Silk-inspired ‘plantymers’ as a biodegradable plastic

Universiteit van Amsterdam

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Demonstration of the coacervate-based zein film for food preservation. The appearance of bananas with and without the packaging was recorded over 5 days.

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Credit: Wang et al.

What if we could make plastic from plants? A team of researchers from the Netherlands and China introduces ‘plantymers’, plastics that are sustainably produced from plant proteins and that break down naturally in the environment. This invention tackles the two main drawbacks of traditional plastics.

Few materials can compete with plastics. They are remarkably versatile, cheap, water-repellent, light and durable. As a result, plastics are used everywhere: from packaging to healthcare, construction, textiles, furniture and electronics.

Unfortunately, traditional plastics are derived from crude oil and are not biodegradable. Their production and end-of-life incineration contribute to climate change. Plastic also forms a persistent pollutant that has a devastating impact on wildlife, and microplastics accumulate up the food chain with unclear health effects for humans. Plastic pollution is recognised as an important problem by the European Environment Agency and the United Nations Environment Programme.

Enter plantymers, made from plant proteins that are spun or sheared into fibres or sheets. The production of plantymers is similar to how spiders produce silk fibres. Because plantymers are composed of natural proteins, they are biodegradable. This stands in contrast to traditional plastics which are composed of intertwined non-biodegradable hydrocarbon chains.

“We show that the fibers and films that we make via this method are strong enough to compete with fossil-based plastics, and are immediately useful for – for example – fruit packaging,” says Xiufeng Li from Nanjing Agricultural University, who led the research team.

Li worked closely with Yijie Wang from Jiangnan University, a visiting researcher at Wageningen University & Research (WUR), and Wang’s supervisors in the Netherlands, Renko de Vries (WUR) and Joshua Dijksman from the University of Amsterdam.

How to make a plantymer

In principle, plantymers can be made from different plant proteins. For this first demonstration, the research team used the corn protein zein. In its pure form, zein is clear, odourless, tasteless, water-insoluble and edible, and it already has a variety of industrial and food uses.

The key to making a plantymer is finding the right way to dissolve the proteins and prepare them for being made into a fibre or film. Zein doesn’t dissolve in water, so the research team first dissolved it in a solution of 80% ethanol. Once the protein was dissolved, they added extra water to the mixture until the solution was only around 47% ethanol.

Because the zein remains water-repellent, it forms protein-rich droplets within the liquid. This protein-rich liquid is called the ‘coacervate phase’, and it can be separated from the water-rich solvent. The coacervate liquids can then be spun or sheared into a plastic-like fibre of film.

The same process is used in nature: Spiders use a similar protein-rich liquid to spin their famously strong silk. Dijksman notes: “The fibre-spinning process is amazingly easy: just let a small amount of solution drip from a nozzle. The dripping creates a flowing thread that immediately dries and becomes a fibre. And to make a film, we simply have to scrape the liquid over a surface.”

The team is now exploring what other proteins from food and agricultural side streams could be used to make plantymers. This concept of turning waste into value is also beginning to be commercialised, marked by the collaboration with a startup enterprise, Upgrade Biopolymers. The mission? To expand the use of this sustainable plastic alternative and help society shift towards a circular economy.

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Journal

Nature Communications

DOI

10.1038/s41467-026-72645-9 

 

Herbivore species dynamics is key to grassland food web stability

Researchers investigate factors that drive ecosystem stability at multiple, rather than a single, level of the food chain.

Yokohama National University

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The horizontal bars indicate the standardized effect, direct (solid) or indirect (transparent), of different variables in a model grassland ecosystem. Our study demonstrates that herbivores, the intermediate consumer trophic level between predators and plants, are a key source of buffering in grassland food webs, underscoring the importance of herbivore dynamics for stabilizing ecosystems. CWM PCoA2 assesses how the average physical, physiological or behavioral characteristics of an entire species community respond to environmental changes or gradients.

