■Industrial Use of Paramylon

Paramylon is a crystalline β-1,3-glucan believed to be produced exclusively by microalgae Euglena (commonly known as "Midorimushi" in Japan) and its close relatives. β-1,3-glucans are polysaccharides found in various sources, including fungi, and are widely recognized for their immunostimulatory properties. Paramylon, found in Euglena, is also considered to possess similar properties due to its β-1,3-glucan structure, and it has been studied for a long time.

In 2005, Euglena Co., Ltd. made it possible to easily ingest paramylon by supplying large-scale cultivated Euglena as a food ingredient. This industrial use of Euglena led to increased research on the functionality of paramylon itself, creating demand for purified paramylon. Paramylon has been increasingly recognized for its potential in the healthcare sector, and research on its functionality has resulted in a push for both its supply through large-scale production and its application in various areas.

Notably, paramylon has been examined for its potential as a functional food product with relatively high added value, focusing on healthcare benefits. Studies have indicated its potential in immune modulation, including alleviating symptoms of influenza, reducing symptoms of atopic dermatitis, and alleviating rheumatoid arthritis. Paramylon is being explored as a functional ingredient in healthcare products.

The introduction of paramylon and paramylon-rich products into the market, particularly as functional foods, has created new market segments. Major retailers have initiated the development and sale of products containing Euglena, emphasizing the functionality of paramylon and the utility of Euglena in healthcare goods.

■Use of Purified Paramylon

To industrially utilize extracted paramylon, the process involves cultivating Euglena and then extracting and separating paramylon. Typically, Euglena obtained through regular large-scale cultivation contains only about 20% paramylon by dry weight. The remaining approximately 80% needs to be removed as impurities for extraction and purification, which can be an inefficient process. Various methods have been developed by different companies to increase the paramylon content in Euglena, making it possible to stably cultivate and supply Euglena with higher paramylon content. Technological advancements in this area have progressed.

Purified paramylon retains the same functional effects as using the entire Euglena powder. Additionally, the purification process opens up new potential applications. Moreover, paramylon has been demonstrated to have wound-healing effects when used as a medical device material.

Euglena is now supplied in the form of dried powder, primarily in the health supplement market. By using this edible powder for paramylon extraction, it is possible to obtain paramylon of food additive grade without affecting its suitability as a food ingredient. While other β-1,3-glucans are more challenging to purify, the ability to create food-grade paramylon expands its potential applications.

■Positioning of Paramylon Among Euglena's Functional Components

When using Euglena as a health food ingredient, paramylon is considered its primary active component. Besides paramylon, Euglena contains various nutritional components from both animal and plant sources. However, it is not yet clear whether Euglena-specific functional effects exist among the non-paramylon components.

Our team has pioneered Euglena's genome editing technology globally. During this process, a gene known to be involved in paramylon synthesis (EgGSL2) was chosen as one of the target genes for genetic modification. As a result, the mutant strain demonstrates an inability to accumulate paramylon. Previously, it was challenging to investigate the functional effects of non-paramylon components in Euglena because paramylon was always present when Euglena was cultivated. However, by utilizing this strain, we hope to clarify the functional effects of non-paramylon components in Euglena.

■Immunomodulatory Activity of Paramylon

Paramylon is known to be a crystalline β-glucan with potent immunomodulatory activity. Various receptors on immune cells, including Dectin-1, Toll-like receptors, complement receptor 3, scavenger receptors, and receptors involved in biological responses such as lactosylceramide and elicitor-specific responses, recognize paramylon. Studies have indicated the immunomodulatory potential of paramylon in various contexts, including inducing stress resistance in Artemia used in fish farming, paramylon nanofiber formation for natural immune activity in human lymphocytes, and anti-fibrotic effects in mouse liver damage.