Microbes in oceans and soils across the globe are evolving to eat plastic, according to a study.

The research scanned more than 200m genes found in DNA samples taken from the environment and found 30,000 different enzymes that could degrade 10 different types of plastic.

The study is the first large-scale global assessment of the plastic-degrading potential of bacteria and found that one in four of the organisms analysed carried a suitable enzyme. The researchers found that the number and type of enzymes they discovered matched the amount and type of plastic pollution in different locations.

But many plastics are currently hard to degrade and recycle. Using enzymes to rapidly break down plastics into their building blocks would enable new products to be made from old ones, cutting the need for virgin plastic production. The new research provides many new enzymes to be investigated and adapted for industrial use.

“We found multiple lines of evidence supporting the fact that the global microbiome’s plastic-degrading potential correlates strongly with measurements of environmental plastic pollution – a significant demonstration of how the environment is responding to the pressures we are placing on it,” said Prof Aleksej Zelezniak, at Chalmers University of Technology in Sweden.

Jan Zrimec, also at Chalmers University, said: “We did not expect to find such a large number of enzymes across so many different microbes and environmental habitats. This is a surprising discovery that really illustrates the scale of the issue.”

As I stated, plastic spring water bottles are a huge source of plastic waste.

Yeah, I toss mine into a basket, take them to the recycling centre every so often. But what happens then?

South Australian technology that uses bacteria and anaerobic digestion to turn contaminated plastics into biogas, fertiliser and compost is undergoing commercial trials.

The process developed by scientist David Thompson and his company Alkane R&D is being scaled up with plans to treat up to 50 tonnes per week in one system.

The units have so far proven successful at breaking down several common household plastics including polyethylene, polypropylene and polystyrene.

Major food processor Thomas Foods International has provided Alkane with access to facilities at its former Murray Bridge meat processing site where Thompson has established a lab to conduct a series of small commercial trials.

Currently, the three-cubic-metre units at the site are capable of processing about 10kg of plastic waste per hour.

“We’ve got three of those in operation and we’ll be getting data off of those over a period of weeks to understand exactly how long it takes to digest plastics at a much larger scale,” Thompson said.

“The bacteria inside the anaerobic digesters is attracted to the waste plastic and convert it into biogas, which is a mixture of methane and carbon dioxide and also liquid digestate, which is a fertiliser and also solid digestate, which is a kind of compost.

“We take plastics that would normally go to landfill or incineration and we pre-treat the plastic and put it through the reactors for the bacteria to digest the plastic and the contaminants.