In a laboratory experiment at the Royal Netherlands Institute for Marine Research, it was proven that the bacterium Rhodococcus ruber eats and digests plastic. Especially for dealing with plastic in the world’s oceans, the bacterium could be part of the solution.

Based on a model study with plastic in artificial seawater in the lab, PhD student Maaike Goudriaan calculated that bacteria can break down about one percent of the fed plastic per year into CO₂ and other harmless substances. “But,” Goudriaan emphasizes, “this is certainly not a solution to the problem of the plastic soup in our oceans. It is, however, another part of the answer to the question of where all the ‘missing plastic’ in the oceans has gone.”

Goudriaan had a special plastic manufactured especially for these experiments with a distinct form of carbon (¹³C) in it. When she fed that plastic to bacteria after pretreatment with “sunlight” – a UV lamp – in a bottle of simulated seawater, she saw that special version of carbon appear as CO₂ above the water. “The treatment with UV light was necessary because we already know that sunlight partially breaks down plastic into bite-sized chunks for bacteria,” the researcher explains.

“This is the first time we have proven in this way that bacteria actually digest plastic into CO₂ and other molecules,” Goudriaan states. It was already known that the bacterium Rhodococcus ruber can form a so-called biofilm on plastic in nature. It had also been measured that plastic disappears under that biofilm. “But now we have really demonstrated that the bacteria actually digest the plastic.”

When Goudriaan calculates the total breakdown of plastic into CO₂, she estimates that the bacteria can break down about one percent of the available plastic per year.

“That’s probably an underestimate. We only measured the amount of carbon-13 in CO₂, so not in the other breakdown products of the plastic. There will certainly be ¹³C in several other molecules, but it’s hard to say what part of that was broken down by the UV light and what part was digested by the bacteria.”
Maaike Goudriaan

Even though marine microbiologist Goudriaan is very excited about the plastic-eating bacteria, she stresses that microbial digestion is not a solution to the huge problem of all the plastic floating on and in our oceans.

“These experiments are mainly a proof of principle. I see it as one piece of the jigsaw, in the issue of where all the plastic that disappears into the oceans stays. If you try to trace all our waste, a lot of plastic is lost. Digestion by bacteria could possibly provide part of the explanation.”

To discover whether ‘wild’ bacteria also eat plastic ‘in the wild’, follow-up research needs to be done. Goudriaan already did some pilot experiments with real sea water and some sediment that she had collected from the Wadden Sea floor.

“The first results of these experiments hints at plastic being degraded, even in nature. A new PhD student will have to continue that work. Ultimately, of course, you hope to calculate how much plastic in the oceans really is degraded by bacteria. But much better than cleaning up, is prevention. And only we humans can do that.”
Maaike Goudriaan

Source: NIOZ

More packaging news

The new flexible films are recyclable and use post-connsumer-recyclates.

Sustainability with flexible packaging films

With their new flexible packaging solutions Hatzopoulos aims to lower carbon emissions and provide customers with sustainable packaging.

Stick packs are being used increasingly by the pharmaceutical industry, for example for liquid medicines for oral ingestion. (Image: Volpak)

FLEXIBLE PACKAGING FOR THE PHARMACEUTICAL SECTOR

Not least, the Covid-19 pandemic has led many people to realise how important medicines that are quickly available and easy to handle can be. Especially if patients are expected to take the medicine without the presence of medical staff, a package with an appropriate design can be helpful.

The carbon neutral paperfloc eco systems keep temperature sensitive products cold and can be disposed of completely with the waste paper. (Image: easy2cool GmbH)

GREEN SHIPPING PACKAGE FOR TEMPERATURE SENSITIVE PRODUCTS

When shipping food and other temperature sensitive products from the life science, cosmetic and pharmaceutical sectors, often polystyrene is used for packaging or individual elements. A start-up from Munich is focussing on a sustainable alternative, which utilises recycled materials for cooling and protection

SEA Vision shows AI-powered software at Interphex

SEA Vision USA is going to attend Interphex tradeshow in New York from April 25 to 27. This edition of Interphex will be particularly felt for SEA Vision Group which, at Booth 2705, will present its AI-powered Automated Line Clearance software for the first time in the US, installed on a machine developed by Marchesini Group.