Carnivorous plants eat synthetic plastics

Researchers from Austrian institutions including acib GmbH, BOKU University, and the University of Applied Sciences Wiener Neustadt investigated the digestive fluids of pitcher plants Nepenthes alata and Sarracenia purpurea. Surprisingly, these fluids were able to break down common plastics like poly(ethylene terephthalate) (PET) and poly(butylene adipate-co-terephthalate) (PBAT).

The key enzyme identified was nepenthesin, an aspartic proteinase capable of hydrolyzing plastics into basic building blocks such as terephthalic acid (TPA). This enzymatic process is crucial for recycling, as it allows valuable components to be recovered and reused. Remarkably, plastic degradation increased up to tenfold when natural prey or the plant hormone jasmonic acid was present, suggesting that pitcher plants can adapt their digestive power to environmental stimuli.

Cutinases have long been associated with polyester hydrolysis, the role of proteases like nepenthesin in plastic breakdown is largely unexplored. Tests with recombinant nepenthesin confirmed its ability to degrade PET and PBAT at levels comparable to known cutinases. This discovery broadens the range of enzymes available for recycling and positions carnivorous plants as an underexplored but promising reservoir of biotechnological tools.

The implications are significant: enzymes derived from pitcher plants could pave the way for more efficient and sustainable recycling, reducing dependence on fossil resources and supporting a circular economy. This research (under H2020 UPLIFT project) highlights how local innovation can contribute to global sustainability, offering fresh hope for tackling one of today’s most pressing environmental challenges.