Microbial hitchhikers on microplastics: The exchange of aquatic microbes across distinct aquatic habitats.

Microplastics (MPs) have the potential to modify aquatic microbial communities and distribute microorganisms, including pathogens. This poses a potential risk to aquatic life and human health. Despite this, the fate of 'hitchhiking' microbes on MPs that traverse different aquatic habitats remains largely unknown. To address this, we conducted a 50-day microcosm experiment, manipulating estuarine conditions to study the exchange of bacteria and microeukaryotes between river, sea and plastisphere using a long-read metabarcoding approach. Our findings revealed a significant increase in bacteria on the plastisphere, including Pseudomonas, Sphingomonas, Hyphomonas, Brevundimonas, Aquabacterium and Thalassolituus, all of which are known for their pollutant degradation capabilities, specifically polycyclic aromatic hydrocarbons. We also observed a strong association of plastic-degrading fungi (i.e., Cladosporium and Plectosphaerella) and early-diverging fungi (Cryptomycota, also known as Rozellomycota) with the plastisphere. Sea MPs were primarily colonised by fungi (70%), with a small proportion of river-transported microbes (1%-4%). The mere presence of MPs in seawater increased the relative abundance of planktonic fungi from 2% to 25%, suggesting significant exchanges between planktonic and plastisphere communities. Using microbial source tracking, we discovered that MPs only dispersed 3.5% and 5.5% of river bacterial and microeukaryotic communities into the sea, respectively. Hence, although MPs select and facilitate the dispersal of ecologically significant microorganisms, drastic compositional changes across distinct aquatic habitats are unlikely.

Microplastic pollution in the Chapora River, Goa, Southwest India: spatial distribution and risk assessment.

The amount of information available on the microplastic (MP) contamination in Goa's riverine water systems is currently limited. The abundance, size, colour, and polymer composition of microplastics in Chapora River surface water were investigated in this study. MPs in Chapora River surface water ranged from 0.1 particles/L (station 13) to 0.47 particles/L (station 5). The mean (± standard deviation) MP concentration was 0.25 (± 0.13) particles/L. Fibre was the dominant shape (77.15%), followed by fragments (12.36%), films (9.36%), and foam (1.12%). Most MPs were found in the 0.1-0.3 mm size range, then in the 0.3-1 mm and 1-5 mm. The dominant type of polymer studied was polyethylene terephthalate (PET; 46%), followed by high-density polyethylene (HDPE; 14%), polypropylene (PP; 5%), and polystyrene (PS; 1%). The risk assessment study indicated high risk with respect to PHI, while PLI shows low risk in the area. The source of MPs was mostly anthropogenic in nature in the region. When compared with other tropical rivers, MP pollution was relatively lower in the Chapora River. Nevertheless, the baseline data will help the local administration take mitigation measures to reduce the impact of MP pollution in the region.

Assessing microbial plastic degradation requires robust methods.

Plastics are versatile materials that have the potential to propel humanity towards circularity and ultimate societal sustainability. However, the escalating concern surrounding plastic pollution has garnered significant attention, leading to widespread negative perceptions of these materials. Here, we question the role microbes may play in plastic pollution bioremediation by (i) defining polymer biodegradability (i.e., recalcitrant, hydrolysable and biodegradable polymers) and (ii) reviewing best practices for evaluating microbial biodegradation of plastics. We establish recommendations to facilitate the implementation of rigorous methodologies in future studies on plastic biodegradation, aiming to push this field towards the use of isotopic labelling to confirm plastic biodegradation and further determine the molecular mechanisms involved.

Joint toxicity of cadmium (II) and microplastic leachates on wheat seed germination and seedling growth.

Cadmium (Cd) pollution ranks first in soils (7.0%) and microplastics usually have a significant adsorption capacity for it, which could pose potential threats to agricultural production and human health. However, the joint toxicity of Cd and microplastics on crop growth remains largely unknown. In this study, the toxic effects of Cd2+ and two kinds of microplastic leachates, polyvinyl chloride (PVC) and low-density polyethylene (LDPE), on wheat seed germination and seedlings' growth were explored under single and combined conditions. The results showed that Cd2+ solution and two kinds of microplastic leachates stimulated the wheat seed germination process but inhibited the germination rate by 0-8.6%. The combined treatments promoted wheat seed germination but inhibited the seedlings' growth to different degrees. Specifically, the combination of 2.0 mg L-1 Cd2+ and 1.0 mgC L-1 PVC promoted both seed germination and seedlings' growth, but they synergistically increased the antioxidant enzyme activity of seedlings. The toxicity of the PVC leachate to wheat seedlings was stronger than LDPE leachate. The addition of Cd2+ could alleviate the toxicity of PVC leachate on seedlings, and reduce the toxicity of LDPE leachate on seedlings under the same concentration class combinations but aggravated stress under different concentration classes, consistent with the effect on seedlings' growth. Overall, Cd2+, PVC, and LDPE leachates have toxic effects on wheat growth, whether treated under single or combined treatments. This study has important implications for the joint toxicity of Cd2+ solution and microplastic leachates in agriculture.

