Complete Biodegradation Research Articles

Biodegradability of polyethylene: Challenges and future perspectives

Polyethylene (PE) is the second most abundant plastic worldwide due to its broad application in manufacturing disposable materials such as bags and bottles. Since it is highly resistant to natural biodegradation, it can accumulate in landfills, causing various ecological and toxicological consequences. Even though microbial degradation of PE has been extensively investigated, complete biodegradation of PE has yet to be achieved, and comparisons of PE biodegradation experiment findings are not practical. This may be due to the wide variety of PE substances used, and a wide variety of culture conditions, and many of the published findings still need key chemistry of PE materials, as well as basic biochemistry and microbiology. This review highlights the need for standardization in PE biodegradation studies and defining key biochemical terms. It aims to identify deficiencies and challenges in PE degradation experiments, enhancing future research for scientific and technological advancement. This review provides a biochemically based definition of PE biodegradation and summarizes microorganisms responsible for PE biodegradation. We also caution readers about the chemical makeup and structure of the PE, as well as the approaches utilized in microbes’ isolation. This review defines the fundamental elements required to conduct an effective PE biodegradation investigation.

Enhanced Antimicrobial and Degradable Properties of Silver Nanoparticles‐Reinforced Chitosan‐Indian Gooseberry Films for Sustainable Food Packaging

AbstractThis study focuses on creating a biodegradable film composed of chitosan, Indian Gooseberry (IG) extract, and silver nanoparticles (AgNPs), designed to enhance antimicrobial properties and improve food preservation. The presence of AgNPs and IG extract not only dramatically exhibits 99% efficiency in the antimicrobial activity against Staphylococcus aureus (ATCC 6538P), but also achieves this within a remarkably short time interval of ≈20 min. This potent antimicrobial action is attributed to the synergistic effect between the bioactive compounds in the IG extract and the nanoscale silver particles, which together create a highly hostile environment for microbial growth. Moreover, this synergy contributes to 313.94% water vapor transmittance rate and the complete biodegradability of the composite film (93.42% at the end of the second month), ensuring that it leaves no harmful residues in the environment post‐use. The reinforced film exhibits improved hydrophobicity (55.43%), which is crucial for protecting food products from moisture and extending their shelf life. Specifically, the film has been tested as a packaging material for bread, showing a significant extension in shelf life by effectively preventing mold growth and retaining freshness for an extended period (14 days).

Biodegradation of Heterogeneous Industrial Multi-Walled Carbon Nanotubes by Pro-Inflammatory Macrophages.

Industrial multi-walled carbon nanotubes (ig-MWCNTs) make up the majority of carbon nanomaterials, and human contact with them is the most probable. At the same time, the biodegradation of ig-MWCNTs by phagocytes has not been studied-existing articles consider mainly laboratory-grade/functionalized MWCNTs (l-MWCNTs), in contrast to which ig-MWCNTs are a highly heterogeneous nanomaterial in terms of morphological and physicochemical characteristics. The aim of the present study was to analyze ig-MWCNTs' biodegradation by proinflammatory macrophages. We focused on both extra- and intracellular ig-MWCNTs' degradation. We analyzed biodegradation of two different types of ig-MWCNTs by human (THP-1) and murine (RAW264.7) macrophages. After 10 days of incubation, we studied nanoparticle localization within cells; isolated intra- and extracellular ig-MWCNTs were used for quantitative analysis. Ultrastructural and morphometric analysis were performed using transmission electron microscopy; electron diffraction was used for nanotube identification. To estimate chemical alterations, energy-dispersive X-ray spectroscopy and Raman spectroscopy were used. The study showed that both intra- and extracellular ig-MWCNTs undergo almost complete biodegradation, but in different ways: intracellular nanotubes become perforated and reduce to graphene flakes, while extracellular become thinner. We believe that the demonstrated variability in the destruction of ig-MWCNTs by cells suggests the possibility of creating nanomaterials with controlled biodegradation properties.

