With foam at the mouth: flour worms can digest polystyrene

Chinese biologists from Peking University of Aviation and Cosmonautics have discovered that flour worms are able to process such a common form of plastic as polystyrene. In the absence of more delicious food, the larvae eat the polystyrene and process about 48% of its mass into carbon dioxide.

Scientists have long been looking for application to the huge natural diversity of microorganisms. Some modify bacteria to produce fuel . Others are looking for ways to process plastic that does not degrade in vivo for hundreds of years that could solve the problem of processing it in a natural way.

Not so long ago, biologists found a mushroom in the Amazon jungle that can feed on polyurethane . Now, Chinese scientists have found thatflour beetle larvae (its full name is the large flour hrushchak), or flour worms, in the absence of alternatives, can eat polystyrene.

Although they prefer, of course, normal food. “When we gave the worms another meal, like potatoes, they ate it first,” said Yang Jun, one of the authors of the study .

The researchers enclosed 40 larvae and 6 grams of polystyrene in glass flasks for two weeks, and measured the level of CO ₂ in them . It turned out that during this time, the larvae ate about a quarter of the foam. Of the eaten mass, almost 48% was converted to carbon dioxide, 49% was isolated. The rest of the mass was converted into energy and body mass of the larvae.

A study of their secretions showed that the foam degraded during digestion. Recycling such an unusual meal took less than 24 hours for the worms. At the same time, the larvae felt no worse than relatives who ate normal food, and successfully lived a month.

By feeding the worms with antibiotics, scientists found that the foam stopped digesting, and therefore, bacteria living inside the flour worms are responsible for its processing. Having isolated 13 cultures of bacteria from worms, scientists tried to grow them on top-dressing from polystyrene foam, and they achieved the best success with Exiguobacterium bacteria belonging to firmikut .

So far, the industrial use of flour worms is still far away. It is necessary to investigate whether undigested foam fragments will be toxic to the environment. Scientists also plan to more fully understand the mechanism of assimilation of polystyrene and the genes included in this process.