The aging behavior of degradable plastic polylactic acid under the interaction of environmental factors.

Microplastics leaching from aging biodegradable plastics pose potential environmental threats. This study used response surface methodology (RSM) to investigate the impact of temperature, light, and humidity on the aging characteristics of polylactic acid (PLA). Key evaluation metrics included the C/O ratio, functional groups, crystallinity, surface topography, and mechanical properties. Humidity was discovered to have the greatest effect on the ageing of PLA, followed by light and temperature. The interactions between temperature and light, as well as humidity and sunlight, significantly impact the aging of PLA. XPS analysis revealed PLA underwent aging due to the cleavage of the ester bond (O-C=O), resulting in the addition of C=O and C-O. The aging process of PLA was characterized by alterations in surface morphology and augmentation in crystallinity, resulting in a decline in both tensile strength and elongation. These findings might offer insights into the aging behavior of degradable plastics under diverse environmental conditions.

Impact of Micro- and Nano-Plastics on Human Intestinal Organoid-Derived Epithelium.

The development of patient-derived intestinal organoids represents an invaluable model for simulating the native human intestinal epithelium. These stem cell-rich cultures outperform commonly used cell lines like Caco-2 and HT29-MTX in reflecting the cellular diversity of the native intestinal epithelium after differentiation. In our recent study examining the effects of polystyrene (PS), microplastics (MPs), and nanoplastics (NPs), widespread pollutants in our environment and food chain, on the human intestinal epithelium, these organoids have been instrumental in elucidating the absorption mechanisms and potential biological impacts of plastic particles. Building on previously established protocols in human intestinal organoid culture, we herein detail a streamlined protocol for the cultivation, differentiation, and generation of organoid-derived monolayers. This protocol is tailored to generate monolayers incorporating microfold cells (M cells), key for intestinal particle uptake but often absent in current in vitro models. We provide validated protocols for the characterization of MPs/NPs via scanning electron microscopy (SEM) for detailed imaging and their introduction to intestinal epithelial monolayer cells via confocal immunostaining. Additionally, protocols to test the impacts of MP/NP exposure on the functions of the intestinal barrier using transendothelial electrical resistance (TEER) measurements and assessing inflammatory responses using cytokine profiling are detailed. Overall, our protocols enable the generation of human intestinal organoid monolayers, complete with the option of including or excluding M cells, offering crucial techniques for observing particle uptake and identifying inflammatory responses in intestinal epithelial cells to advance our knowledge of the potential effects of plastic pollution on human gut health. These approaches are also amendable to the study of other gut-related chemical and biological exposures and physiological responses due to the robust nature of the systems. © 2024 Wiley Periodicals LLC. Basic Protocol 1: Human intestinal organoid culture and generation of monolayers with and without M cells Support Protocol 1: Culture of L-WRN and production of WRN-conditioned medium Support Protocol 2: Neuronal cell culture and integration into intestinal epithelium Support Protocol 3: Immune cell culture and integration into intestinal epithelium Basic Protocol 2: Scanning electron microscopy: sample preparation and imaging Basic Protocol 3: Immunostaining and confocal imaging of MP/NP uptake in organoid-derived monolayers Basic Protocol 4: Assessment of intestinal barrier function via TEER measurements Basic Protocol 5: Cytokine profiling using ELISA post-MP/NP exposure.

Plastics and the Sustainable Development Goals: From waste to wealth with microbial recycling and upcycling.

Plastics pollution has become one of the greatest concerns of the 21st century. To date, around 10 billion tons of plastics have been produced almost exclusively from non-renewable sources, and of these, <10% have been recycled. The majority of discarded plastic waste (>70%) is accumulating in landfills or the environment, causing severe impacts to natural ecosystems and human health. Considering how plastics are present in every aspect of our daily lives, it is evident that a transition towards a Circular Economy of plastics is essential to achieve several of the Sustainable Development Goals. In this editorial, we highlight how microbial biotechnology can contribute to this shift, with a special focus on the biological recycling of conventional plastics and the upcycling of plastic-waste feedstocks into new value-added products. Although important hurdles will need to be overcome in this endeavour, recent success stories highlight how interdisciplinary approaches can bring us closer to a bio-based economy for the sustainable management of plastics.

Microorganism-mediated biodegradation for effective management and/or removal of micro-plastics from the environment: a comprehensive review.

Micro- plastics (MPs) pose significant global threats, requiring an environment-friendly mode of decomposition. Microbial-mediated biodegradation and biodeterioration of micro-plastics (MPs) have been widely known for their cost-effectiveness, and environment-friendly techniques for removing MPs. MPs resistance to various biocidal microbes has also been reported by various studies. The biocidal resistance degree of biodegradability and/or microbiological susceptibility of MPs can be determined by defacement, structural deformation, erosion, degree of plasticizer degradation, metabolization, and/or solubilization of MPs. The degradation of microplastics involves microbial organisms like bacteria, mold, yeast, algae, and associated enzymes. Analytical and microbiological techniques monitor microplastic biodegradation, but no microbial organism can eliminate microplastics. MPs can pose environmental risks to aquatic and human life. Micro-plastic biodegradation involves fragmentation, assimilation, and mineralization, influenced by abiotic and biotic factors. Environmental factors and pre-treatment agents can naturally degrade large polymers or induce bio-fragmentation, which may impact their efficiency. A clear understanding of MPs pollution and the microbial degradation process is crucial for mitigating its effects. The study aimed to identify deteriogenic microorganism species that contribute to the biodegradation of micro-plastics (MPs). This knowledge is crucial for designing novel biodeterioration and biodegradation formulations, both lab-scale and industrial, that exhibit MPs-cidal actions, potentially predicting MPs-free aquatic and atmospheric environments. The study emphasizes the urgent need for global cooperation, research advancements, and public involvement to reduce micro-plastic contamination through policy proposals and improved waste management practices.

Investigation of waste characteristics and recycling behaviour at educational institutes.

In this study, the waste generation at the educational institutes chosen from four different levels (kindergartens, primary, secondary and high schools) in Istanbul was measured on-site and the contents of the waste thrown into the recycling bins were determined to specify capture rates. Separation and weighing processes were performed at 16 spots in high schools, 12 spots in secondary schools, 7 spots in primary schools and 7 spots in kindergartens. A survey was conducted to determine the students' awareness of recycling in these schools. It was revealed that the wastes produced from educational institutes are organics (36.4 %), paper (24 %), plastics (14.4 %), glass (8.1 %), metals (4.8 %) and miscellaneous (12.3 %). The survey results indicate that 93 % of the participants think recycling is important, 71 % of them throw their waste into suitable waste bins and 59 % of them know the location of the recycling bins. At the primary school level, a very high rate of paper waste (92.3 %) was reported in plastic bins while plastic waste collected in these bins remained only 5.7 %. It was also seen that glass waste captured in glass bins and metal waste in metal bins remain very low rates (20.9 % and 29.2 %, respectively) at the secondary school level. At the high school level, it was determined that the most commonly captured wastes in glass, plastics and paper bins are glass (47.5 %), plastic (43.2 %) and paper (32.5 %), respectively. Correlation analyses indicated a high positive correlation (p < 0.05) between particular types of waste.

Biofilm enhances the interactive effects of microplastics and oxytetracycline on zebrafish intestine.

The enhanced adsorption of pollutants on biofilm-developed microplastics has been proved in many studies, but the ecotoxicological effects of biofilm-developed microplastics on organisms are still unclear. In this study, adult zebrafish were exposed to original microplastics, biofilm-developed microplastics, original microplastics absorbed with oxytetracycline (OTC), and biofilm-developed microplastics absorbed with OTC for 30 days. The intestinal histological damage, intestinal biomarker response, gut microbiome and antibiotic resistance genes (ARGs) profile of zebrafish were measured to explore the roles of biofilm in the effects of microplastics. The results showed that biofilm-developed microplastics significantly increased the number of goblet cells in intestinal epithelium compared with the control group. The biofilm-developed microplastics also induced the oxidative response in the zebrafish intestines, and biofilm changed the response mode in the combined treatment with OTC. Additionally, the biofilm-developed microplastics caused intestinal microbiome dysbiosis, and induced the abundance of some pathogenic genera increasing by several times compared with the control group and the original microplastics treatments, regardless of OTC adsorption. Furthermore, the abundance of ARGs in biofilm-developed microplastics increased significantly compared with the control and the original microplastic treatments. This study emphasized the significant influence and unique role of biofilm in microplastic studies.

Anthropogenic particle concentrations and fluxes in an urban river are temporally variable and impacted by storm events.

Anthropogenic particles (AP), which include microplastics and other synthetic, semisynthetic, and anthropogenically modified materials, are pollutants of concern in aquatic ecosystems worldwide. Rivers are important conduits and retention sites for AP, and time series data on the movement of these particles in lotic ecosystems are needed to assess the role of rivers in the global AP cycle. Much research assessing AP pollution extrapolates stream loads based on single time point measurements, but lotic ecosystems are highly variable over time (e.g., seasonality and storm events). The accuracy of models describing AP dynamics in rivers is constrained by the limited studies that examine how frequent changes in discharge drive particle retention and transport. This study addressed this knowledge gap by using automated, high-resolution sampling to track AP concentrations and fluxes during multiple storm events in an urban river (Milwaukee River) and comparing these measurements to commonly monitored water quality metrics. AP concentrations and fluxes varied significantly across four storm events, highlighting the temporal variability of AP dynamics. When data from the sampling periods were pooled, there were increases in particle concentration and flux during the early phases of the storms, suggesting that floods may flush AP into the river and/or resuspend particles from the benthic zone. AP flux was closely linked to river discharge, suggesting large loads of AP are delivered downstream during storms. Unexpectedly, AP concentrations were not correlated with other simultaneously measured water quality metrics, including total suspended solids, fecal coliforms, chloride, nitrate, and sulfate, indicating that these metrics cannot be used to estimate AP. These data will contribute to more accurate models of particle dynamics in rivers and global plastic export to oceans. PRACTITIONER POINTS: Anthropogenic particle (AP) concentrations and fluxes in an urban river varied across four storm events. AP concentrations and fluxes were the highest during the early phases of the storms. Storms increased AP transport downstream compared with baseflow. AP concentrations did not correlate with other water quality metrics during storms.

Hydroxylase-like Biomimetic Nanozyme Synthesized via a Urea-Mediated MOF Pyrolytic Reconstruction Strategy for Non-"o-Phenol hydroxyl"-Dependent Dopamine Electrochemical Sensing.

Dopamine (DA), an essential neurotransmitter, is closely associated with various neurological disorders, whose real-time dynamic monitoring is significant for evaluating the physiological activities of neurons. Electrochemical sensing methods are commonly used to determine DA, but they mostly rely on the redox reaction of its o-phenolic hydroxyl group, which makes it difficult to distinguish it from substances with this group. Here, we design a biomimetic nanozyme inspired by the coordination structure of the copper-based active site of dopamine ß-hydroxylase, which was successfully synthesized via a urea-mediated MOF pyrolysis reconstruction strategy. Experimental studies and theoretical calculations revealed that the nanozyme with Cu-N3 coordination could hydroxylate the carbon atom of the DA ß-site at a suitable potential and that the active sites of this Cu-N3 structure have the lowest binding energy for the DA ß-site. With this property, the new oxidation peak achieves the specific detection of DA rather than the traditional electrochemical signal of o-phenol hydroxyl redox, which would effectively differentiate it from neurotransmitters, such as norepinephrine and epinephrine. The sensor exhibited good monitoring capability in DA concentrations from 0.05 to 16.7 µM, and its limit of detection was 0.03 µM. Finally, the sensor enables the monitoring of DA released from living cells and can be used to quantitatively analyze the effect of polystyrene microplastics on the amount of DA released. The research provides a method for highly specific monitoring of DA and technical support for initial screening for neurocytotoxicity of pollutants.

Molecular-Weight-Dependent Degradation of Plastics: Deciphering Host-Microbiome Synergy Biodegradation of High-Purity Polypropylene Microplastics by Mealworms.

The biodegradation of polypropylene (PP), a highly persistent nonhydrolyzable polymer, by Tenebrio molitor has been confirmed using commercial PP microplastics (MPs) (Mn 26.59 and Mw 187.12 kDa). This confirmation was based on the reduction of the PP mass, change in molecular weight (MW), and a positive Δδ13C in the residual PP. A MW-dependent biodegradation mechanism was investigated using five high-purity PP MPs, classified into low (0.83 and 6.20 kDa), medium (50.40 and 108.0 kDa), and high (575.0 kDa) MW categories to access the impact of MW on the depolymerization pattern and associated gene expression of gut bacteria and the larval host. The larvae can depolymerize/biodegrade PP polymers with high MW although the consumption rate and weight losses increased, and survival rates declined with increasing PP MW. This pattern is similar to observations with polystyrene (PS) and polyethylene (PE), i.e., both Mn and Mw decreased after being fed low MW PP, while Mn and/or Mw increased after high MW PP was fed. The gut microbiota exhibited specific bacteria associations, such as Kluyvera sp. and Pediococcus sp. for high MW PP degradation, Acinetobacter sp. for medium MW PP, and Bacillus sp. alongside three other bacteria for low MW PP metabolism. In the host transcriptome, digestive enzymes and plastic degradation-related bacterial enzymes were up-regulated after feeding on PP depending on different MWs. The T. molitor host exhibited both defensive function and degradation capability during the biodegradation of plastics, with high MW PP showing a relatively negative impact on the larvae.

Exposure to microplastics renders immunity of the thick-shell mussel more vulnerable to diarrhetic shellfish toxin-producing harmful algae.

Despite both microplastics (MPs) and harmful algae blooms (HABs) may pose a severe threat to the immunity of marine bivalves, the toxification mechanism underlying is far from being fully understood. In addition, owing to the prevalence and sudden occurrence characteristics of MPs and HABs, respectively, bivalves with MP-exposure experience may face acute challenge of harmful algae under realistic scenarios. However, little is known about the impacts and underlying mechanisms of MP-exposure experience on the susceptibility of immunity to HABs in bivalve mollusks. Taking polystyrene MPs and diarrhetic shellfish toxin-producing Prorocentrum lima as representatives, the impacts of MP-exposure on immunity vulnerability to HABs were investigated in the thick-shell mussel, Mytilus coruscus. Our results revealed evident immunotoxicity of MPs and P. lima to the mussel, as evidenced by significantly impaired total count, phagocytic activity, and cell viability of haemocytes, which may result from the induction of oxidative stress, aggravation of haemocyte apoptosis, and shortage in cellular energy supply. Moreover, marked disruptions of immunity, antioxidant system, apoptosis regulation, and metabolism upon MPs and P. lima exposure were illustrated by gene expression and comparative metabolomic analyses. Furthermore, the mussels that experienced MP-exposure were shown to be more vulnerable to P. lima, indicated by greater degree of deleterious effects on abovementioned parameters detected. In general, our findings emphasize the threat of MPs and HABs to bivalve species, which deserves close attention and more investigation.

A review of microplastics in wastewater treatment plants in Türkiye: Characteristics, removal efficiency, mitigation strategies for microplastic pollution and future perspective.

The effluent of WWTPs is an important source of microplastics (MP) for the aquatic environment. In this review study, MPs in wastewater treatment plants (WWTP) in Türkiye and their removal from WWTPs are reviewed for the first time. First, MP characteristics in the influent and effluent of WWTPs in Türkiye are discussed. In the next section, the abundance of MPs in the influent and effluent of WWTPs in Türkiye and the MP removal efficiency of WWTPs in Türkiye are evaluated. Then, the results of studies on MP abundance and characteristics in Türkiye's aquatic environments are presented and suggestions are made to reduce MPs released from WWTPs into the receiving environments. Strategies for reducing MPs released to the receiving environment from WWTPs of Türkiye are summarized. In the last section, research gaps regarding MPs in WWTPs in Türkiye are identified and suggestions are made for future studies. This review paper provides a comprehensive assessment of the abundance, dominant characteristics, and removal of MPs in WWTPs in Türkiye, as well as the current status and deficiencies in Türkiye. Therefore, this review can serve as a scientific guide to improve the MP removal efficiency of WWTPs in Türkiye.

Interactive effects between water temperature, microparticle compositions, and fiber types on the marine keystone species Americamysis bahia.

