19 June 2026
In the future, microorganisms could help return hard-to-recycle plastics back into the recycling loop. Nick Wierckx, a molecular biologist at Jülich, explains the opportunities offered by biological recycling processes and the challenges of a truly circular economy.
The German federal government is driving the transition toward a resource-efficient economy: Through the National Circular Economy Strategy (NKWS), the recently unveiled action plan for its implementation, and a new Packaging Act, the goal is to use raw materials more efficiently, prevent waste, and keep materials in the cycle for as long as possible. Plastics, in particular, are a key focus. In the future, packaging is to be more easily recyclable, contain more recycled content, and achieve higher recycling rates.
Microorganisms as the Key to Sustainable Plastic Recycling
How can science and technology help achieve these goals? Biotechnology could play an important role. Researchers are working on processes to break down plastics and enable microorganisms to utilize their components for the production of new chemicals and materials. Nick Wierckx, head of the Microbial Catalysis Group at the Institute of Bio- and Geosciences at Forschungszentrum Jülich, is working with his team to develop such biological approaches for a more sustainable chemistry.
Biotechnology for a Circular Economy in the Plastics Sector
Wierckx also recently discussed the opportunities and challenges of a circular plastics economy together with colleagues from other Helmholtz centers at the parliamentary breakfast hosted by the Helmholtz Forum Earth and Environment project SPHERE. The Helmholtz Project brings together and expands knowledge on the end-of-life management of plastics in order to combat global plastic pollution. In this interview, Weirckx explains how microbial biotechnology can contribute to a functioning circular economy.
The German government aims to increase the recycling rate for plastic waste to 80 percent by 2030. From a scientific perspective, how realistic is this target with the technologies currently available?
Nick Wierckx: Technologically, I think it's possible. There are many exciting developments going on: Chemical recycling, which breaks plastic down into its basic components for purification and re-polymerization; Pyrolysis, which converts plastic back to oil. And of course biological recycling, which feeds plastic to bacteria, thereby providing it as a raw material for biotechnology. But it's also a question of economics: how much are we willing to pay for it. These technologies need to be further developed so that they can be put to practical use in a way that can compete with virgin plastics.
How Bacteria Can Break Down Hard-to-Recycle Plastic Waste
Many plastics are difficult to recycle or lose quality during the recycling process. What opportunities does biotechnology offer for returning these materials to the circular economy more effectively? How can microorganisms help transform plastic waste into valuable raw materials or new products?
NW: In nature, everything is mixed and natural materials like wood and fibers are composed of different materials and qualities. Yet, everything is recycled in the end. We essentially use this biological process to recycle plastics. By breaking down the plastics and feeding the resulting mixtures to bacteria, we can convert waste into new biotechnological products. Since we break down the plastic anyway, it doesn't matter that the quality is degraded.
Packaging for Effective Biological Recycling Processes
The proposed legislation emphasizes recyclable, reusable, and in some cases compostable packaging. From a research perspective, what characteristics should future packaging have to enable biological recycling processes to work most effectively?
NW: First of all, it is important to keep in mind the waste hierachy: We should try to avoid that plastic waste is generated in the first place. Do we really need to use so much plastic? Or can we reuse packaging by e.g. deposit schemes. If this is not the case, recycling comes into play.
Here, it is crucial to reduce the complexity. Simple, mono-material packaging with as little additives as possible are best to recycle. If complexity can't be avoided due to e.g. food safety concerns, then it would be good if the materials are all biodegradable, so they can be biologically recycled.
Bio-Recycling as a Building Block of the Plastic Circular Economy
Looking ahead ten years, what role do you expect biotechnological approaches and microbial processes to play in a fully functioning circular economy for plastics?
NW: It will be exciting to see what will happen in the future. I can imagine bio-recycling to contribute one solution among many for complex products that combine natural materials with plastics. Examples could be food containers out of coated paper, or textiles that mix cotton and polyester.
And from a circular economy perspective, it is also important to think about where the raw material comes from. Here, biotechnology can also play a role by enabling production of plastics and plastic building blocks from renewable resources, rather than from oil that we have to import with all the consequences we are facing today.
Looking beyond individual technologies, what do you think is still missing to make a truly circular plastics economy a reality? Where do you currently see the most promising developments?
NW: One of the biggest challenges is that we still tend to think about recycling as a single step at the end of a product's life cycle. In reality, a circular economy requires an entirely new way of connecting material flows, production processes, and energy systems. We need technologies that can handle complex waste streams and transform them into valuable resources for new products.
This is the central idea behind the Werner Siemens Foundation centennial project Catalaix, that we recently joined. This multidisciplinary consortium focuses on integrating research from catalysis, to devices and processes, to the system of global material cycles, to drive the transition to a multidimensional circular economy.
