Before the bags and bottles: the plastic that animals have already learned to eat

A new study by the Max Planck Institute has discovered that dozens of animal species, including marine worms, sponges, and earthworms, are capable of breaking down PHA – a natural plastic produced by bacteria. This ability, found in at least 66 species, has likely existed for hundreds of millions of years and may change our understanding of the carbon cycle in nature.

A new study by the Max Planck Institute for Marine Microbiology in Germany, published in the journal Nature Ecology & Evolution, reveals a surprising ability in the animal kingdom: dozens of animal species can break down PHA – a natural polymer produced by bacteria. The starting point was a unique marine worm called Olavius algarvensis, which lacks a mouth and digestive system and relies on symbiotic bacteria living under its skin. Researchers discovered that one of the bacteria stores PHA, and an enzyme that breaks it down was found in the worm's body. Expanding the search revealed similar enzymes in at least 66 species from nine different groups, including sponges, earthworms, and tiny soil animals. This means the ability is not unique but may be widespread. PHA degrades through natural biological processes, unlike petroleum-based plastics. The findings may change the understanding of the carbon cycle, as animals breaking down PHA could transfer carbon stored in bacteria into the food chain. Researchers estimate that animals have been 'eating' natural plastic for hundreds of millions of years.

Before the bags and bottles: the plastic that animals have already learned to eat