose quantity is likely to vary from one year to the next can, in the long run, prove risky. All the more so as, in Brittany, we are suffering from the proliferation of algae, elsewhere in the world climate change has rather reduced the resource. Potin notes that Australia and New Zealand have lost nearly 50% of their seaweed forests.
Fortunately, France has already begun the shift to cultivating, even if France is still far from the large Asian farms. With its two concessions of 150 and 200 hectares, located in Lesconil and Moëlan-sur-mer, Algolesko is already the largest seaweed farm in Europe. The adventure has not been easy for Philippe Legorjus, Algolesko's president. "It took time to master the techniques of seeding in our hatchery on land, as well as to develop the right "wire" device weighted at 20 meters deep and able to support the weight of crops and resist the assaults of storms," says Legorjus. But everything is now up and running.
This year, the farm harvested 150 tons, mainly wakame, kombu and sweet kelp. "We are aiming for 1,000 tons in three years," says Legorjus, a former commander of the French national police force, who also intends to develop multitrophic aquaculture in partnership with oyster farmers.
Unlike macroalgae which can be harvested, their microscopic cousins, invisible to the naked eye, have no other alternative to be exploited than to be cultivated. All who start the enterprise are confronted with the same problem: the productivity of the crop. And therefore its cost.
The AlgoSolis research platform in Saint-Nazaire, which originated at the University of Nantes, has worked on a wide range of cultivating equipment.
A seaweed farmer gathers edible seaweed that has grown on a rope, in Nusa Lembongan, Indonesia — Photo: Jean-Marie Hullot
"The most traditional method consists of placing "inoculums' in "raceways," large open basins exposed to daylight and equipped with a paddle wheel to create movement in the water. The microalgae will then develop by cell division," says Jack Legrand, a professor emeritus in process engineering, who is behind this equipment, which is unique in Europe.
But with this type of device, only 50 tons per hectare per year can be produced on average. This is not enough for applications that require large volumes such as biofuels, as it would require monopolizing kilometers of crops. This explains why, for the time being, microalgae are mainly used in high value-added applications such as omega 3-based food supplements, in the form of pigments for the food industry or in cosmetic products.
But cultivation techniques are evolving. Some manufacturers are already using "photobioreactors' with vertical or tubular structures. This is the case of Microphyt, which specializes in ingredients for nutrition and cosmetics and has just received a 15 million euro grant from the European Commission and the Bioindustries Consortium to build the largest microalgae biorefinery in the world. "The advantage of these devices is that they take up much less land," says Jack Legrand. But we still have to succeed in supplying them with light and carbon. To make 1 kilogram of biomass, you need 1.6 kilogram of CO2. The AlgoSolis platform has patented a system of cultivation on a film of water that allows much higher yields, up to 20 grams per liter against 1 to 2 grams for "raceways."
The start-up Inalve claims to go much further. Based in the Ecovallée region of the Var plain, Inalve has taken over a patent from the French National Institute for Research in Computer Science and Control (Inria) to develop a device capable of producing up to 200 grams per liter. The process uses biofilms installed on rollers that rotate in basins. The company is not afraid to target the aquaculture and animal feed markets, for which it will have to produce large volumes.
CEO Christophe Vasseur says they plan to launch the commercial farm on several dozen hectares by 2024. "23 tests are underway with industrial partners to evaluate the effectiveness of our microalgae concentrate, rich in proteins, lipids and complex sugars," says Vasseur.
The photobioreactors developed by Suez in partnership with Fermentalg are based on an even different model. Initially, the two partners were primarily interested in developing systems that could capture carbon and clean up the atmosphere. Demonstrators were installed in schoolyards and on industrial sites. But the CO2 resource proved to be either too dilute or too polluted to consider microalgae production systems.
Through their new joint venture CarbonWorks, Suez and Fermentalg are now focusing on the market for methanizers that produce 90% pure carbon. "We have just installed the first pre-industrial equipment with a capacity of 10 m3 at the Cestas methanization site in Gironde," says Jérôme Arnaudis, head of air quality activities at Suez. In addition to limiting carbon emissions, these systems will make it possible to produce a microalgae used by the Gironde-based start-up Immunrise in a biocontrol product for vines, a real virtuous circle!
Farmers are waiting for alternative solutions to chemical inputs.
But the development of the sector will also necessarily involve the identification and extraction of new active ingredients. Here too, things are moving forward. In fact, the Olmix and Algaia plants have become real biorefineries.
"Yesterday, we only used alginates, which is 20 to 30% of our biomass," says Frédéric Faure. "Today, we are able to extract about 10 molecules of interest with a wide range of applications. The extraction process is designed so that the residue from one operation becomes the raw material for the next."
The two companies have thus been able to diversify into the biopesticides and biostimulants market for agriculture, among others. "Farmers are waiting for alternative solutions to chemical inputs," says Hervé Balusson.
In parallel to these generalist approaches, we are also seeing an increase in the number of start-ups that are betting on specialized applications, both in macro and microalgae. Eranova has set its sights on the packaging plastics market for the food and cosmetics industry. Located in the port area of Fos-sur-Mer, this company not only wants to use the green algae that washes up in the Etang de Berre but also to develop its own production in ponds. CEO Philippe Lavoisier says that "For the moment, we have installed a demonstrator on one hectare and a small biorefinery of 500 tons. But we are in advanced negotiations to have 50 hectares on the site with an industrial unit capable of processing 28,000 tons." Eranova is thinking big.
Olgram, on the other hand, will only need a few 100 kilos of active ingredient to serve its market. This start-up is targeting a medical application. Managing director Pierre Rochete says, "We have taken up the research of a team from the University of Nantes, which has demonstrated the beneficial effects of a molecule extracted from Ulva armoricana on immunosuppression following cranial trauma." Even if they are still in preclinical studies, this is a market that potentially includes nearly five million people in Europe and the United States.
Algama, for its part, is digging into the food sector. Until now, seaweed was consumed either as a condiment for salads or pasta, as a powder in chips or bread or as a texturizer, for example in ham. But this start-up has found a way to make a microalgae-based powder that can replace eggs in the manufacturing of mayonnaise, buns or cookies. "We are also working on recipes for salmon or vegetable tuna that would have the same texture and energy content as the originals," says Jean-Paul Cadoret, the company's scientific director.
The sector also needs convinced investors.
For this expert, who is also president of the European Algae Biomass Association, the development of the sector will come from this range of new applications. "It is the added value brought by these products that will allow us to increase the volumes," says Cadoret. However, many of these projects are still at the pre-industrial stage. "To grow, the sector also needs investors who believe in its development potential," says Philippe Legorjus.
To accelerate the process, the Lloyd Register Foundation, in partnership with the United Nations Global Compact, has just launched an international call for projects in all fields of algae exploitation. "We are going to try to convince major food and packaging companies to join us in co-financing," says Philippe Potin, who coordinates the steering and selection committees on behalf of the CNRS, which includes major groups such as Nestlé and Metro.
In another field, the Oceans 2050 Foundation, created by Alexandra Cousteau, has launched a study of some 20 farms around the world to establish scientifically that the cultivation of algae allows the burial of a large quantity of carbon in the underlying sediments. "We will then be able to build a carbon credit system that would allow large companies to invest in this type of farm," says the granddaughter of the famous commander. This is the sine qua non condition for the emergence of a complete ecosystem, allowing this resource to finally live up to its undeniable promise.