+27 62 9605168 sales@kmasa.co.za

Nature Eating Plastic

Nature always finds a way: Bug and Bacteria Plastic Eaters

 

There are two species of waxworm that have been identified to successfully eat and digest polyethylene plastics. The Galleria mellonella and Plodia interpunctella. They metabolise polyethylene plastic films into ethylene glycos, a compound which biodegrades rapidly. In the course of 12 hours, in lab conditions, when placed in a polyethylene shopping bag, approximately 100 Galleria mellonella waxworms consumed almost 0.1 gram (0.0032 ounces) of the plastic

This unusual ability to digest matter classically thought of as non-edible may originate with the waxworm’s ability to digest beeswax as a result of gut microbes that are essential in the biodegradation process. This has raised concerns to some environmentalists and biologists because of the possibility of: if we breed waxworms to consume plastic waste, they could in turn effect the bee colonies which is already in trouble.

However, scientists have also found two strains of bacteria, Enterobacter asburiae and Bacillus sp, isolated from the guts of waxworms, to have shown to decompose polyethylene in laboratory testing. In a test with a 28-day incubation period of these two strains of bacteria on polyethylene films, the films’ hydrophobicity decreased. In addition, damage to the films’ surface with pits and cavities was observed using scanning electron microscopy and atomic-force microscopy. Which poses a question: could there be away to isolate the bacteria strands and use them to decompose plastic waste instead of breeding the waxworms itself?

But wait, there is more.

There is also a species of bacteria that can break the molecular bonds of one of the world’s most-used plastics – PET. Tests found the bacteria almost completely degraded low-quality plastic within six weeks.

 The bacteria took longer to eat away highly crystallised PET, which is used in plastic bottles. That means the enzymes and processes would need refinement before they could be useful for industrial recycling or pollution clean-up. Even though this bacteria only eats PET, the discovery could open the door to the discovery or manufacture of biological agents able to break down other plastics.

 

For more information on the bacteria and waxworms check out these great articles:

Could a new plastic-eating bacteria help combat this pollution scourge?

From Buzz, Sting, Bite by Anne Sverdrup-Thygeson

 

 

%d bloggers like this: