The perfect plastic? Plant-based, fully saltwater degradable, zero microplastics
video:
This bag of tomatoes is made from the new plant-based plastic that uses FDA-approved ingredients. Watch as the bag completely dissolves in artificial seawater after just a few hours, without leaving any microplastics.
view moreCredit: RIKEN
Researchers led by Takuzo Aida at the RIKEN Center for Emergent Matter Science (CEMS) in Japan have one-upped themselves in their quest to solve our microplastic problem. In a recent study published in the Journal of the American Chemical Society they report a new type of plastic made from plant cellulose, the world’s most abundant organic compound. The new plastic is strong, flexible, and capable of rapid decomposition in natural environments, setting it apart from other plastics marketed as biodegradable.
Microplastics are a global contaminant found in nearly every ecosystem, from the soil and the ocean to the animals and plants that live there. They have even been found in human tissue and the bloodstream where they likely have adverse effects. While biodegradable plastics and even some cellulose-derived plastics (cellulose nitrate or cellulose acetate) are not new, most plastics labeled “biodegradable” do not degrade in marine environments or they take a very long time to degrade, leaving microplastics behind in the meantime.
Last year, Aida and his team developed a plastic that could quickly degrade in salt water within several hours, without leaving any microplastics behind. That plastic was a supramolecular plastic made from two polymers held together by reversible interactions called "salt bridges." In the presence of salt water, the bonds holding the two polymers together came apart and the plastic decomposed. But this plastic wasn’t as practical as it could be for real-world manufacture.
The new plant-based plastic is similar, except that one of the two polymers is a commercially available, FDA approved, biodegradable wood-pulp derivative called carboxymethyl cellulose. Finding a compatible second polymer took some trial and error, but eventually the team found a safe crosslinking agent made from positively charged polyethylene-imine guanidinium ions. When the cellulose and guanidinium ions were mixed in room temperature water, the negatively and positively charged molecules attracted each other like magnets and formed the critical cross-linked network that makes this kind of plastic strong. At the same time, the salt bridges holding the network together broke as expected in the presence of salt water. To avoid unintentional decomposition, the plastic can be protected with a thin coating on the surface.
So far so good. But even though the new plastic decomposed quickly, it initially suffered from being too brittle because of the cellulose. The resulting plastic was colorless, transparent, and extremely hard, but had a fragile glass-like quality. What the team needed was a good plasticizer, some small molecule they could add to the mix to make the plastic more flexible, yet remain hard. After much experimenting, they discovered that the organic salt choline chloride worked wonders. By adding varying amounts of this FDA-approved food additive to the plastic, the researchers were able to fine-tune exactly how flexible they wanted the plastic to be. Depending on the amount of choline chloride, the plastic can range from being hard and glass-like to being so elastic that it can be stretched up to 130% of its original length. It can even be made into a strong yet thin film with a thickness of only 0.07 mm. A video of a bag made from the new plant-based biodegradable plastic can be seen decomposing here: https://youtu.be/glBYYhk1STQ.
The improvements on the original design are not trivial. “While our initial study focused mostly on the conceptual,” explains Aida, “this study shows that our work is now at a more practical stage.” The new carboxymethyl cellulose supramolecular plastic, dubbed CMCSP, is as strong as conventional petroleum-based plastics and its mechanical properties can be adjusted as needed, without spoiling the intrinsic transparency, processability, seawater dissociability, or close-loop recyclability. By using common and inexpensive FDA-approved biodegradable ingredients, Aida and his team have ensured that their plastic will be able to move quickly to real-world, practical applications.
“Nature produces about one trillion tons of cellulose every year,” says Aida. “From this abundant natural substance, we have created a flexible yet tough plastic material that safely decomposes in the ocean. This technology will help protect the Earth from plastic pollution.”
Schematic showing how cellulose and polyethylene-imine guanidinium combine in water to form the initial glassy and transparent cellulose-based plastic film. Subsequently, researchers discovered how to adjust its mechanical properties using the organic salt choline chloride.
