Biodegradation of furan-based composite resin by novel enzymes

Microbes like bacteria and fungi can grow on almost everything, including e.g. on a music CD made of aluminum and polycarbonate. How? By producing an optimal mixture of effective enzymes that degrade the material on which the microbes thrive. In this project we want to find and characterize microbes that have the ability to digest one of the most commercially successful but at the same time hard-to-degrade materials: furan-based bio-composite resin. To help the microbes to degrade this recalcitrant material, we first must open up the complex resin structure by using (mild) acidification, grinding, and/or UV light. Thus, with this project we aim to find an effective and sustainable way to safely and effectively dispose and recycle used bio-composite resins. Our findings will help to increase the circularity of bio-composite materials and as such decrease the environmental waste pressure.

Eindrapportage

Microorganisms such as bacteria and fungi are capable of colonizing a wide range of materials by producing tailored mixtures of enzymes that enable substrate degradation. In this project, we aimed to identify and characterize microbes capable of degrading furan-based bio-composite resin, a commercially important yet highly recalcitrant material.

The project was structured into four work packages: (1) screening for resin-degrading microorganisms, (2) optimization of pre-treatment and degradation conditions, (3) genomic and bioinformatic analysis of selected strains, and (4) identification and verification of key degrading enzymes.

Screening of over 100 bacterial isolates led to the identification of a Paenibacillus species, isolated from a termite jaw, with the highest degradation potential. Developing a reliable protocol to assess microbial growth on composite particles proved challenging but was successfully achieved. The isolate demonstrated the ability to grow on furan-based bio-composite, likely via conversion of furan-like compounds into alcohols.

Genome sequencing revealed a broad repertoire of carbohydrate-active enzymes, including candidate alcohol dehydrogenases potentially involved in resin degradation. Future work will focus on identifying the specific enzymes responsible for furan conversion and linking their activity to metabolite formation.

The project resulted in a successful collaboration between Leiden University, Avans University of Applied Sciences, and the industrial partner NPSP. In the next phase, this collaboration will hopefully be expanded to explore the use of microbial consortia for enhanced degradation of plant-based composites.