Environment

Hungry mealworms could keep Styrofoam out of landfills

Hungry mealworms could keep St...
Some of the Stanford mealworms, chowing down on polystyrene
Some of the Stanford mealworms, chowing down on polystyrene
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Some of the Stanford mealworms, chowing down on polystyrene
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Some of the Stanford mealworms, chowing down on polystyrene

If you've ever kept mealworms as food for a pet reptile or frog, then you probably fed them fruits or vegetables. What you likely didn't know, however, was that the insects can also survive quite nicely on a diet of Styrofoam. With that in mind, scientists at Stanford University have now determined that mealworms can break the difficult-to-recycle plastic foam down into a biodegradable waste product.

The Stanford team fed Styrofoam and other forms of polystyrene to a colony of approximately 100 mealworms.

Within 24 hours, the worms consumed 34 to 39 milligrams of the plastic, converting about half of it to carbon dioxide – as they would with any other food source. Bacteria in the worms' gut degraded the other half into tiny biodegradable droppings. The researchers believe that those droppings could safely be used as a crop fertilizer.

The mealworms themselves appeared to be just as healthy as worms that received a more traditional diet of vegetable matter.

Working with colleagues in China, the Stanford team members are now investigating whether mealworms or other insects could also be used to break down additional types of plastic, such as polypropylene. They also hope to find a marine equivalent to mealworms, that could consume the tons of plastic waste currently fouling the world's oceans.

Source: Stanford University

11 comments
SuperFool
wow! very good!
MQ
Do the worms survive for successive generations, or concentrate toxing and eventually suffer from theeir restricted diet.
Will they nourish a frog fed on these worms?
Kuniva
I've ate a few packing peanuts in my time. MD asks a good question though, can the mealworms survive longterm on this without being afflicted by malnourishment, and are they safe to still use as pet food.
jerryd
Or heating it up distilling it into gasoline, diesel would be far better. Plastics to Oil.
Tom Jolly
Saving dumps by turning styrofoam into 50% CO2 and worm droppings seems amazingly stupid. That's like saying, "We're going to burn all the styrofoam to save the dumps". Wouldn't the sequestration of styrofoam in dumps be preferred to polluting the atmosphere? And wouldn't it make a heck of a lot more sense to recycle the styrofoam into something useful?
Grainpaw
My chickens eat any sort of plastic foam that is left in their reach. Egg cartons, pink insulation board, white styrofoam. They don't totally devour something in just an hour, but will steadily work at it over days until I have to pick up small pieces. It doesn't seem to hurt them any, and I still eat the eggs. Chickens followed by mealworms working on the crumbs would be slow death to a pile of styrofoam.
djohnson
Recycle some styrofoam via mealworms, plant a tree to offset that carbon! Seems pretty win-win to me.
the.other.will
Plants can be combined with mealworms for net zero creation of C02. Do chickens digest plastics or just excrete them?
KenKambuel
Lets pretend for a minute that CO2 is beneficial to the greening of the North African Deserts and that the minor amount of CO2 produced by the conversion of Polystyrene is covered by increased plant growth in said desert. Let's also pretend that this greening of the deserts is natures way of compensating for the minute amount of CO2 emitted by man. Where's the down side? Oh btw yet another esteemed paper about Global WTH has been removed due to false data. Oops.
Ralf Biernacki
To clarify a few points:
1. The article says that 50% of the styrofoam was "converted into CO2". This is too much of a shorthand; what actually happened is that the styrofoam was fully metabolized by the mealworms. It was converted into CO2 in the sense that CO2 is the end product of the metabolic chain in all heterotrophs. In other words, once the mealworm dies and decomposes, the CO2 will be released. But that's true of all foodstuffs, not just styrofoam.
2. As far as restrictive diet; the mealworms do not feed on the styrofoam directly. They have a set of gut bacteria that normally feed on cellulose, but evidently can feed on styrofoam as well; the mealworm feeds on these bacteria in a sort of ruminant way. Thus as long as the bacteria thrive, the mealworm will have its normal diet. Obviously, the bacteria will need nutrients other than just pure styrofoam (just carbon and hydrogen), just as they would need more than just pure cellulose (carbon, hydrogen, and oxygen). So yes, in either case some supplementation is necessary. "Vegetable matter" as they put it in the article is more than pure cellulose, and contains these nutrients---phosphorus, nitrates, sulfur, potassium, sodium, calcium, and microelements. The researchers here presumably provided some supplementation as well, although the article fails to mention it.