Complete biodegradation of glyphosate with microbial consortium YS622: Structural analysis, biochemical pathways, and environmental bioremediation

The large-scale use of glyphosate has led to the continuous accumulation of residues in the environment, disrupting ecological balance and posing a threat to human health. The main objective of this study was to investigate the potential role of microbial consortium YS622 for the bioremediation of glyphosate-contaminated water/soil environments. YS622 could degrade 100 % of 50 mg/L glyphosate within 36 h, an efficiency higher than that of any other consortia or pure microorganisms reported so far. The kinetic parameters of maximum specific degradation rate, half-rate constant, and inhibition coefficient were determined to be 0.2 h−1, 139.0 mg/L, and 25.1 mg/L, respectively. YS622 metabolized glyphosate via the aminomethylphosphonic acid pathway via breaking the C–N bond. In addition, the sequencing analysis revealed that Azospirillum, Cloacibacterium, and Ochrobactrum were the dominant genera of YS622 in the degradation process, indicating that these genera might play pivotal roles in glyphosate biodegradation. Furthermore, the inoculation of YS622 in both sterilized and unsterilized water–sediment systems significantly promoted the degradation of glyphosate, with over 97 % degradation of 60 mg/L glyphosate within 36 h. The discovery of YS622 fills a gap in the synergistic metabolism of glyphosate at the community level and provides a potential candidate for bioremediation applications.

A multi-layer antimicrobial cellulose filter with electrostatic adsorption properties prepared by coating cellulose with chitosan and CuO

The health impacts of air pollution such as particulate matter (PM) and bioaerosols have prompted a focus on the utilization of personal protective filters. Traditional filters pose environmental concerns due to their non-biodegradable composition, while cellulose presents a promising alternative for biodegradable air filtration applications. This research involved the development of cellulose filter substrates with a customizable pore structure by adjusting the nanofiber content in cellulose filters and employing a simultaneous freeze-drying method. By integrating chitosan and CuO nanoparticles, the filters gained electrostatic adsorption capabilities, leading to a substantial enhancement in filtration efficiency, as well as imparting moisture resistance and durable antimicrobial properties to the filter. Subsequently, a three-layer cellulose filter integrated with chitosan and CuO (abbreviated as Int-Cs&CuO) was constructed based on the generalized Murray’s law to enable multi-stage PM filtration. The Int-Cs&CuO cellulose filter demonstrated filtration efficiencies of 99.2 % for non-oily PM0.3 and 99.5 % for oily PM0.3, with a low pressure drop of 49.5 Pa. Under humid conditions, the filtration efficiency of the Int-Cs&CuO cellulose filter against PM0.3 particles was minimally impacted, showcasing a decrease of only 1.3 %. Notably, the filter exhibited complete biodegradation in composted soil within approximately 2 months.

Half substitution of mineral N with fish protein hydrolysate enhancing microbial residue C and N storage and climate benefits under high straw residue return

The widespread utilization of straw return was a popular practice straw disposal for highly intensive agriculture in China, which has brought about some negative impacts such as less time for straw complete biodegradation, aggravation of greenhouse gas evolution, and lower efficient of carbon accumulation. It was urgent to find an eco-friendly N-rich organic fertilizer instead of mineral N as activator to solve the above problems and lead a carbon accumulation in long tern management. Besides, microbial necromass was considered as a crucial contributor to persistent soil carbon (C) and nitrogen (N) pool. How organic fertilizer activators influence microbial residue under different amount of crop residues input remained unclear. Thus, soils incorporating moderate and high rate of rice straw residue with additions of half and full of organic activators (fish protein hydrolysates vs. manure) were incubated for measuring carbon dioxide (CO2) and nitrous oxide (N2O) emission, microbial community and necromass. It was found that soil CO2 emission was rapidest during the first 13 days of straw decomposition but remained lowest in the treatments of 50% mineral N substituted by fish protein hydrolysate. There were that 81%–89% of total CO2 release and 59%–65% of total N2O emission occurred within 60 days of incubation period, and bacterial community and nitrate positively affected soil CO2 and N2O release respectively. Straw incorporation amount and organic activator application interactively influenced soil CO2 emission but not affected soil N2O emission. After 360 days of incubation, the difference of bacterial necromass was noticeable but fungal necromass remained almost unaltered across all treatments. All treatments showed generally comparable contribution of microbial necromass N to the total N pool. The treatment of 50% mineral N substituted by fish protein hydrolysate under high rate of straw input (HSF50) promoted the highest proportion of microbial necromass C in soil organic C because of alleviating N limitation for microorganisms. Finally, HSF50 was recommended as an eco-friendly strategy for enhancing microbial necromass C and N storage and climate benefits in agroecosystems.