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Credit: YOKOHAMA National University

Ecologists have long understood that biodiversity is paramount to the stability of ecosystems. Until now, however, the majority of ecological research has focused on a single layer of ecological life at a time—for example, plant or animal communities.

In reality, ecological systems have multiple layers that interact continuously. Plants are eaten by herbivores, herbivores are eaten by predators, and the fluctuations at one trophic level, or an organism's specific position in the food chain, can ripple through the entire ecosystem.

To address this knowledge gap, a team of researchers from YOKOHAMA National University, the Chinese Academy of Sciences, Tokyo City University and Inner Mongolia University used three years of cumulative data and structural equation models to assess how species diversity, composition, timing of species dominance, and species stability within plant, herbivore and predator communities were associated with ecosystem stability at various levels of the food chain.

The team published their paper on July 18 in the Journal of Animal Ecology.

“The key question we wanted to answer was … simple but largely unresolved: what actually stabilizes a whole food web through time? We asked whether the mechanisms known to stabilize plant communities also scale up to a more complex, multitrophic system, including plants, herbivores and predators. In particular, we wanted to know whether stability across the food web is driven mainly by plants, by predators or by the [herbivores] that link them,” said Takehiro Sasaki, professor in the Faculty of Environment and Information Sciences at YOKOHAMA National University and primary author of the research study.

The team assessed the stability of a natural grassland in Inner Mongolia at three distinct trophic levels—plants, herbivores and predators—to determine their roles in maintaining the stability at their single community level and of the food chain overall.

The researchers use two complementary approaches to assess the stability of the entire ecosystem: an averaging approach and the multiple-threshold approach. The averaging approach assesses the mean stability across different trophic levels in the food web, but may not reveal differences in stability distribution within trophic groups. Because of this, trophic levels may have similar averages when all trophic levels demonstrate moderate stability or when some trophic levels are markedly stable whereas others are significantly unstable. In contrast, the multiple-threshold approach assesses the extent to which stability persists across all trophic levels.

Overall, the research team found that asynchronous species fluctuations within each trophic group played a central role in stabilizing trophic communities and that multitrophic grassland food webs can be stabilized by herbivore species.

“In our study, the strongest and most consistent predictor of multitrophic stability was not plant species dynamics nor predator species dynamics. It was the fact that different herbivore species fluctuated at different times. When one herbivore species declined, another could increase, creating compensatory dynamics within the herbivore community,” said Sasaki.

The researchers explained that differential responses of herbivore species to environmental change, or their asynchrony over time, is important because herbivores sit at the intermediate trophic level of the food web. They mediate how many and what types of plants are consumed and how consistently resources are supplied to predators. In this way, herbivores act as a biological buffer between plant and predator communities. The study showed that herbivores do not function solely as consumers that destabilize plant communities. Instead, they also function as key stabilizers of biodiversity in the food web.

The current study describes the dynamics between plants, herbivores and predators in a semi-arid grassland, but the team looks forward to investigating the effects of herbivore asynchrony on food web stability in other grasslands, forests, agricultural landscapes and under stronger climate variability. Longer monitoring will also help the researchers determine when herbivore communities buffer ecosystem fluctuations and when that buffering capacity breaks down.

“Our ultimate goal is to move biodiversity science beyond simply asking whether biodiversity matters. We want to identify which parts of biodiversity matter most, where they matter and through what mechanisms they sustain ecosystem functioning. If we can understand the biological architecture of stability, we can better predict which ecosystems are most vulnerable—and which components of biodiversity should be conserved to keep ecosystems functioning in a changing world,” said Sasaki.

