Digging in the wrong place, but digging

Many empty water bottles. Shallow DOF.

The use of enzymes to break down lignin in the quest to produce biofuels has a long history lined with small breakthroughs and a lot of futility. But a new study in Nature describes a mutant enzyme that can reduce plastic bottles to chemical building blocks to make new bottles:

A mutant bacterial enzyme that breaks down plastic bottles for recycling in hours has been created by scientists.

The enzyme, originally discovered in a compost heap of leaves, reduced the bottles to chemical building blocks that were then used to make high-quality new bottles. Existing recycling technologies usually produce plastic only good enough for clothing and carpets.

The company behind the breakthrough, Carbios, said it was aiming for industrial-scale recycling within five years. It has partnered with major companies including Pepsi and L’Oréal to accelerate development. Independent experts called the new enzyme a major advance.

Billions of tonnes of plastic waste have polluted the planet, from the Arctic to the deepest ocean trench, and pose a particular risk to sea life. Campaigners say reducing the use of plastic is key, but the company said the strong, lightweight material was very useful and that true recycling was part of the solution.

The new enzyme was revealed in research published on Wednesday in the journal Nature. The work began with the screening of 100,000 micro-organisms for promising candidates, including the leaf compost bug, which was first discovered in 2012.

“It had been completely forgotten, but it turned out to be the best,” said Prof Alain Marty at the Université de Toulouse, France, the chief science officer at Carbios.

The scientists analysed the enzyme and introduced mutations to improve its ability to break down the PET plastic from which drinks bottles are made. They also made it stable at 72C, close to the perfect temperature for fast degradation.

Bugs doing the heavy lifting has long been an illustrative trope – it is said that life on Earth would grind to halt in days without the constant work of ants. Industrial-scale biological recycling sits on the other end of the teeter-totter with banning all plastics. Only significant inroads into both will help us turn the corner. Promising news. Keep digging.

You and the Food You Rode In On

Over the course of six months living in rural France some years ago, I mysteriously lost about twelve pounds – without trying. Not only was I not trying to lose weight but, being on our second tour in the Vaucluse, Mrs. Green and I were in the throes of all of the delicious meats, vegetables, cheeses, fruits and local Rhone wines that were such an important part of living there. It can’t be overstated, the importance of the food to that place. In fact, besides the inexplicable late afternoon light, there is really not much else going there at all. Which is one reason why it’s a great place to write, among other things. Exercise consisted of mowing the acre out front of the farmhouse twice a month and biking 2 km to the village most every day. Which, when you think about it, is plenty.

But the point is, with all the chipolatas, Camembert, rose’, apricots and creme fraiche, coupled with a largely sedentary lifestyle,  I was baffled about the weight loss until I shared this with a friend upon our return. Without skipping a beat, she pointed out the obvious – that I had largely stopped eating processed food.

All that is to lead-in to this thoughtful post on the same subject, with some sliced media criticism on the side, by Juan Cole. Just go read it. Highly relevant to the current health care debates and everything green you might need to consider. At least on a quiet Sunday.