Among many efforts to recycle plastic waste polluting air, land, and oceans is one that converts such waste into useful chemicals.

A team led by Gregg Beckham, a chemical engineer at the United States National Renewable Energy Laboratory in Golden, Colorado, developed this process, Nature reported.

Beckham's team used a cobalt or manganese-based catalyst to break down high-density polyethylene that make up food packaging, polystyrene which includes styrofoam, and polyethylene terephthalate found in drinking bottles. The plastic waste turns into oxygen-containing organic-acid molecules such as dicarboxylic acids, terephthalic acid, and benzoic acid.

The team, whose experiment was published in the journal Science, then used an engineered bacterium, Pseudomonas putida, that would eat the said acids, thereby producing biopolymers or plastics that can be made into biodegradable plastic bottles, cups and wrappers.

It's amazing that some microorganisms are capable of breaking down plastics. Humans can only go as far as unknowingly ingesting such non-biodegradable materials, microplastics, for example, with bad effects to their health. So it was not surprising that a family complained when they found a small piece of cellophane on their meals when they recently dined at the Namji restaurant in Milton Keynes, Buckinghamshire, United Kingdom.

When the diners' £170 bill arrived, the mother called the waiter and showed the piece of plastic on her plate. The restaurant manager tried to appease the customers by offering them a 20-percent discount on the four starters, seven side dishes, four drinks, and six main courses they ordered and ate, according to UK News Yahoo!

The woman's husband refused to pay the tab and they stormed out of the restaurant.

The restaurant owner, Naseem Khan, said it was all a ruse by the customers to avoid paying for their meals. Khan said the diners were complaining about their food from the start but they finished all the meals anyway.

Khan also reviewed the CCTV footage of the diners and confirmed they were a victim of an "eat-and-run" modus as the plastic was planted. In the video, the woman was shown "tearing the wrapper off a cigarette packet she'd stored in her underwear and placing it in her bowl of chicken curry," UK News Yahoo! reported.

Khan, who feeds homeless people, said she would have given the family free meals if they couldn't afford them. She reported the incident to the Thames Valley Police which called on the public to volunteer information about the deceptive diners.