Microalgae: an innovative tool for bioeconomy

The main speaker of the seminar was Irina Adarchenko, a graduate student from the Institute of Ecology at RUDN University with the presentation “Innovative Tools for Bioeconomy: the case of microalgae production.”

Production

Microalgae production is a key source of valuable bioproducts, including proteins, lipids, carbohydrates, vitamins, and various other beneficial compounds. However, their extraction involves a complex, multi-stage process.

First, microalgae are cultivated under controlled conditions, whether in open ponds, closed photobioreactors, or fermenters. The biomass produced this way is then harvested and dehydrated. To release the contents of the cells, it is necessary to remove the cell walls. This can be done through mechanical, chemical, or enzymatic methods. Next step is the extraction process, where organic solvents, alkalis, acids, and enzymes are utilized to isolate specific compounds. The resulting extracts are then separated and purified to obtain the product.

For example, high-purity proteins are extracted using alkaline extraction or enzymatic hydrolysis, while Omega-3 fatty acids are obtained through lipid extraction with organic solvents followed by separation. Vitamins and natural pigments are extracted using specialized solvents. Antioxidants and other specific compounds are extracted using solvent extraction and chromatography

Areas of use

Proteins, lipids, and carbohydrates derived from microalgae have potential applications in the food industry, for example, as additives, ingredients for functional foods, and aquaculture feed. Vitamins, pigments, antioxidants, and other bioactive compounds can be used in pharmaceuticals, cosmetics, and dietary supplements. In the energy sector, lipids are used for the production of biodiesel, while carbohydrates are used for bioethanol. In agriculture, microalgal biomass is becoming a biofertilizer. Furthermore, microalgae are used for wastewater treatment and in the production of biodegradable plastics.

Bioeconomy uses microalgae for several reasons:

1. Microalgae exhibit rapid growth rates, allowing for the production of biomass in significant quantities in a short time frame.
2. It does not require arable land, as they can be cultivated in controlled environments.
3. Microalgae are capable of absorbing CO2 from the atmosphere, helping to mitigate the greenhouse effect.
4. It also plays a crucial role in bioremediation, cleaning up wastewater and contaminated sites.
5. The diverse range of microalgal species, each with its unique composition, opens up avenues for a wide variety of products.

Microalgae provide proteins and micronutrients to the population, addressing the global challenge of food security. They also play a crucial role in ensuring energy security by offering renewable sources of biofuels, which helps reduce dependence on fossil fuels. The exciting prospects for using microalgae are tied to advancements in cultivation, processing, and scaling up production technologies. In the future, we can expect the emergence of new bioproducts derived from microalgae, as well as an expansion of their applications across various industries.

Technologies for cultivating microalgae

There are several technologies for cultivating microalgae.

• Open ponds represent the most cost-effective option, although they do not allow for complete control over growth conditions.
• Closed photobioreactors provide more regulated environments, ensuring higher productivity and biomass purity, but they come with a significantly higher price tag.
• Hybrid systems blend elements of open ponds and closed photobioreactors to optimize the production process.
• Additionally, fermenters are used for cultivating certain types of microalgae in the dark, utilizing organic substrates for growth.

The implementation of these technologies in production comes with a range of challenges and obstacles. The high costs of production require substantial investments in equipment and infrastructure. Additionally, the low productivity of certain strains and processing methods needs further optimization and scaling efforts. Cultivation and processing processes are highly energy-intensive, highlighting the need to develop more efficient and environmentally friendly solutions. Another critical concern is the risk of water body eutrophication when microalgae are used in bioremediation, which necessitates strict monitoring and regulation. On top of this, scaling up laboratory innovations to industrial production remains challenging, compounded by logistical issues and difficulties in storing biomass and derived products.