All-cellulose triboelectric textile with complete biodegradability for eco-friendly smart wearable electronics

All-cellulose triboelectric textile with complete biodegradability for eco-friendly smart wearable electronics

A robust, high-temperature-resistant, protective cellulose gel enabled by multiscale structural engineering

Given the escalating environmental and safety concerns, friendly protective materials with exceptional mechanical properties, biodegradability, and insensitivity to high temperature have received more and more attention. Here, we report a robust cellulosic gel through the multi-scale integration of cellulose molecular skeleton, nano-reinforced diatomite, and in situ polymerized polyacrylamide molecule. The bottom-up yet cross-scale approach facilitates the formation of cellulosic gel characterized by a highly interconnected hydrogen bond network and nano-enhanced domain, resulting in a tensile strength of up to 13.83 MPa, a Young's modulus exceeding 280 MPa, and an impact strength around 12.38 KJ m−1. Furthermore, this gel exhibits structural stability at temperatures up to 130 °C, good flame retardancy, and complete biodegradability within a span of 35 days. The robust cellulosic gel, acting as a pliable protector, demonstrates exceptional protection for human joints. Our study presents a highly efficient and scalable pathway towards the development of sustainable and robust biomass gels, holding immense potential in intelligent-protective wearables and advanced materials science and engineering.

Incorporation of Polygonatum cyrtonema extracts of NADES into chitosan/soybean isolate protein films: Impact on sweet cherry storage quality

This study developed a biodegradable food film, incorporating bioactive components of Polygonatum cyrtonema extracted using natural deep eutectic solvents (NADES) into a matrix of chitosan and soy protein isolate. The films containing varying concentrations (0 %–5 %) of P. cyrtonema extract (PCE) were characterized. The addition of PCE improved the mechanical (+25.9 MPa for tensile strength), optical (+11.29 mm−1 for opacity), and thermal stability (−14.39 % for weight loss) of the films. The DPPH and ABTS radical scavenging rates increased by approximately 1.1 times and 0.5 times, respectively, and malondialdehyde formation reduced by 8 %. The films also effectively inhibited the growth of Staphylococcus aureus or Escherichia coli. The films showed complete biodegradability after 7 days. Using the NADES-PCE coated film reduced the weight loss of sweet cherries by 41.04 % while significantly decreasing the loss of hardness, total phenols, vitamin C, total soluble solids, and titratable acidity, thereby considerably extending the storage life of the sweet cherries. Overall, this study developed a new environmentally friendly packaging material and improved the functionality of the packaging film by leveraging natural plant extracts, demonstrating tremendous potential in the field of food preservation and packaging.

Alternative end-of-life options for disposable bioplastic products: Degradation and ecotoxicity assessment in compost and soil

Four different end-of-life options for disposable bioplastic cups were investigated and compared based on their environmental implications. Two products with distinct polymeric composition were tested simulating the following scenarios at laboratory scale: i) industrial composting (180 days at 58 °C); ii) anaerobic digestion followed by industrial composting (45 days at 55 °C and 180 days at 58 °C); iii) anaerobic digestion followed by direct digestate use on soil for agricultural purposes (45 days at 55 °C and 180 days at 25 °C); iv) uncontrolled release into a soil environment (180 days at 25 °C). Ecotoxicity tests were run at the end of each experiment to investigate the effects of the materials on three main groups of terrestrial model organisms: plants, earthworms and nitrifying bacteria. Complete biodegradation of the cups was observed in 180 days in the scenarios involving composting environment. A low degree of biodegradation (22.9 ± 4.5%) of the digestates in soil was observed, warning for a potential micro-bioplastics discharge into the environment. No degradation was observed for the cups in soil during the same testing period. Ecotoxicity tests revealed a negative effect on plants biomass growth across all samples, which was 17–30% lower compared to the blank sample. The experimental campaign highlighted the need for a systematic assessment of controlled treatment of bioplastics, as well as the need for a harmonized legislative framework.

Preparation and properties of thermoplastic starch under the synergism of ultrasonic and elongational rheology

Thermoplastic starch, as an eco-friendly alternative to petroleum-based plastics, possesses numerous advantages, including cost-effectiveness, complete biodegradability, and renewable sourcing. Nevertheless, the plasticizer dispersion and starch plasticization efficiency are poor via the processing method dominate by shear deformation. Thus, the aim of this study is proposing a new approach combining ultrasonic treatment and elongational rheology to prepare thermoplastic starch and evaluate its properties. This innovative approach facilitated the production of thermoplastic starch with glycerol as the plasticizer at varying rotor speeds. Furthermore, this study was carried out by using a self-developed ultrasonic-assisted vane mixer (UVM) based on elongational flow. The samples were analyzed using FTIR, WAXD, polarized optical microscope, dynamic rheometer, universal testing machine and thermogravimetric analysis. FTIR and dynamic rheological analysis showed that elongational rheology and ultrasonics stimulate hydrogen bond formation between starch and glycerol, elevating starch thermoplasticity. Tensile tests and thermogravimetric analysis highlighted that high-intensity elongational field improved the mechanical properties and thermal stability of the thermoplastic starch. Additionally, the incorporation of ultrasonic treatment yielded further improvements, yielding remarkable tensile strength (6.09 MPa) and elongation at break (139.3 %). This synergistic interplay between ultrasonics and elongational rheology holds immense potential for advancing thermoplastic starch manufacturing.

Biodegradation behavior of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) containing phenolic compounds in seawater in laboratory testing conditions

Biodegradation in marine medium of PHBV films with or without 5 % wt. of phenolic compounds (catechin, ferulic acid, and vanillin) was assessed at laboratory scale. Respirometric analyses and film disintegration kinetics were used to monitor the process over a period of 162 days. Structural changes in the films were analyzed throughout the exposure period using FESEM, DSC, Thermogravimetric analyses, XRD, and FTIR spectra. Respirometric tests showed complete biodegradation of all materials during the exposure period (the biodegradation half-time ranged between 63 and 79 days) but at different rates, depending on the phenolic compound incorporated. Ferulic acid and vanillin accelerate the PHBV biodegradation, whereas catechin delayed the process. Disintegration kinetics confirmed these results and showed that degradation occurred from the surface to the interior of the films. This was controlled by the degradation rate of the polymer amorphous phase and the formation of a biomass coating on the film surface. This is the result of the compounds generated by polymer degradation in combination with excretions from microorganisms. This coating has the potential to affect the enzyme diffusion to the polymer substrate. Moreover, the cohesion forces of the amorphous phase (reflected in its glass transition temperature) affected its degradation rate, while the slower degrading crystalline fragments were released, thus contributing to the disintegration process on the film's surface. Ferulic acid, with its hydrolytic effect, enhanced degradation, as did vanillin for its plasticizing and weakening effect in the amorphous phase of polymer matrix. In contrast, catechin with cross-linking effect hindered the progress of the material degradation, considerably slowing down the process rate.

