Plastic is amazing. It keeps my Dr. Pepper in one place and also lent its name to the mean girls in that one movie. Okay and it’s also the material for life-saving products and global supply chains and yada yada yada.

But it has its problems. So many problems in fact that - for the sake of this specific post - we’re only thinking about the problem with recycling plastic. We can save the problems of pollution, floating trash islands, energy required for production, microplastics, and health issues for future fun-time reading. Joy!

So just thinking of the 5-15% of global plastic that even makes it into the recycling bin…

Traditional mechanical recycling (the predominant method) grinds, washes and re‑granulates plastic and then remelts it into new products. It works well for certain plastic types (like soda bottles) but most plastics degrade when repeatedly melted. The material is not as strong or durable as the original, and contamination by additives and other materials is hard to remove. As a result, mechanically recycled plastics are often “down‑cycled” into lower‑value product.

Enzymatic recycling (biorecycling) uses engineered enzymes to cleave plastics into their monomers. According to the U.S. GAO, microbial enzymes degrade plastic into basic chemical components that can be reassembled into “plastics of the same type and quality” rather than down‑cycled material, and this process can also “upcycle” them into high‑value plastics.

But there are also challenges, mostly with scale and production methods. This video is a good high-level overview:

We love a spooky origin story. The PHL7 enzyme at the heart of ESTER Biotech’s technology was discovered in an unusual place: a compost heap at Leipzig’s South Cemetery (Südfriedhof). Researchers explored compost samples in 2022, hoping to find micro‑organisms that could degrade PET plastics. Their search paid off when they extracted a blueprint for a new enzyme they named PHL7.

SPEED: The company reports that PHL7 degraded >90 % of PET plastic within 16 hours and was twice as fast as the prior gold‑standard enzyme LCC. ESTER optimized the enzyme through successive generations: Generation 1 improved performance by 40 %, Generation 2 reduced complete PET disintegration time to 24 hours, and Generation 3 achieved 13–14 hours.

TEMPERATURE: The process operates at ~65 °C under ambient pressure, requiring only moderate heat input (industrial waste heat suffices). It targets amorphous regions of polyesters so that only simple cleaning and size‑reduction are needed before processing.

This means that some of the major obstacles that are preventing enzymatic recycling from reaching scale might not be as insurmountable.

This plastic pot never stood a chance (see video):

The group leading the PHL7 work is ESTER Biotech GmbH, a Leipzig-based biotech startup spun out of Leipzig University. The idea germinated in the university’s Biocity incubator in 2022, and the company was formally started in Feb 2025. They received >€1 million in German federal funding through the EXIST Forschungstransfer programme and €225k validation funding from Saxony’s Development Bank.

ESTER’s vision is to create a bio‑based circular economy for plastics. Its mission is to develop cutting‑edge enzyme technologies that break down plastics into reusable components, reducing reliance on fossil resources and greenhouse‑gas emissions.

Look, this isn’t going to be the first time we talk about plastic. As you saw, it’s a tough topic for us to even segment into one moderately readable post. But the fact of the matter is that society MUST to do something about it.

The incentives are so high we need moonshot thinking. The global plastic packaging market size is nearly $400B, the EU is making stronger regulations, and large beverage companies are working with the myriad of NGOs to solve the pollution problem.

We aren’t nearly qualified to talk scientifically about the unlocks required for enzymatic recycling. But, what makes ESTER Biotech’s work exciting is that the efficiency of PHL7 offers breakthrough thinking into the possibility of scale for enzymatic recycling. When you add in ESTER’s machine learning and high-throughput screening of possible enzymes, we can envision a Moore’s Law for recycling, potentially doubling performance every few years and slashing costs.

So while no one knows the exact path this will all follow, it’s cool to know that hanging out in a graveyard can yield a potential unlock that might mitigate our plastic problem. And then we can spend less time still cutting the plastic six-pack rings before putting them in the bin.

Hell Yeah!

Company presentation: timeline, scaling plans, and funding details

Sterling Plastics: unique analysis about enzymatic recycling and its benefits

Carbios’ enzymatic recycling overview: French company Carbios, another pioneer in enzymatic recycling, has a short explainer video on its site detailing how their enzyme depolymerizes PET and the company’s demonstration plant.

Nature: Plastic recycling: A panacea or environmental pollution problem

Closed Loop Partners: Not an investor in ESTER (as far as we know), but smart group helping to build the “circular economy.”