Plastic-Eating Bacteria Enzyme Enhanced

Plastic pollution is one of the most persistent environmental challenges of the modern era, with billions of tons of waste clogging landfills and oceans. While mechanical recycling has existed for decades, it is often inefficient and degrades the quality of the material. However, a major breakthrough in biotechnology offers a new solution. Scientists have engineered a “super-enzyme” derived from bacteria that can devour plastic waste in a matter of days rather than centuries.

The Evolution of the Super-Enzyme

The journey to this biological breakthrough began in 2016 when researchers in Japan discovered a bacterium called Ideonella sakaiensis 201-F6 outside a bottle recycling plant. This bacteria had naturally evolved to eat polyethylene terephthalate (PET), the strong plastic used in soda bottles and food containers. It produced two specific enzymes to digest the material: PETase and MHETase.

While the natural bacteria worked, it was slow. It took weeks to degrade a thin film of plastic. This prompted a global race to enhance nature’s design.

Combining Forces: The Chimeric Enzyme

A team led by Professor John McGeehan at the University of Portsmouth in the UK, alongside researchers from the US Department of Energy’s National Renewable Energy Laboratory (NREL), took the research a step further.

In 2018, they accidentally engineered a version of the PETase enzyme that was 20% faster than the natural evolution. By 2020, they achieved a massive leap forward. The team physically linked the two enzymes (PETase and MHETase) together to create a “chimeric” super-enzyme. This engineered hybrid works up to six times faster than the natural enzyme alone.

Here is how the two components work together:

  • PETase: This attacks the hard, crystalline surface of the plastic first.
  • MHETase: This chops up the liberated smaller chunks, speeding up the entire digestion process.

FAST-PETase: The AI-Driven Breakthrough

The enhancement of these enzymes did not stop with the Portsmouth team. In 2022, researchers at the University of Texas at Austin utilized artificial intelligence to engineer an even more robust variant.

Led by Hal Alper, the team used machine learning to generate thousands of mutations of the PETase enzyme to find a version that could survive different environmental conditions. They called the result FAST-PETase (functional, active, stable, and tolerant PETase).

The results of FAST-PETase were staggering:

  • Speed: It can break down plastic in as little as 24 hours.
  • Temperature Tolerance: Unlike other enzymes that require high heat to function, FAST-PETase works effectively at temperatures below 50 degrees Celsius (122 degrees Fahrenheit).
  • Restoration: It breaks the plastic down into its original monomers (basic chemical building blocks), allowing the material to be rebuilt into brand-new, clear plastic bottles.

Why "Chemical Recycling" is Different

To understand the value of this super-enzyme, you have to look at the flaws in traditional recycling. When you toss a blue soda bottle into a recycling bin, it is usually chopped up and melted. This process, called thermomechanical recycling, weakens the plastic.

Because the resulting plastic is weaker, it cannot usually be made into a new soda bottle. Instead, it is “down-cycled” into carpets, fleece jackets, or park benches. Once those products wear out, they end up in a landfill.

The enzyme method offers true circular recycling:

  1. Depolymerization: The enzyme acts like molecular scissors. It cuts the chemical bonds of the PET plastic.
  2. Recovery: The process recovers the original raw materials (terephthalic acid and ethylene glycol).
  3. Remaking: Manufacturers can use these raw materials to create virgin-quality plastic over and over again.

Commercial Viability and Future Scale

The transition from a laboratory beaker to an industrial plant is already underway. A French company called Carbios is currently one of the leaders in bringing enzymatic recycling to the market.

Carbios has developed its own enhanced enzyme and has partnered with major consumer goods giants including L’Oréal, Nestlé Waters, PepsiCo, and Suntory Beverage & Food Europe. In 2021, they successfully produced the first food-grade PET bottles made entirely from enzymatically recycled plastic.

Carbios is currently constructing the world’s first industrial-scale enzymatic recycling plant in Longlaville, France. They aim to have the facility operational by 2025, with the capacity to process 50,000 tons of post-consumer PET waste annually. This creates a tangible path toward a market where plastic is treated as a valuable raw material rather than disposable trash.

Frequently Asked Questions

Is this enzyme safe for the environment?

Yes. The enzymes are proteins that are non-toxic and biodegradable. They specifically target PET plastic and do not attack other materials. Once their job is done or they are deactivated, they degrade naturally just like any other organic protein.

Can these enzymes break down all types of plastic?

Currently, these specific enzymes (PETase and MHETase) are optimized for PET (polyethylene terephthalate). This is the plastic commonly used for water bottles, soft drink containers, and clothing fibers (polyester). Research is ongoing to find or engineer enzymes that can tackle other plastics like polyethylene (PE) or polypropylene (PP), but PET is the current focus.

Will this technology eliminate plastic pollution?

It is a major tool, but not a magic wand. These enzymes excel at recycling waste that is collected and processed in facilities. They are not currently designed to be sprayed into the ocean to eat floating trash, as the enzymes require specific conditions to work efficiently. The primary goal is to stop the production of new virgin plastic by making recycling infinitely sustainable.