The Unseen Heroes Tackling Plastic Pollution: Plastivores

Every year, humanity generates approximately 400 million tons of plastic, a staggering 80% of which ends up as trash. A mere tenth of this waste is recycled, while 60% is either incinerated or buried in landfills. The remaining 30% finds its way into the environment, causing pollution that can persist for centuries. But, there's hope on the horizon: the rise of plastivores.

The Plastic Problem: A Brief Overview

Plastics, composed of long, repeating chains called polymers, are created from oil, gas, and coal through processes involving high temperatures and pressures. These man-made polymers differ significantly from naturally occurring ones. Since their introduction in the 1950s, most microbes haven't evolved the necessary enzymes to break them down. The robust chemical bonds in plastics require temperatures comparable to their creation for degradation, conditions that are lethal to most microbes.

The Accumulation of Waste

The result is an accumulation of plastic waste, with common plastics like Polyethylene, Polypropylene, and Polyester-terephthalate persisting for decades. An estimated 10 million tons of plastic waste enter the ocean annually, primarily as microplastic fragments that contaminate the food chain.

The Promise of Plastivores: Microbes to the Rescue

Fortunately, nature may offer a solution in the form of microbes capable of breaking down plastics. In 2016, researchers in Japan discovered Ideonella sakaiensis 201-F6, a bacterium with two enzymes that can slowly degrade PET polymers at relatively low temperatures.

Super-Enzymes and High-Temperature Degradation

Scientists have since isolated and improved these enzymes, creating "super-enzymes" that can break down PET up to six times faster. Additionally, researchers have identified Leaf Branch Compost Cutinases, powerful degrading enzymes found in high-temperature environments like compost piles. These enzymes can degrade PET plastic at temperatures reaching 70˚C, weakening the polymers and making them digestible.

The Future of Plastic Recycling: A Multi-Faceted Approach

While these discoveries offer promise for PET recycling, it's important to remember that PET is just one type of plastic. Effective methods for biologically degrading other plastics, such as PEs and PPs, which require temperatures above 130˚C to break down, are still needed.

A Call for Innovation and Responsibility

Currently, researchers are exploring extreme environments for more heat-tolerant plastivores and engineering better plastivorous enzymes in the lab. However, relying solely on these tiny helpers is not enough. We must:

• Rethink our relationship with plastics.
• Make better use of existing plastics.
• Stop producing more of the same.
• Design more environmentally friendly polymers that plastivores can easily break down.

The challenge of plastic pollution requires a comprehensive approach, combining innovative biological solutions with responsible production and consumption practices. By embracing this multi-faceted strategy, we can pave the way for a cleaner, more sustainable future.