Taiki Tachibana, Issei Nishimura, Daichi Makishima, Kousuke Tachibana, Xi Sun, and Yuki Iwachido from the Graduate School of Environment and Information Sciences at YOKOHAMA National University in Kanagawa, Japan; Xiaoming Lu, Xuezhen Zhao and Yongfei Bai from the State Key Laboratory of Vegetation and Environmental Change, in the Institute of Botany at the Chinese Academy of Sciences in Beijing, China; Kei Uchida from the Faculty of Environmental Studies at Tokyo City University in Yokohama, Japan; and Wenhuai Li from the Ministry of Education Key Laboratory of Ecology and Resource Use of the Mongolian Plateau & Inner Mongolia Key Laboratory of Grassland Ecology & Observation and the Research Station for the Typical Steppe Ecosystem of the Ministry of Education in the School of Ecology and Environment at Inner Mongolia University in Hohhot, China also contributed to this research.

This work was supported by the Asahi Glass Foundation, the Sumitomo Foundation (2432037), a Grant-in-Aid for Young Scientists A (no. 25712036), a Grant-in-Aid for Scientific Research B (grant no. 22H03791, 24K03127, 25K03306, and 26K03130) from the Ministry of Education, Culture, Sports, Science and Technology of Japan, a grant from the Joint Research Program of Arid Land Research Center, Tottori University (grant no. 06B2005), and a grant from the National Natural Science Foundation of China (31320103916).

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YOKOHAMA National University (YNU) is a leading research university dedicated to academic excellence and global collaboration. Its faculties and research institutes lead efforts in pioneering new academic fields, advancing research in artificial intelligence, robotics, quantum information, semiconductor innovation, energy, biotechnology, ecosystems, and smart city development. Through interdisciplinary research and international partnerships, YNU drives innovation and contributes to global societal advancement.

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Journal

Journal of Animal Ecology

DOI

10.1111/1365-2656.70318 

Method of Research

Experimental study

Article Title

Herbivore species asynchrony underpins multitrophic stability across plants, herbivores and predators

Article Publication Date

18-Jul-2026

 

Many countries overusing powerful antibiotics

Global study produces first estimates of national levels of antibiotics needed to treat infection burden and guide policy

City St George’s, University of London

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Many countries are using too many powerful and inappropriate antibiotics, fuelling antibiotic resistance concerns, while millions lack access to the specific drugs they need. That is according to a major international study of antibiotic use published today in The Lancet Public Health.

Research led by City St George's, University of London and University of Oxford developed the first global framework that estimates how many and which type of antibiotics each country needs to treat their infections.

Antibiotics are grouped by the World Health Organization (WHO) into three categories, known as the "AWaRe" system:

• ‘Access’ antibiotics are used for most common infections and have a lower resistance risk.
• ‘Watch’ antibiotics have a broader spectrum, are used for specific infections and come with higher safety and resistance concerns.
• ‘Reserve’ antibiotics are last resort antibiotics used to treat multi-drug resistant infections.

In 2024, world leaders at the United Nations agreed that at least 70% of antibiotic use worldwide should come from the Access group by 2030. However, no method previously existed to determine the right balance of antibiotics for any individual country.

To address this, researchers analysed global data from 186 countries, territories and areas (CTAs), representing 99.8% of the global population. They grouped these countries into ‘peer groups’ based on similar infection burdens, resistance patterns, socioeconomic characteristics and healthcare access.

Within each group, countries with the lowest antibiotic use and the fewest infection-related deaths were used as benchmarks to determine what optimal antibiotic use should look like for similar countries. They then estimated optimal levels of Access, Watch and Reserve antibiotics required in each setting based on infection and resistance burdens.

The team calculated that in 2019, around 43 billion days of antibiotics were needed globally, averaging out to roughly one antibiotic course per person per year, to treat all bacterial infections appropriately. They found that 77% of global antibiotic use should be Access antibiotics, suggesting the UN's 70% target is reasonable.

Although higher-income countries currently use the most Watch and Reserve antibiotics, the study estimates that more than 80% of the world's optimal need for these medicines lies in lower-income countries, where infectious disease and antimicrobial resistance burdens are highest.