Molecular engineering of PETase for efficient PET biodegradation

The widespread utilization of polyethylene terephthalate (PET) has caused a variety of environmental and health problems. Compared with traditional thermomechanical or chemical PET cycling, the biodegradation of PET may offer a more feasible solution. Though the PETase from Ideonalla sakaiensis (IsPETase) displays interesting PET degrading performance under mild conditions; the relatively low thermal stability of IsPETase limits its practical application. In this study, enzyme-catalysed PET degradation was investigated with the promising IsPETase mutant HotPETase (HP). On this basis, a carbohydrate-binding module from Bacillus anthracis (BaCBM) was fused to the C-terminus of HP to construct the PETase mutant (HLCB) for increased PET degradation. Furthermore, to effectively improve PET accessibility and PET-degrading activity, the truncated outer membrane hybrid protein (FadL) was used to expose PETase and BaCBM on the surface of E. coli (BL21with) to develop regenerable whole-cell biocatalysts (D-HLCB). Results showed that, among the tested small-molecular weight ester compounds (p-nitrophenyl phosphate (pNPP), p-Nitrophenyl acetate (pNPA), 4-Nitrophenyl butyrate (pNPB)), PETase displayed the highest hydrolysing activity against pNPP. HP displayed the highest catalytic activity (1.94 μM(p-NP)/min) at 50 °C and increased longevity at 40 °C. The fused BaCBM could clearly improve the catalytic performance of PETase by increasing the optimal reaction temperature and improving the thermostability. When HLCB was used for PET degradation, the yield of monomeric products (255.7 μM) was ∼25.5 % greater than that obtained after 50 h of HP-catalysed PET degradation. Moreover, the highest yield of monomeric products from the D-HLCB-mediated system reached 1.03 mM. The whole-cell catalyst D-HLCB displayed good reusability and stability and could maintain more than 54.6 % of its initial activity for nine cycles. Finally, molecular docking simulations were utilized to investigate the binding mechanism and the reaction mechanism of HLCB, which may provide theoretical evidence to further increase the PET-degrading activities of PETases through rational design. The proposed strategy and developed variants show potential for achieving complete biodegradation of PET under mild conditions.

The Interaction of Microplastics and Microbioplastics with Soil and a Comparison of Their Potential to Spread Pathogens

Microplastics contribute to various environmental issues and serve as carriers for a wide range of toxic compounds such as pesticides, pharmaceuticals, and metal ions. Consequently, there is a gradual shift towards replacing them with biodegradable plastics (bioplastics). However, biodegradable plastics require specific conditions for complete biodegradation, and their biodeterioration often leads to the rapid production of smaller fragments, known as microbioplastics. In this review, we summarize selected issues related to the impact of plastic particles on soil properties and the soil microbiome. Findings from numerous studies indicate that both microplastics and microbioplastics induce adverse changes in soil microbiology, potentially increasing the abundance of soil-borne pathogens. Based on these observations, we argue that plastic particles could serve as carriers for colonies of soil-borne pathogens. Furthermore, the use of bioplastics may exacerbate this issue due to their easier and faster formation, increased support for biofilms, and more pronounced adverse effects on soil biota. However, further research is necessary to either substantiate or refute this perspective.

Starch-based biodegradable films amended with nano-starch and tannic acid-coated nano-starch exhibit enhanced mechanical and functional attributes with antimicrobial activity

Starch-based biofilms are biodegradable, but their application is limited by lower mechanical strength and absence of antimicrobial properties. In this context, the present study attempted to unleash the potential of nanotechnology for synthesizing nano-starch (NS) and tannic acid-coated nano-starch (T-NS) for augmenting the tensile strength and antimicrobial properties of starch-based biofilms. Moreover, this study reports one of the first such attempts to improve the commercial viability of starch extracted from the corms of Amorphophallus paeoniifolius. In this study, NS and T-NS samples were first synthesized by the physical and chemical modification of the native starch (S) molecules. The NS and T-NS samples showed significantly smaller granule size, lower moisture content, and swelling power. Further, amendments with NS and T-NS samples (25 % and 50 %) to the native starch molecules were performed to obtain biofilm samples. The NSB (NS amended) and T-NSB (T-NS amended) biofilms showed comparatively higher tensile strength than SB films (100 % starch-based). The T-NSB showed greater antimicrobial activity against gram-positive and gram-negative bacteria. All the biofilms showed almost complete biodegradation in soil (in 10 days). Therefore, it can be concluded that additives like NS and T-NS can improve starch-based biofilms' mechanical strength and antimicrobial properties with considerable biodegradability.

