Microbial decomposition of biodegradable plastics on the deep-sea floor.

Researchers found that certain types of biodegradable plastics can be decomposed by microbes on the deep-sea floor, at depths ranging from 757 to 5552 meters. The study focused on various biodegradable materials, including polyhydroxyalkanoates (PHA), biodegradable polyesters, and polysaccharide esters. While poly(L-lactic acid) did not degrade, other materials showed signs of decomposition, although the process was slower at greater depths. Microbial communities associated with the plastics were analyzed, revealing the presence of dominant microorganisms with genes for potential plastic-degrading enzymes (such as PHA depolymerases). The study concludes that biodegradable plastic materials can undergo microbial degradation on the deep-sea floor, albeit less efficiently than in coastal environments.