The researchers then compared their estimates with real-world antibiotic use data from 67 countries where this data was available. Nearly three-quarters (72%) of countries analysed were using more antibiotics in total than needed, and almost every country (99%) prescribed too many Watch antibiotics, which contribute the most to antibiotic resistance. Worryingly, 60% of countries were still using antibiotics that the WHO considers should no longer be prescribed.

At the same time, 42% of countries were using fewer Access antibiotics than estimated optimal levels, and more than half (52%) were not using enough Reserve antibiotics than estimated to be needed. This means patients with life-threatening drug-resistant infections might not be receiving the specific treatments they need.

The findings suggest that many countries could improve antibiotic use by reducing unnecessary Watch antibiotic prescribing while increasing access to essential Access antibiotics, and ensuring availability of Reserve antibiotics for patients with highly resistant infections.

Aislinn Cook, lead author and Senior Research Fellow in Infectious Diseases Epidemiology at City St George's, University of London, and DPhil student at Nuffield Department of Primary Care Health Sciences, University of Oxford said:

“Our findings show the world faces a double challenge - while some antibiotics are being overused, millions of people may still lack access to the medicines they need to treat their infections.

“We have developed the first practical way for countries to estimate how much of each type of antibiotic their populations need based on infection burden and antibiotic resistance. This framework can help move the conversation beyond measuring antibiotic consumption to matching antibiotic use with public health need. This can support countries to develop more targeted policies to reduce overuse while ensuring sustainable access to effective antibiotics.”

The team emphasise that improving access to antibiotics for the most vulnerable populations will require action at both local and national levels. This includes ensuring that quality-assured antibiotics are available and affordable in frontline healthcare settings, while national governments ensure that the right antibiotics are procured and supplied in sufficient quantities. The researchers also highlight the need for better monitoring of antibiotic use to identify areas of overuse and underuse, and for national targets based on local data that align antibiotic use more closely with public health and clinical need.

Dr Koen Pouwels, Associate Professor in Health Economics, Nuffield Department of Primary Care Health Sciences, University of Oxford and co-author, said:

“Global targets such as aiming for 70% of antibiotic use to come from the WHO Access group are an important starting point, but they cannot tell countries how much of each AWaRe antibiotic group they actually need.

“By providing country-specific benchmarks, our work gives policymakers a practical way to move beyond percentage targets and make better-informed decisions about reducing overuse, improving access and strengthening antibiotic stewardship. Importantly, these benchmarks can become more ambitious over time if countries reduce infection burden, even in the face of demographic change."

The study was funded by the Wellcome Trust.

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Journal

The Lancet Public Health

Subject of Research

People

Article Title

Estimating optimal levels of WHO Access, Watch, Reserve (AWaRe) antibiotic use in 186 countries, territories, and areas on the basis of clinical infection and resistance burden

Article Publication Date

21-Jul-2026

 

Leukemia: Social inequalities shape childhood mortality in Brazil

Ludwig-Maximilians-Universität München

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An international study involving LMU found regional differences in childhood lymphoid leukemia mortality across Brazil.

Why do children with lymphoid leukemia face markedly different mortality rates depending on where they live in Brazil? In a collaboration between researchers at LMU and the Federal University of Rio de Janeiro (UFRJ), trends in childhood lymphoid leukemia mortality in Brazil over more than two decades were analyzed, along with the association of regional development and healthcare structures with the observed disparities. The findings have been published in The Lancet Regional Health – Americas.

The study shows that mortality increased particularly in Brazil’s socioeconomically disadvantaged North and Northeast, while rates remained stable or declined in more affluent regions. Improvements in primary health care alone were not sufficient to reduce these disparities. Instead, the researchers highlight the need of targeted, region-specific strategies strengthening specialized pediatric oncology services and improving access to timely diagnosis and treatment to address subnational inequities in childhood cancer outcomes.

