# Pac-Man Enzyme Breaks Down Bioplastics and Antibiotics, Scientists Find

> Researchers at the University of Konstanz have discovered a novel enzyme that simultaneously degrades bioplastics and cleaves beta-lactam antibiotics, offering a dual solution to environmental challenges.

By PrimaryBrief newsroom · Published 2026-10-21T05:18:39.735502Z
Canonical: https://primarybrief.com/article/pac-man-enzyme-breaks-down-bioplastics-and-antibiotics-scientists-find-a1aecba3

Scientists at the University of Konstanz have discovered a novel "Pac-Man enzyme" that can break down several types of bioplastics within 250 to 330 days and also cleave beta-lactam antibiotics [1][2][7][8]. This discovery, announced on September 2, 2026, reveals a dual environmental function for a single enzyme [6][8].

This enzyme provides new insight into how microorganisms adapt to synthetic materials, opening doors for developing strategies to combat plastic waste. The enzyme's ability to neutralize antibiotics also points to a potential link between plastic degradation and the environmental spread of antibiotic resistance [1][2][6].

## What the records show

Microbiologist Harry Lerner, then a postdoctoral researcher at the University of Konstanz, and Professor David Schleheck led the research that identified this enzyme [2][9]. Their findings were published in The ISME Journal on September 2, 2026 [6][8]. The enzyme, dubbed the "Pac-Man enzyme" due to its wide-open active site, is a bacterial family-VIII esterase [2][8][11]. It is held firmly to the bacterial cell surface by a lipid anchor, which may prevent its loss in aquatic environments and increase catalytic efficiency [8][11].

The discovery originated from experiments where thin films of long-chain aliphatic polyesters (LCAP), a plant-oil-based bioplastic developed by chemist Stefan Mecking's team, were buried in the humus layer of the university's botanical garden forest [2][7][9][12]. Parallel laboratory experiments involved mixing powdered plastics into soil samples and monitoring carbon dioxide release, which signals microbial consumption [7][12]. Microscopic images of retrieved plastic films showed tiny, bacteria-shaped pits, indicating microbial activity [5][7][9].

In soil tests, the "Pac-Man enzyme" facilitated the complete degradation of several bioplastic materials, including LCAP, PHBV, and PCL, within approximately 250 to 330 days [7]. In contrast, conventional high-density polyethylene (HDPE) plastics remained largely unchanged under the same conditions [7]. Beyond plastic degradation, the enzyme also cleaves beta-lactam antibiotics such as penicillin G and ampicillin, rendering them unable to kill bacteria in laboratory settings [4][9]. This dual activity is attributed to its structural similarity to beta-lactamases, which are enzymes bacteria use to neutralize antibiotics [8][11].

## The timeline

The research involved both field and laboratory experiments, including burying bioplastics in soil for a year [7][12]. The study's results were published in The ISME Journal on September 2, 2026, and simultaneously announced by the University of Konstanz [6][8].

## What changed and for whom

This discovery provides a new foundation for future research into microbial plastic degradation and understanding the spread of antibiotic resistance in the environment [6]. The findings emphasize that a plastic's chemical composition and its disposal environment dictate whether microbes can effectively break it down [7]. Professor David Schleheck advocated for designing polymers with specific biochemical weak points that microbes can target for degradation [1][2]. This approach could lead to more truly biodegradable materials.

## What the subject has said publicly

Harry Lerner explained that the humus layer, where the bioplastic films were buried, is a natural environment for the breakdown of cellulose and other natural polymers [9][12]. Professor David Schleheck highlighted the broader implication of the research, stressing the importance of designing polymers with inherent biochemical weaknesses that microbes can exploit [1][2]. However, the researchers cautioned that while the enzyme can chemically break down penicillin in a laboratory setting, this does not confirm it provides antibiotic resistance to living bacteria in their natural environment; this remains a hypothesis [1][4].

## What we could not confirm

It could not be confirmed whether the "Pac-Man enzyme" provides antibiotic resistance to living bacteria in their natural environment, as this is currently a hypothesis [1][4]. The behavior of the enzyme in open environmental conditions or at an industrial scale also remains unknown [8].