Recently, there has been an increasing emphasis on examining the ecotoxicological effects of anthropogenic microparticles (MPs), especially microplastic particles, and related issues. Nevertheless, a notable deficiency exists in our understanding of the consequences on marine organisms, specifically in relation to microfibers and the combined influence of MPs and temperature. In this investigation, mysid shrimp (Americamysis bahia), an important species and prey item in estuarine and marine food webs, were subjected to four separate experimental trials involving fibers (cotton, nylon, polyester, hemp; 3 particles/ml; approximately 200 µm in length) or fragments (low-density Polyethylene: LDPE, polylactic acid: PLA, and their leachates; 5, 50, 200, 500 particles/ml; 1-20 µm). To consider the effects in the context of climate change, three different temperatures (22, 25, and 28 °C) were examined. Organismal growth and swimming behavior were measured following exposure to fragments and microfibers, and reactive oxygen species and particle uptake were investigated after microfiber exposure. To simulate the physical characteristics of MP exposure, such as microfibers obstructing the gills, we also assessed the post-fiber-exposure swimming behavior in an oxygen-depleted environment. Data revealed negligible fragment, but fiber exposure effects on growth. PLA leachate triggered higher activity at 25 °C and 28 °C; LDPE exposures led to decreased activity at 28 °C. Cotton exposures led to fewer behavioral differences compared to controls than other fiber types. The exposure to hemp fibers resulted in significant ROS increases at 28 °C. Microfibers were predominantly located within the gastric and upper gastrointestinal tract, suggesting extended periods of residence and the potential for obstructive phenomena over the longer term. The combination of increasing water temperatures, microplastic influx, and oxidative stress has the potential to pose risks to all components of marine and aquatic food webs.

Trapping of microplastics and other anthropogenic particles in seagrass beds: Ubiquity across a vertical and horizontal sampling gradient.

Seagrass beds can trap large amounts of marine debris leading to areas of accumulation, known as 'sinks', of anthropogenic particles. While the presence of vegetation can enhance accumulation, less is known about how the trapping effect changes from vegetated to less vegetated patches. To test this, vegetation and sediment were sampled along a vegetation percent cover gradient from the centre of seagrass beds to nearby less vegetated patches. To determine whether trapped particles can lead to increased accumulation in associated fauna, gastropods were also collected from the transects laid across this gradient. Extracted anthropogenic particles were counted and characterised. Particles were detected in all sample types and reached quantifiable limits in at least 50% of sediment and gastropod samples. There was no significant difference in the distribution of particles found in seagrass beds compared to less vegetated patches, suggesting other factors contribute to the trapping efficiency of biogenic habitats besides simply the presence or absence of vegetation.

Micro- and nanoplastics concepts for particle and fibre toxicologists.

Micro- and nanoplastic particles (MNP) are omnipresent as either pollution or intentionally used in consumer products, released from packaging or even food. There is an exponential increase in the production of plastics. With the realization of bioaccumulation in humans, toxicity research is quickly expanding. There is a rapid increase in the number of papers published on the potential implications of exposure to MNP which necessitates a call for quality criteria to be applied when doing the research. At present, most papers on MNP describe the effects of commercially available polymer (mostly polystyrene) beads that are typically not the MNP of greatest concern. This is not a fault of the research community, necessarily, as the MNPs to which humans are exposed are usually not available in the quantities needed for toxicological research and innovations are needed to supply environmentally-relevant MNP models. In addition, like we have learned from decades of research with particulate matter and engineered nanomaterials, sample physicochemical characteristics and preparation can have major impacts on the biological responses and interpretation of the research findings. Lastly, MNP dosimetry may pose challenges as (1) we are seeing early evidence that plastics are already in the human body at quite high levels that may be difficult to achieve in acute in vitro studies and (2) plastics are already in the diets fed to preclinical models. This commentary highlights the pitfalls and recommendations for particle and fibre toxicologists that should be considered when performing and disseminating the research.

Can bioplastics always offer a truly sustainable alternative to fossil-based plastics?

Bioplastics, comprised of bio-based and/or biodegradable polymers, have the potential to play a crucial role in the transition towards a sustainable circular economy. The use of biodegradable polymers not only leads to reduced greenhouse gas emissions but also might address the problem of plastic waste persisting in the environment, especially when removal is challenging. Nevertheless, biodegradable plastics should not be considered as substitutes for proper waste management practices, given that their biodegradability strongly depends on environmental conditions. Among the challenges hindering the sustainable implementation of bioplastics in the market, the development of effective downstream recycling routes is imperative, given the increasing production volumes of these materials. Here, we discuss about the most advisable end-of-life scenarios for bioplastics. Various recycling strategies, including mechanical, chemical or biological (both enzymatic and microbial) approaches, should be considered. Employing enzymes as biocatalysts emerges as a more selective and environmentally friendly alternative to chemical recycling, allowing the production of new bioplastics and added value and high-quality products. Other pending concerns for industrial implementation of bioplastics include misinformation among end users, the lack of a standardised bioplastic labelling, unclear life cycle assessment guidelines and the need for higher financial investments. Although further research and development efforts are essential to foster the sustainable and widespread application of bioplastics, significant strides have already been made in this direction.