“Our findings show that health inequalities extend far beyond access to healthcare alone. Reducing childhood leukemia mortality requires addressing the underlying social and structural inequalities that continue to affect vulnerable populations,” says doctoral candidate and first author Bárbara Sarni Sanches.

“The strength of our study lies in linking longitudinal leukemia mortality data with complex socioeconomic and healthcare information. Using biostatistical methods, we combined these data into two meaningful indices, used them to model mortality and investigate their association with regional differences in mortality trends,” says Dr. Ursula Berger from LMU’s Institute for Medical Information Processing, Biometry and Epidemiology (IBE).

According to professor Marcelo Gerardin Poirot Land, from the Faculty of Medicine at UFRJ, the findings provide important evidence to support the planning of public policies aimed at reducing health inequalities. In addition, the study highlights the importance of international scientific collaboration and research networks in addressing complex public health challenges. The partnership between UFRJ and LMU brings together expertise in epidemiology, biostatistics, and public health, enabling the application of innovative methodologies to investigate the determinants of childhood leukemia mortality in Brazil.

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Journal

The Lancet

DOI

10.1016/j.lana.2026.101557 

Article Title

Spatiotemporal analysis and socioeconomic determinants of pediatric lymphoid leukemias mortality in Brazil from 2000 to 2021: an ecological study

 

Recycling isn't a distraction, but it won't stop climate change either

University of New South Wales

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In research published today, UNSW Sydney behavioural scientists, in collaboration with researchers from Griffith University, say they found no evidence for claims that climate action at the individual level distracted from wanting meaningful action on climate change.

After following almost 2800 Australians over four years through the National Climate Action Survey, the researchers found people who made environmentally friendly choices – recycling, using reusable cups and containers, taking public transport, adopting greener diets and cycling to work – were not less likely to support broader climate action.

That finding contradicts a long-running criticism that governments and companies encourage small lifestyle changes to deflect attention from the harder work of transforming energy systems and regulating industry.

“Individual climate actions neither facilitate nor undermine broader climate engagement,” says lead author Dr Omid Ghasemi from the UNSW Institute for Climate Risk & Response.

“We found no evidence for the idea that personal action might reduce collective action or policy support because people feel they've done enough, overestimate the impact of individual actions, or feel less worried about climate change,” he says.

Instead, the research suggests everyday environmental behaviours are expressions of existing values rather than catalysts – or obstacles – for broader political engagement.

Not a gateway

Australians who took more personal environmental actions in general tended to be more politically engaged overall – and more likely to sign petitions, attend demonstrations and support climate policies. But tracking those same people between 2021 and 2024 showed that increasing someone's personal climate actions did not, by itself, make them more – or less – politically engaged the following year.

“Our research contradicts the strongest version of the 'recycling is a distraction' argument,” says Professor Ben Newell, Director of the UNSW Institute for Climate Risk & Response.

“But it also offers little support for the idea that small lifestyle changes automatically lead people towards activism or systemic reform.”

Dr Ghasemi says the study doesn't dismiss the concern of governments and companies targeting consumer behaviour to shift their own responsibility away from systemic reform.

“Personal and systemic action are not necessarily rivals,” he says.

Beyond public policy

The researchers also detected a small decline in collective climate action and support for climate policy between 2021 and 2024, although personal environmental behaviours remained relatively stable.

Dr Ghasemi says a possible explanation is cost-of-living pressures.

“When people are under more financial pressure, they may have less time, energy, or willingness to engage in collective action or support policies that are perceived to have economic costs,” he says.

“But whatever the reason, our results suggest that it is not driven by greater engagement in individual climate action.”

The findings also carry implications for businesses investing in sustainability programs.

Encouraging employees or customers to adopt greener behaviours may not undermine support for broader climate action, but neither should those initiatives be treated as substitutes for deeper organisational change.

“Doing more personal climate action doesn’t seem to come at the expense of broader climate engagement,” Dr Ghasemi says.

