A gutless marine worm revealed an unexpected route through the carbon cycle

Bacteria store carbon and energy in compounds called polyhydroxyalkanoates, or PHAs. Researchers studying a marine worm that depends on bacteria beneath its skin found an enzyme that lets the animal access those stores.

Related enzymes appeared across many animal species, and laboratory tests confirmed activity in examples from distant branches of the animal kingdom. That extends a capability previously associated mainly with microorganisms.

The finding concerns microbial PHAs, not a demonstration that animals can safely consume arbitrary plastic waste. It is interesting both for understanding food webs and for studying biodegradable materials. A substance familiar as an industrial alternative to conventional plastic already has a long ecological history, with more participants in its breakdown than researchers had recognized.