Researchers at the University of Jyväskylä in Finland have discovered that lignin, a natural polyphenol that gives plants structural strength, shows strong antimicrobial and antiviral properties. This substance is already produced in large quantities as a by-product of the wood industry. The findings suggest that lignin could replace synthetic antimicrobial agents in coatings, packaging, and other surfaces that require hygienic protection.

Extracting High-Purity Lignin from Biobased Sources

The team developed a simple water-based method to extract lignin from birch chips, wheat straw, and oat husks. This technique keeps the phenol content high and removes carbohydrate impurities. As a result, the material retains its effectiveness while remaining free from unwanted residues. Tests confirmed strong antiviral activity against non-enveloped enteroviruses and enveloped coronaviruses, including SARS-CoV-2. It also inhibited common bacteria such as Staphylococcus aureus and Escherichia coli.

How Lignin Fights Microbes

Scientists used biochemical and imaging techniques to understand lignin’s effects. For enteroviruses, lignin stabilises and aggregates viral particles, which blocks them from entering host cells or releasing their infective RNA. In the case of coronaviruses, electron microscopy showed that lignin disrupts the viral structure, making it harder for the virus to attach to and infect cells. The same research revealed that lignin damages bacterial cell membranes and causes internal aggregation, leading to a loss of bacterial function.

Sustainable Opportunities for Design

Because lignin is biobased, renewable, and widely available, it offers exciting potential for sustainable design. Architects and interior designers could use it in antimicrobial coatings for public buildings, healthcare facilities, or transport hubs. Packaging designers might apply lignin-based coatings to create biodegradable and microbe-resistant food or medical packaging. In the automotive sector, it could improve hygiene on interior touch surfaces. Product designers may integrate it into goods that require both durability and hygiene.

Collaboration and Future Outlook

The research was conducted in partnership with Spinnova Oy and CH Bioforce, both leaders in sustainable biomaterials. Together, they demonstrated that lignin can serve as a safe and circular alternative to synthetic chemicals. With further development, it could help create healthier environments and products while reducing environmental impact.

Source: University of Jyväskylä
Photo: Polina Tankilevitch