## Evidence cited
1. Scientists discover a plastic-eating "Pac-Man" enzyme with a surprising secret -- ScienceDaily (sciencedaily.com) — https://www.sciencedaily.com/releases/2026/10/261014015509.htm
2. An Enzyme With Potential: New Type of Plastic-Degrading Enzyme Discovered in Bacteria (technologynetworks.com) — https://www.technologynetworks.com/neuroscience/news/an-enzyme-with-potential-new-type-of-plastic-degrading-enzyme-discovered-in-bacteria-379058
3. Microbe enzyme eats bioplastics, resists antibiotics (plasticstoday.com) — https://www.plasticstoday.com/sustainability/microbe-enzyme-eats-bioplastics-resists-antibiotics
4. Pac-Man Enzyme Eats Plastic and Antibiotics (youtube.com) — https://www.youtube.com/watch?v=R2jQx1B0fL4
5. Scientists Discover A Plastic Eating Pac-Man Enzyme With A Surprising Secret: Scientists Discover Pac-Man Enzyme That Eats Plastic And Antibiotics (indiatimes.com) — https://www.indiatimes.com/explainers/news/scientists-discover-pac-man-enzyme-that-eats-plastic-and-antibiotics-615694.html
6. An enzyme with potential: new type of plastic-degrading enzyme discovered in bacteria (uni-konstanz.de) — https://campus.uni-konstanz.de/en/node/2586
7. Pac-Man Enzyme: Bioplastics And Antibiotics Degradation — All You Need To Know (natureworldnews.com) — https://natureworldnews.com/articles/62325/20261021/pac-man-enzyme-biodegradable-plastics-antibiotics.htm
8. A 'Pac-Man' enzyme that degrades bioplastics and antibiotics (netguide.io) — https://www.netguide.io/article/2026/09/10/a-pac-man-enzyme-that-degrades-bioplastics-and-antibiotics/
9. German biologists find 'Pac-Man' enzyme that breaks down bioplastics and antibiotics (thecooldown.com) — https://www.thecooldown.com/green-home/plastic-eating-enzyme-bioplastics-antibiotics-pac-man-university-konstanz/
10. An enzyme with potential: new type of plastic-degrading enzyme discovered in bacteria (the-microbiologist.com) — https://www.the-microbiologist.com/news/an-enzyme-with-potential-new-type-of-plastic-degrading-enzyme-discovered-in-bacteria
11. r/science - Scientists discover a plastic eating “Pac-Man” enzyme with a surprising secret (from pubmed.ncbi.nlm.nih.gov) (reddit.com) — https://www.reddit.com/r/science/comments/1ds2p26/scientists_discover_a_plastic_eating_pacman/
12. An enzyme that offers hope: Novel plastic-degrading enzyme discovered in bacteria (bionity.com) — https://www.bionity.com/en/news/1189734/an-enzyme-that-offers-hope-novel-plastic-degrading-enzyme-discovered-in-bacteria.html
13. Biologists Discover Bacterial Enzyme That Breaks Down Plastic & Antibiotics | Biology (sci.news) — https://www.sci.news/biology/pac-man-enzyme-12242.html
14. Scientists Discover a Plastic-Eating “Pac-Man” Enzyme With a Surprising Secret (scitechdaily.com) — https://scitechdaily.com/scientists-discover-a-plastic-eating-pac-man-enzyme-with-a-surprising-secret/
15. Bacterial family-VIII esterase displays dual activities: hydrolysis of polyester bioplastics and β-lactam antibiotics (academic.oup.com) — https://academic.oup.com/ismej/article/doi/10.1093/ismejo/wrag203/8778421
16. Facebook - The Mary Robinson Centre (facebook.com) — https://www.facebook.com/maryrobinsoncentre/posts/pfbid025175J7iF1g6c7w3Lp9ZqM74VjP4uX58r7g2G4D5f9A9Sj1Y4YgT3H2T1D2M7l/
17. An enzyme with potential: new type of plastic-degrading enzyme discovered in bacteria (uni-konstanz.de) — https://www.uni-konstanz.de/en/university/news-and-media/current-announcements/press-releases/2026/an-enzyme-with-potential-new-type-of-plastic-degrading-enzyme-discovered-in-bacteria/