‘A huge step forward.’ Mutant enzyme could vastly improve recycling of plastic bottles

Good news! Dedicated to all people afflicted with untreated plastophobia syndrome especially the believers of the environmentalism religion etc.! It is still in its infancy and bit slow, but this is only the beginning!

" ... Polyethylene terephthalate (PET) is one of the world’s most commonly used plastics, with some 70 million tons produced annually. ... In 2012, researchers at Osaka University found one such enzyme in a compost heap. That enzyme, known as leaf-branch compost cutinase (LLC), snips the bonds between PET’s two building blocks: terephthalate and ethylene glycol. ... The researchers then generated hundreds of mutant enzymes changing amino acids at the binding site and adding in heat-stabilizing ones. They then mass produced the mutants in bacteria and screened them to find efficient PET breakers. After repeating this process for several rounds, they isolated a mutant enzyme that’s 10,000 times more efficient at PET bond breaking than the native LLC. It also works without breaking down at 72°C, close to the temperature at which PET becomes molten.
In a small reactor designed to test the enzyme, the team found that it could break down 90% of 200 grams of PET in 10 hours."

‘A huge step forward.’ Mutant enzyme could vastly improve recycling of plastic bottles | Science | AAAS: Advance could prevent one of the world’s most common plastics from ending up in the landfill

"Researchers have engineered an enzyme that effectively breaks down the plastic PET into its constituent monomers. This could allow for more complete recycling of bottles and clothes. Research Article: Tournier et al."

"Here we describe an improved PET hydrolase that ultimately achieves, over 10 hours, a minimum of 90 per cent PET depolymerization into monomers, with a productivity of 16.7 grams of terephthalate per litre per hour (200 grams per kilogram of PET suspension, with an enzyme concentration of 3 milligrams per gram of PET)."

Podcast: A plastic-recycling enzyme, and supercooled molecules

An engineered PET depolymerase to break down and recycle plastic bottles | Nature: Present estimates suggest that of the 359 million tons of plastics produced annually worldwide1, 150–200 million tons accumulate in landfill or in the natural environment2. Poly(ethylene terephthalate) (PET) is the most abundant polyester plastic, with almost 70 million tons manufactured annually worldwide for use in textiles and packaging3. The main recycling process for PET, via thermomechanical means, results in a loss of mechanical properties4. Consequently, de novo synthesis is preferred and PET waste continues to accumulate. With a high ratio of aromatic terephthalate units—which reduce chain mobility—PET is a polyester that is extremely difficult to hydrolyse5. Several PET hydrolase enzymes have been reported, but show limited productivity6,7. Here we describe an improved PET hydrolase that ultimately achieves, over 10 hours, a minimum of 90 per cent PET depolymerization into monomers, with a productivity of 16.7 grams of terephthalate per litre per hour (200 grams per kilogram of PET suspension, with an enzyme concentration of 3 milligrams per gram of PET). This highly efficient, optimized enzyme outperforms all PET hydrolases reported so far, including an enzyme8,9 from th