We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Microbial decomposition of biodegradable plastics on the deep-sea floor
AI summary Read the abstract
Researchers demonstrated that microbes on the deep-sea floor can decompose certain biodegradable plastics, even at depths greater than 5,000 meters and near-freezing temperatures. However, not all biodegradable plastics broke down equally, with PLA (a common biodegradable plastic) showing no degradation at any site. This means that while some biodegradable alternatives do break down in the deep ocean, others persist just like conventional plastics.
Microbes can decompose biodegradable plastics on land, rivers and seashore. However, it is unclear whether deep-sea microbes can degrade biodegradable plastics in the extreme environmental conditions of the seafloor. Here, we report microbial decomposition of representative biodegradable plastics (polyhydroxyalkanoates, biodegradable polyesters, and polysaccharide esters) at diverse deep-sea floor locations ranging in depth from 757 to 5552 m. The degradation of samples was evaluated in terms of weight loss, reduction in material thickness, and surface morphological changes. Poly(L-lactic acid) did not degrade at either shore or deep-sea sites, while other biodegradable polyesters, polyhydroxyalkanoates, and polysaccharide esters were degraded. The rate of degradation slowed with water depth. We analysed the plastic-associated microbial communities by 16S rRNA gene amplicon sequencing and metagenomics. Several dominant microorganisms carried genes potentially encoding plastic-degrading enzymes such as polyhydroxyalkanoate depolymerases and cutinases/polyesterases. Analysis of available metagenomic datasets indicated that these microorganisms are present in other deep-sea locations. Our results confirm that biodegradable plastics can be degraded by the action of microorganisms on the deep-sea floor, although with much less efficiency than in coastal settings.
More Papers Like This
Polymer material biodegradation in the deep sea. A review
AI summary Read the abstract
This review examines polymer biodegradation in deep-sea environments, noting that while significant research has focused on coastal marine biodegradation, the deep sea is likely a major sink for ocean plastics and remains understudied. The author finds that deep-sea conditions are generally not conducive to biodegradation but identifies mechanisms from organic fall studies that parallel those in shallow waters, calling for expanded research in this environment.
Degradation of polylactide microplastics in the marine environment under low temperature and in fine-grained sediments - a laboratory scale evaluation
AI summary Read the abstract
Researchers tested whether polylactide (PLA), a plant-based plastic marketed as compostable, actually breaks down in cold marine environments, finding it barely degraded in cold seawater and not at all in oxygen-deprived deep sediments — meaning improperly discarded PLA can persist in the ocean and contribute to nanoplastic pollution just like conventional plastics.
Diversity and distribution of potential polyethylene terephthalate and polypropylene plastic-degrading bacteria communities in deep-sea cold-seep ecosystems
AI summary Read the abstract
Researchers tested bacteria from deep-sea cold-seep sites, places with natural methane and oil-like compounds, to see if they could break down common plastics (PET and PP). After months of lab growth using plastic as the only food source, certain bacterial groups increased in number and visible grooves appeared on the plastic surfaces, suggesting these microbes may help degrade plastic.
Degradation of plastics and plastic-degrading bacteria in cold marine habitats
AI summary Read the abstract
Researchers reviewed how bacteria in cold marine environments — including polar oceans — can break down synthetic plastics, highlighting the unique advantages of cold-adapted microbes for plastic remediation. While plastic degradation in cold habitats is still poorly understood, these microorganisms represent a promising avenue for cleaning up ocean plastic pollution.
Enzyme-embedded polyesters for accelerated biodegradation in the deep sea.
AI summary Read the abstract
Researchers embedded enzymes into compostable plastics and tested them in coastal seawater and deep-sea locations down to 5,503 meters. The enzyme-embedded plastics broke down much faster than regular versions, reaching near-complete degradation at 757 meters within 5 months, while keeping similar strength to plastics without enzymes.
Research digests by email
When a large batch of papers lands in the Atlas, we read through it and send a short write-up of what stood out.