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Journal

npj Climate Action

DOI

10.1038/s44168-026-00405-y 

Recycling food waste would bring huge benefits, but microplastics a challenge

A first nationwide look shows diversion of U.S. food waste from landfills could reduce related climate impacts by 89% and nutrient pollution by 50%, UVM researchers say

University of Vermont

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Keeping food waste out of landfills provides climate and other environmental benefits, and Vermont requires residents to divert these materials to better management pathways. With other states considering similar policies, UVM researchers studied the potential outcomes of bringing these efforts to a national scale.

The new findings, out today in the journal Nature Food, indicate a need to plan not just for channeling food waste into landfill alternatives—but also for managing the microplastics that can remain in the resulting compost and other organic materials, says study coauthor Eric Roy, professor in the Rubenstein School of Environment and Natural Resources.

Solutions to keep food waste out of landfills include turning it into compost for agricultural use and using anaerobic digestion to produce biogas for renewable energy. While researchers have looked at these disposal options before, none had taken microplastic contamination into consideration at scale, says Roy.

Key findings include that diversion of food waste from landfills to composting and anaerobic digestion at a national scale in the U.S. would reduce the current climate impacts of these wastes by 89 to 99%. Environmental nutrient pollution from food waste management, which can contribute to infamous summer blue-green algae blooms in lakes, could drop by 49 to 54% for nitrogen, and 78 to 98% for phosphorus. But if the organics resulting from composting and anaerobic digestion were spread on agricultural fields, they could also carry around 20,000 tons of microplastics into the soil annually, the researchers found.

“If you don't intentionally intervene and have a plan for how you're going to minimize plastic in your recovered soil amendments, there will probably be plastic there based on just how pervasive it is in our food system right now,” says lead author Kate Porterfield, a Gund Institute for Environment postdoctoral researcher. “It's literally everywhere.”

The work points to the need for better planning at every step of the food recycling process—including the design of packaging before the food’s ever in it, Porterfield says.

Using a combination of data from across the U.S., the team created “life cycle assessment models” to inspect potential effects of nationwide composting, anaerobic digestion, or landfill disposal of food waste. The approach takes into account every step of food waste’s journey, from the moment it arrives at a waste transfer station, to its fate as compost in a field, methane gas converted to electricity, or a slimy pile with plastic, slowly releasing greenhouse gases in a landfill.

The researchers also considered a potential drop in the need for synthetic fertilizers in agriculture resulting from replacement by recovered nutrients in organic wastes—but found that nutrients recovered from food waste would offset only about 2% of annual U.S. demand.

Dealing with food waste is becoming increasingly top-of-mind among some policymakers, with up to 40% of U.S. food wasted, and a quarter of landfills’ already dwindling space taken up by discarded food. Composting food waste has gone from being the domain of avid home gardeners to a legal requirement in some U.S. jurisdictions. Vermont, being an early adopter of required food waste diversion away from landfills, is seeing some of the challenges that can pop up alongside the benefits, says Roy. Additional efforts to increase composting and anaerobic digestion of food waste currently exist as a national patchwork, with tremendous variability from place to place.

Roy, who also directs UVM’s Casella Center for Circular Economy and Sustainability, says he’s not aware of any upcoming national food waste diversion plan. Casella Center research focuses on finding greener pathways for waste management. With more states and municipalities considering food waste recycling, studies like this one can both clarify benefits and reveal potential issues in advance, Roy says, helping to ease the transition. Upfront planning to reduce microplastic contamination in food waste at the outset is needed to maximize the net environmental benefits of food waste diversion programs and policies.

“We thought, we need to think about this at a big scale because Vermont's leading on this issue,” Roy says. “What if more states jump on board?”

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Journal

Nature Food

DOI

10.1038/s43016-026-01396-z 

Method of Research

Computational simulation/modeling

Article Title

Food waste recycling in the USA can reduce climate and nutrient pollution impacts yet risks plastic accumulation in soils

Article Publication Date

23-Jul-2026