The doctoral work of Clémentine Isembart demonstrates that microbial degradation offers a sustainable way to make use of feathers, an abundant but underused industrial by-product. Her research confirmed the feather-degrading abilities of two bacterial strains and revealed that they rely on different strategies. In addition, she isolated and characterized a new fungal strain capable of efficiently degrading feathers.
Think about the last chicken dinner you had. Now think about the feathers that chicken once wore. Where did they go?
Every year, the global poultry industry produces millions of tons of feathers, and most of them end up burned or buried in landfills. That's a waste in more ways than one, because feathers are made almost entirely of protein, a valuable raw material that could be put to much better use.
The catch is that feathers are built to last. They're made of keratin, the same tough protein found in your hair and nails, and in animal scales, claws and hooves.
Keratin is excellent at protecting animals precisely because it's so hard to break down. That same toughness makes feathers hard to recycle. Today's industrial methods for breaking down keratin rely on intense heat, high pressure or harsh chemicals, which use a lot of energy and can harm the environment.
Nature has its own solution. In the wild nature, feathers don't pile up forever. Certain bacteria and fungi slowly digest them. Clémentine Isembart's PhD research set out to understand how these microbes do it, and how we might harness them to turn feather waste into something useful.
Over four years, her work uncovered three key findings:
1: A little preparation goes a long way. Briefly treating feathers with pressurized steam (much like a pressure cooker) before handing them to bacteria makes a big difference to how well the bacteria can break them down.
2: Not all feather-eating bacteria are alike. Isembart compared a well-known feather-degrading bacterium with a newly discovered one that thrives in the cold, studying both how they perform as living cultures and how their digestive enzymes work. Cold-adapted microbes are especially interesting because they could make the process less energy-hungry.
3: A new fungal feather-eater. Isembart isolated and described, for the first time, a fungus that is remarkably good at degrading feathers.
– Together, these results show that when we can break feathers down efficiently, they stop being a troublesome by-product and become a resource. Instead of ending up in the incinerator, feathers could become ingredients for animal feed, fertilizers, or other valuable industrial products, Isembart says.
And the story doesn't end here. Building on this research, a new four-year project called Keranor has been funded at NMBU. A new team of PhD student and researchers will continue exploring feather degradation, with the goal of scaling these microbial processes up to industrial levels.
FACTS:
Clémentine Isembart
- PhD degree: NMBU's Faculty of Science and Technology. Funded by SFI Industrial Biotechnology.
- Previous education: Engineering degree in biotechnology/microbiology
- Title of thesis:
- Norwegian: Undersøkelser av mikrobiell nedbrytning av fjær: Innsikt i nye keratinolytiske bakterier og sopp
- English: Exploring Microbial Degradation of Feathers: Insights into Novel Keratinolytic Bacteria and Fungi
Clémentine Isembart will defend her PhD thesis on Friday 23 October 2026. Read more about the event here.