The geographic distribution of articles published between 2019 and 2024, and focused on the biodegradation of plastic used in agriculture are presented in Figure 2. The data indicate a significant concentration of studies in Asia, particularly in China and India, which together account for 68 studies; these countries with the highest number of research also stand out for their substantial production of plastics. Between May 2021 to May 2024 alone, China produced 6.52 million metric tons of plastic products (Statista, 2024a). Similar is the case with India, which in 2022 produced a volume of 1.7 million metric tons of plastics (Statista, 2024b). Continents such as Oceania and South America present few studies related to the subject, while Oceania presents only one study during the period analyzed. This disparity highlights the low commitment to research on the biodegradation of plastics and underlines the need for a broader commitment to address plastic pollution fully. In Europe, a more balanced distribution of studies is observed, with countries such as Germany, Spain, and the UK contributing notably (Figure 2). This trend may be related to stringent environmental policies and research funding in the European Union, which promotes sustainable solutions for plastic waste management. In Canada, research activity is evident, aligning with its national policies to reduce plastic waste and promote a circular economy (CEPA, 1999). In addition, the map in Figure 2 reveals a growing contribution from developing countries, particularly in Africa and Latin America. In this case, countries such as Brazil and South Africa are beginning to emerge in the field of plastic biodegradation research, possibly driven by the need to manage large amounts of plastic waste and the implementation of stricter environmental policies; they also receive foreign funding as part of biodiversity conservation efforts driven by plastic-producing countries.

The uneven distribution of research also reflects differences in the technological capacity and resources available for research in different regions. While developed countries have access to more funding and advanced technologies (Hsu et al., 2022), developing countries face challenges related to infrastructure and funding, which limits their ability to conduct high-quality research (Orona-Návar et al., 2022). In this context, it is essential to continue fostering international collaboration to share knowledge and strengthen human talent and technologies that can accelerate progress in plastics biodegradation research. Cooperative programs and joint funding can help to balance regional management inequalities and promote global solutions to plastic pollution.

The graph generated in VOSviewer represents a co-occurrence map of terms used in titles and keywords related to the biodegradation of LDPE and other plastics in articles published between 2019 and 2024. The largest and most central nodes, such as “Biodegradation,” “Polyethylene” and “LDPE,” indicate that these terms are the most mentioned and relevant in the analyzed articles. The connections between the nodes reflect the frequency with which these terms appear together in the same studies, suggesting a strong interrelationship between the concepts. Likewise, terms in the green cluster, such as “FTIR,” “GC–MS,” “SEM” and “Fungi,” indicate a focus on analytical techniques and organisms associated with biodegradation. Their prominence is related to methodologies used to assess plastic degradation after various treatments. The blue cluster, which includes terms such as “Microplastics,” “Polypropylene” and “Isolated,” highlights research focused on the degradation of different plastics and microorganisms. The pink group, which contains terms such as “Polystyrene,” “Tenebrio molitor” and “Depolymerization,” reflects an interest in the degradation of specific plastics and associated degradation mechanisms (Figure 3).

The degraders reported in the analysis period include bacteria (Table 1), fungi (Table 2), microalgae, microbial consortia, and insect larvae (Table 2), among others. Some of these microorganisms have been employed continuously while others only in specific years (Supplementary Figure S1). In the case of bacteria, they have been used consistently every year, reflecting their sustained effectiveness in plastic biodegradation. Fungi, although less frequent, have shown intermittent use, while microbial consortia, which combine bacteria and fungi, have recently gained interest because they combine the metabolic capabilities of several species to achieve more efficient biodegradation. These consortia can produce complementary enzymes that fragment plastic polymers faster and more effectively than individual microorganisms. Their ability to form biofilms improves the adhesion and decomposition of plastics, especially when their activity is stimulated with oxidizing agents such as H₂O₂, which enhances the production of key enzymes such as peroxidases (Skariyachan et al., 2021; Fachrul et al., 2024; Mohammadi et al., 2022) On the other hand, larvae have been occasionally employed, highlighting their potential in certain specific contexts (He et al., 2024; Burd et al., 2023; Yang et al., 2021) and algae (Sanniyasi et al., 2021) which represent an innovative strategy in LDPE biodegradation have also been used sporadically. This temporal distribution highlights the diversification of the methodologies applied to biodegradation in recent years, with an increasing trend toward the use of microbial combinations, as well as the exploration of new degraders such as larvae and algae.