This plastic bag containing tomatoes is made from the new plant-based biodegradable plastic. Its ingredients are common, affordable, and FDA-approved. It's made simply by mixing them in water. Within 2 hours is can decompose completely in artificial seawater, without leaving any microplastics behind. See the video here: https://youtu.be/glBYYhk1STQ
Credit
RIKENJournal
Journal of the American Chemical Society
Rising heat reshapes how microbes break down microplastics, new review finds
Biochar Editorial Office, Shenyang Agricultural University
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Impacts of high temperatures on microbial degradation of microplastics and strategies for optimization
view moreCredit: Zheng Yuan, Rongxin Lv, Fredrick Gudda, Ahmed Mosa, Patryk Oleszczuk, Tatiana Minkina, Yanzheng Gao & Lei Tang
As microplastics accumulate in soils, waters, and even the human body, scientists are racing to understand how these persistent pollutants can be safely removed from the environment. A new review published in New Contaminants highlights a critical but often overlooked factor in this challenge: temperature.
The study examines how high and extreme temperatures influence the ability of microorganisms to degrade microplastics. Drawing on evidence from laboratory studies, natural hot environments, and industrial systems, the authors show that heat can both accelerate and suppress microbial breakdown of plastic particles, depending on conditions and the organisms involved.
Microplastics are plastic fragments smaller than five millimeters that originate from the breakdown of larger plastic items or are manufactured directly for industrial use. Once released, they can persist for decades to centuries, entering food chains and posing risks to ecosystems and human health.
Microbial degradation has emerged as a promising, environmentally friendly approach for addressing microplastic pollution. Certain bacteria, fungi, and algae can attach to plastic surfaces and secrete enzymes that break long polymer chains into smaller molecules, eventually converting them into carbon dioxide, water, and biomass. However, the efficiency of this process depends strongly on temperature.
“Temperature acts like a double edged sword for microbial degradation of microplastics,” said corresponding author Lei Tang of Nanjing Agricultural University. “Moderate warming can make plastics easier for microbes to attack, but extreme heat can also damage microbial cells and deactivate key enzymes.”
According to the review, elevated temperatures can soften plastics and reduce their crystallinity, increasing the mobility of polymer chains and making them more accessible to microbial enzymes. In some cases, heating plastics to near their glass transition temperature significantly boosts degradation rates.
At the same time, extreme heat can overwhelm many common microorganisms. Enzymes may denature, cell membranes can lose integrity, and entire microbial communities may collapse. As global warming increases the frequency and intensity of heat waves, these opposing effects are becoming increasingly relevant in natural and engineered environments.
The authors point to thermophilic microorganisms, which thrive at high temperatures, as a potential solution. These heat loving microbes are found in hot springs, composting systems, and geothermal soils, and some have already demonstrated the ability to degrade plastics such as polyethylene, polyethylene terephthalate, and polylactic acid at temperatures above 50 degrees Celsius.
“Thermophiles produce enzymes that remain stable and active at temperatures that would disable ordinary microbes,” Tang explained. “These organisms represent an underexplored resource for plastic biodegradation under warming conditions.”
Beyond natural thermophiles, the review highlights advances in enzyme engineering, genetic modification, and synthetic microbial consortia. By redesigning enzymes or constructing microbial communities with complementary functions, researchers are beginning to build systems that maintain high degradation efficiency even under extreme thermal stress.
However, the authors caution that significant challenges remain. High costs, slow degradation rates, limited effectiveness for certain plastic types, and potential ecological risks associated with releasing engineered microbes all need careful consideration.
“Microbial solutions are not a silver bullet,” said Tang. “But by understanding how temperature controls both plastics and microbes, we can design smarter and safer strategies for reducing microplastic pollution.”
The review concludes that integrating thermophilic microbes, engineered enzymes, and optimized environmental conditions could play a key role in future microplastic remediation efforts, especially in a warming world.
As climate change reshapes ecosystems worldwide, understanding how heat affects the natural cleanup power of microbes may be essential for managing one of the planet’s most persistent pollutants.
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Journal reference: Yuan Z, Lv R, Gudda F, Mosa A, Oleszczuk P, et al. 2025. Impacts of high temperatures on microbial degradation of microplastics and strategies for optimization. New Contaminants 1: e018
https://www.maxapress.com/article/doi/10.48130/newcontam-0025-0019
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About the Journal:
New Contaminants is an open-access journal focusing on research related to emerging pollutants and their remediation.
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Method of Research
Literature review
Subject of Research
Not applicable
Article Title
Impacts of high temperatures on microbial degradation of microplastics and strategies for optimization
Article Publication Date
11-Dec-2025
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