Studies on LDPE biodegradation demonstrate varying efficiencies depending on the organism and conditions. Weight loss percentages range from 1.50 to 88.50%, with Zophobas atratus larvae achieving the highest reduction (88.50% in 45 days) (Wang et al., 2022). Fungi such as Aspergillus niger (Sáenz et al., 2019), and bacteria like Alcaligenes faecalis (Nag et al., 2021), also show promising results, with weight loss exceeding 20% in specific setups. These results highlight the diverse potential of biological agents in plastic degradation and the differences in percentages of weight loss (Table 3).

Each type of organism has unique degradation capabilities that are influenced by its origin, environmental conditions, and previous treatments. Table 4 presents some advantages and disadvantages of the different organisms in the process of biodegradation of plastics. In the case of degrading bacteria, they commonly belong to genera such as Pseudomonas, Bacillus, Streptomyces and Rhodococcus. Pseudomonas putida (Li et al., 2024), is known for its ability to degrade polyesters, whereas Bacillus subtilis (Kumar Gupta and Devi, 2019), has shown successful degradation of polystyrene. Fungi have a significant advantage due to their ability to secrete large amounts of enzymes such as; peroxidase, and lignin peroxidase enzymes outside their cells, which allows the degradation of complex polymers in the immediate environment (Wang et al., 2019); this characteristic has enabled multiple assays in plastic degradation. One example is Rhodotorula mucilaginosa, a fungus isolated from marine sediments.

In recent studies, this fungus was exposed to polyethylene treated with ultraviolet (UV) radiation, a pretreatment that favors plastic biodegradation (Giyahchi and Moghimi, 2023). Therefore, the ability of fungi to degrade plastics is not limited to only R. mucilaginosa species, but also to other fungi, such as the genera Aspergillus, Penicillium, and Fusarium, as they have also shown potential in the biodegradation of different types of plastics. For example, Aspergillus niger (Fachrul et al., 2024), has been reported for its ability to degrade polyurethane, while Penicillium chrysogenum (Khan et al., 2023), and Fusarium solani (Wróbel et al., 2023), have shown effectiveness in the degradation of polyethylene and polypropylene. Certain microorganisms can produce compounds that facilitate the decomposition of plastic by other organisms in the consortium, this is due to the release of compounds such as organic acids, peroxides, and other secondary metabolites (Tiwari et al., 2024; Wang et al., 2023), which modify the structure of the plastic and make it more susceptible to enzymatic degradation.

As for the enzymes, laccase, peroxidase, and cutinase (Gao et al., 2022; Tamnou et al., 2022), are some of the most studied in this context. These enzymes can break the chemical bonds of plastic polymers, facilitating their decomposition into monomers and other simpler compounds, such as carbon and carbon dioxide (CO₂). Often, this material is integrated into the organism as part of its carbon source. However, the production of these enzymes may be limited by factors such as nutrient availability, pH, temperature, and the presence of specific inducers, such as plastid-related substrates and cofactors necessary for enzymatic activity (Khandare et al., 2022; Li et al., 2023).

The biodegradation of plastics using larvae has emerged as a novel and promising approach. Various insect species, in particular the larvae of certain beetles and flies, have demonstrated the ability to degrade plastics through their digestive processes. This approach not only offers an environmentally friendly alternative for plastic waste management but can also be integrated with sustainable agricultural practices. One documented case is the beetle Tenebrio molitor, commonly known as the mealworm. Larvae of T. molitor can degrade plastics such as PS and PE (Wang et al., 2023; Wang et al., 2024). This process is facilitated by the presence of symbiotic microorganisms in the larval digestive system, which produces enzymes such as alkane monooxygenase (Zaman et al., 2024), and laccase (Kundungal et al., 2021), that are capable of breaking down these polymers into smaller carbon chains and sometimes into CO₂ and water. T. molitor larvae can consume approximately 34–39 mg of EPS, a plastic widely used in containers and packaging (Wang et al., 2022). As a result, EPS is oxidized and fragmented, with a significant reduction in its molecular weight. However, many times plastic can be integrated into the same organism of larvae in the form of microplastics and nanoplastics, and although it may seem insignificant this can be a problem since the end of these larvae can be food for other larger organisms and indirectly can expand and integrate into their organism (Yang et al., 2021).

Another species, that has shown potential in the biodegradation of plastics, is the black soldier fly (Hermetia illucens). The larvae of H. illucens are known for their ability to break down organic matter and have been studied for their ability to degrade bioplastics such as polyhydroxyalkanoate (PHA) and polylactate (PLA), breaking down PLA into simpler compounds such as lactic acid and CO₂ (Wang et al., 2024). Therefore, this helps us to understand that the efficiency of larvae in biodegrading plastics is enhanced by the synergy between insects and the microorganisms present in their gut. Symbiotic bacteria and fungi produce a variety of hydrolytic enzymes, such as esterase, cutinase, and lipase, which are essential for the degradation of plastic polymers. In addition, the mechanical action of chewing and the intestinal movement of the larvae facilitates the fragmentation of the plastic, increasing the surface area exposed to enzymatic action, this process although not a decomposition is an important part of subsequent biodegradation processes (Ma et al., 2023).

The integration of plastic-degrading larvae in agricultural systems has multiple benefits. Not only does it contribute to reducing plastic waste in the agricultural environment, but it also produces valuable by-products such as frass, the so-called “insect excrement,” which can be used as an organic fertilizer. The resulting frass is applied to crops as fertilizer, and although the mature larvae can be fed for poultry or fish, creating a more sustainable and circular agricultural system, (Peng et al., 2022). However, the effect of possible micro and nano plastics on larvae should be studied in detail. Therefore, an integrated system model in on-farm plastic waste management could include the use of T. molitor larvae, where agricultural plastics such as PE mulch can be degraded in situ. Despite the promising potential, using larvae for biodegradation of plastics faces several challenges. One of the main ones is optimizing culture conditions to maximize degradation efficiency. In addition, it is necessary to ensure that micro-and nanoplastics do not enter the food chain, due to their negative effects such as drug resistance and new diseases (Shi et al., 2024).

Supplementary Figure S2 presents a comparative analysis of the average evaluation time for different organisms or substances used in the biodegradation of polyethylene. A great variability in the evaluation times is observed, which reflects both the diversity of the organisms studied and the complexity of the biodegradation processes. Some microorganisms such as Brevibacillus brevis (Tiwari et al., 2023), and the soil microbiome (Ma et al., 2023; Jayan et al., 2023; Maddison et al., 2023; Peng et al., 2023; Yuan et al., 2023; Zhang et al., 2023), stand out as having significantly long evaluation times, exceeding 450 days. This suggests that these microorganisms may have a slow biodegradation process, or that studies conducted with them have required a prolonged time to observe significant results. In contrast, the fungus Rhizopus sp. (Gupta and Devi, 2020), and the beetle Zophobas atratus (He et al., 2024; Yang et al., 2021; Lou et al., 2021; Sanluis-Verdes et al., 2022), show evaluation times in the range of 20–60 days, which could indicate higher biodegradation efficiency or studies designed for faster results. Different strains of Z. atratus and their combinations with other organisms such as Tenebrio molitor show a wide range of evaluation times, suggesting that the interaction between species and the specificity of the organisms used have a significant impact on biodegradation efficiency and the conditions they require.

Another notable aspect is the case of the bacterium Gordonia polyisoprenivorans (Wang et al., 2023), which has an intermediate evaluation time, which could be related to its specialized capabilities in the degradation of complex polymers but requires considerable time to demonstrate its effectiveness. The use of microbial consortia, such as Bacterial-Fungal Consortium (BFC) (Li et al., 2024; Adithama et al., 2023; Bao et al., 2023; Gong et al., 2023), seems to offer a robust strategy, with more efficient assessment times compared to some individual microorganisms, suggesting that cooperation between different types of microorganisms could accelerate the biodegradation process, so the outlook for such studies is encouraging, although interactions between different taxonomic groups could result in antagonism and competition, requiring careful observations to create partnerships that can work successfully. A deducible rule of thumb is that more specialized organisms, such as certain fungi and bacteria, tend to require less time for evaluation, whereas microbial consortia and microorganisms working in more complex environments may need longer times to show results. However, this may also indicate that, in the future, the development of optimized consortia and genetic engineering techniques could significantly reduce these times, making biodegradation faster and more efficient. It is worth mentioning that for practicality a single study that evaluated Soil microbiome and climatic conditions for 2,556 days was not represented in Supplementary Figure S2, more details in Supplementary Table S1.

Microorganisms, including bacteria and fungi, attach to the polymer surface using biofilm-forming mechanisms and secrete compounds like exopolysaccharides and surfactants to further degrade the structure (Sáenz et al., 2019; Elsamahy et al., 2023). During biofragmentation, extracellular enzymes such as hydrolases, laccases, and esterases break down long polymer chains into smaller oligomers and monomers (Li et al., 2024). The efficiency of this stage depends on the chemical composition, crystallinity, and hydrophobicity of the polymers, as well as the availability of cofactors like oxygen and nutrients. Once fragmented, the smaller compounds are taken up by microbial cells in the assimilation stage, where they undergo intracellular metabolic processes to produce energy, biomass, and intermediate metabolites (He et al., 2024). Factors like microbial metabolic diversity, the availability of electron donors and acceptors, and community interactions significantly influence this stage (Sunny and Saleena, 2020). The final phase, mineralization, involves the complete degradation of organic matter into inorganic molecules such as carbon dioxide, water, and methane (El-Sayed et al., 2021; Zahari et al., 2021; Khan et al., 2023). This stage is heavily influenced by environmental parameters, including pH, redox potential, and oxygen availability, which dictate whether the process occurs under aerobic or anaerobic conditions (Obaid and AL-Jawhari, 2023). In addition to these environmental factors, microbial interactions play a critical role in enhancing biodegradation efficiency. Cooperative relationships, such as cross-feeding and enzyme complementation, improve substrate utilization, while competitive interactions can reduce efficiency by limiting resource availability (Pinto et al., 2022). Operational parameters, such as temperature, moisture content, agitation, and nutrient supplementation, are also key drivers of biodegradation outcomes. These factors, extensively studied in the literature, underline the complexity of the process, demonstrating how microbial and environmental conditions synergistically dictate the transformation of polymers into simpler, environmentally benign products, such as carbon dioxide, water, and biomass (Temporiti et al., 2022; Thomas Zumstein et al., 2018; He et al., 2024; Figure 1).

The parameters influencing biodegradation efficiency in the reviewed studies are diverse and often interdependent, highlighting the complexity of this process. Key variables include microbial interactions, operating conditions, and substrate-specific characteristics. For instance, Rhodotorula mucilaginosa demonstrated varied efficiency depending on the UV pre-treatment duration and the addition of 13C-PE as a sole carbon source (Vaksmaa et al., 2023). Similarly, the inclusion of enriched media, such as mineral salt broth inoculated with Gordonia polyisoprenivorans, enhanced LDPE degradation over 35 days, emphasizing the role of nutrient availability and sterilization methods (Tiwari et al., 2023) incorporating microbial consortia, such as Bacillus licheniformis and Achromobacter xylosoxidans, further underscore the significance of synergistic microbial interactions, which enhance degradation pathways (Fachrul et al., 2024). Environmental conditions also critically impact biodegradation outcomes. Temperature, pH, and agitation significantly influenced results, as seen with Bacillus subtilis, which required optimized incubation parameters to achieve notable LDPE degradation (Mohammadi et al., 2022). Furthermore, pre-treatment processes, such as UV irradiation or chemical oxidation, were consistently noted to enhance microbial attachment and enzymatic activity, as demonstrated in Microbulbifer hydrolyticus experiments with LLDPE particles (Li et al., 2020), in the S1 the columns “Organism or substance and its origin,” “Type of degrader,” “Pre-treatment condition and initial size,” “Treatments,” and “Evaluation Time” can give an extent analysis about this point.

In LDPE biodegradation studies, the physical form of the plastic plays an important role in the interaction with the degrading organisms. The different presentations of the plastic, such as films, powder, sheets, beads, granules, and foams, among others (Supplementary Table S2), affect the surface area available for adhesion and subsequent degradation. In the publications analyzed, 46% used plastics in the form of films (Supplementary Figure S3), this form offers a larger surface area in contact, which favors adhesion and colonization (Skariyachan et al., 2021; Huang et al., 2022; Jeon et al., 2021; Kong et al., 2024; Puglisi et al., 2019). Their advantage lies in their similarity to agricultural plastics, such as mulching films, making them relevant models in these studies. Their disadvantage is their thickness and low resistance to aggressive pretreatment, which may disintegrate them before completing biodegradation. The plastic powder was 18.4%, and the reduced particle size positively influences the rapid interaction with microorganisms (Tiwari et al., 2023; Bernat et al., 2023; Montazer et al., 2021; Pathak and Navneet, 2023; Yang et al., 2022). Their limitation is the additional mechanical pretreatment for their production, hindering complexity in the practical application of the biodegradation process in the agricultural sector. 16.1% report the use of sheets, which are more manageable and have greater durability compared to pretreatments. In some cases, they may take longer to degrade due to their thickness (Pinto et al., 2022; Zaman et al., 2024; Yuan et al., 2023; Hou et al., 2022; Joshi et al., 2022; Mishra et al., 2024), Bags with 6.9% represent a high surface-to-volume ratio, which favors biodegradation. The main difficulty of this form is the uniformity of the experimental conditions and their respective comparisons with other studies, taking into account the different sizes and thicknesses (Jayan et al., 2023; Gerritse et al., 2020; Mohy Eldin et al., 2022; Nademo et al., 2023; Nnaji et al., 2021; Poma et al., 2022) LDPE foams with 5.75% present a porous structure that increases the interaction with microorganisms, allowing better penetration of nutrients and microbial enzymes, and accelerating the biodegradation process. Its limitation is the difficulty of the precise quantification of the degraded material (Yang et al., 2021; Peng et al., 2022; Lou et al., 2021; Wang et al., 2022), Granules (4.6%) and beads (2.3%), being more compact in shape, reducing the surface area available for microbial colonization, reducing biodegradation efficiency. However, as they are easy to manipulate and quantify, they are useful in small-scale studies (Khandare et al., 2022; Adithama et al., 2023; Dey et al., 2020; Kunlere et al., 2019; Zadjelovic et al., 2022).

Most studies report the pretreatment of the plastic in the biodegradation process, taking into account that this increases its susceptibility to microbial degradation. One of the most common treatments is exposure to UV radiation, a process that partially degrades the plastic, facilitating its decomposition by modifying its physical and chemical properties (Yuan et al., 2023; Chaudhary et al., 2023; Min et al., 2020; Montazer et al., 2020). To mention an example, LDPE treated with UV radiation for 48 h develops carbonyl groups and peroxides on its surface, which enhances the adhesion and activity of bacteria isolated from landfills, resulting in higher production of degrading enzymes and a higher biodegradation rate compared to untreated plastics (Soleimani et al., 2021). In the case of polyester, chemical treatment with nitric acid facilitates its decomposition by bacteria of the genus Pseudomonas. Culture conditions also play a key role in biodegradation, as factors such as optimum temperature (30°C for HDPE), pH (7.0 for polystyrene), and the availability of nutrients, such as glucose, influence microbial activity (Ji et al., 2023).

By using plastic as the sole or main carbon source, a selective pressure is induced that forces the organism to consume the polymer, which allows observing its behavior and evolution under these challenging conditions. Culture conditions, such as temperature, pH, and nutrient availability, are critical factors affecting microbial activity and the efficiency of plastic biodegradation. Most studies maintain controlled conditions to optimize the activity of the degrading organisms, varying these conditions according to the type of organism and plastic to be degraded. Aderiye et al. (2019), in their study published in 2023 found that the optimum temperature for the biodegradation of HDPE by bacteria isolated from a waste landfill was 30°C. On the other hand, Chaudhary et al. (2023), found that a pH of 7 was optimal for the enzymatic activity of Pseudomonas fluorescens in the biodegradation of polystyrene. DSouza et al. (2021), showed that the addition of glucose in the experimental setups as an additional carbon source increased the rate of polypropylene biodegradation by Aspergillus niger. Oxygen concentration is another crucial factor that can influence the biodegradation of plastics. In one study, bacteria of the genus Bacillus were found to be more effective in the degradation of polyethylene under aerobic conditions, while bacteria of the genus Clostridium showed higher efficiency under anaerobic conditions (Islami et al., 2019; Fibriarti et al., 2021).

Biodegradation of polyethylene in agricultural systems faces limitations due to the chemical nature of this polymer and the specific conditions of agricultural environments. PE, widely used in agricultural plastics such as mulching and coverings, has a molecular structure with highly stable carbon–carbon bonds, which makes its biological decomposition difficult (Hou et al., 2022). In these systems, soil organisms, such as larvae, and microorganisms such as fungi and bacteria, must compete with other more accessible carbon sources, which reduces the metabolic priority of PE and slows down its biodegradation (Yang et al., 2021; Montazer et al., 2020). Environmental factors such as temperature, pH, humidity, and nutrient availability vary considerably in the soil, limiting the enzymatic activity necessary for polymer decomposition (Montazer et al., 2020). In many cases, PE requires pretreatments to increase its bioavailability to microorganisms. Exposure to UV radiation or the use of oxidizing agents can partially break the polymer chains, increasing the susceptibility of the plastic to biodegradation (Yuan et al., 2023). However, these pretreatments not only increase operational costs but can also generate byproducts that alter soil microbial dynamics or negatively impact the quality of the agricultural ecosystem. Smaller fragments, such as microplastics generated by partial degradation of mulch, can be integrated into the soil, which presents a double challenge: on the one hand, they increase the contact surface for microorganisms, but on the other, they pose ecological risks by being transported to other parts of the ecosystem and incorporated into food chains. Intermediate products generated during biodegradation, such as low molecular weight compounds, must be assessed at a toxicological level, to ensure that they do not interfere with soil health or crops (Nelson et al., 2022).