Hydrostability, mechanical resilience, and biodegradability of paper straws fabricated through lignin-based polyurethane and chitosan binary emulsion bonding

This study focuses on enhancing the strength and water stability of paper straws through a novel approach involving a binary emulsion of lignin-based polyurethane and chitosan. Kraft lignin serves as the raw material for synthesizing a blocked waterborne polyurethane, subsequently combined with carboxylated chitosan to form a stable binary emulsion. The resulting emulsion, exhibiting remarkable stability over at least 6 months, is applied to the base paper. Following emulsion application, the paper undergoes torrefaction at 155 °C. This process deblocks isocyanate groups, enabling their reaction with hydroxyl groups on chitosan and fibers, ultimately forming ester bonds. This reaction significantly improves the mechanical strength and hydrophobicity of paper straws. The composite paper straws demonstrate exceptional mechanical properties, including a tensile strength of 47.21 MPa, Young's modulus of 4.33 GPa, and flexural strength of 32.38 MPa. Notably, its water stability is greatly enhanced, with a wet tensile strength of 40.66 MPa, surpassing commercial paper straws by 8 folds. Furthermore, the composite straw achieves complete biodegradability within 120 days, outperforming conventional paper straws in terms of environmental impact. This innovative solution presents a promising and sustainable alternative to plastic straws, addressing the urgent need for eco-friendly products.

Karakteristik Arang Kulit Buah Kakao dan Arang Batang Bambu Terhadap Mutu Briket

The purpose of this research is to determine the optimum properties of biodegradable plastic made from banana weevil starch with the addition of straw cellulose as reinforcement. This research was conducted using Completely Randomized Method (CRD) with four treatments and four replications. In this study were the addition of straw cellulose with a ratio of starch and cellulose 1:0; 1:0,5 ; 1:1 and 1:1,5. Tests were carried out on strong tensile strength, elongation at break, biodegradation, swelling and water vapor transmission rate. The data obtained were analyzed statistically using analysis of variance (ANOVA). The addition of straw cellulose had a significant effect on the manufacture of biodegradable plastics. The result were biodegradable plastic increase tensile strength, decreases elongation at break, increase biodegradation and air resistance, reduces the rate of water vapor transmission. Biodegradable plastic with the best treatment is the ratio of starch starch ratio of 1 : 1.5 cellulose. The best result biodegrabable plastic has for tensile strength value of 9.56 MPa, elongation 6.8%, complete biodegradation on day 6, swelling 41.51% and WVTR 0.0156%.

Complete biodegradation of tetrabromobisphenol A through sequential anaerobic reductive dehalogenation and aerobic oxidation

Tetrabromobisphenol A (TBBPA), a common brominated flame retardant and a notorious pollutant in anaerobic environments, resists aerobic degradation but can undergo reductive dehalogenation to produce bisphenol A (BPA), an endocrine disruptor. Conversely, BPA is resistant to anaerobic biodegradation but susceptible to aerobic degradation. Microbial degradation of TBBPA via anoxic/oxic processes is scarcely documented. We established an anaerobic microcosm for TBBPA dehalogenation to BPA facilitated by humin. Dehalobacter species increased with a growth yield of 1.5 × 108 cells per μmol Br- released, suggesting their role in TBBPA dehalogenation. We innovatively achieved complete and sustainable biodegradation of TBBPA in sand/soil columns columns, synergizing TBBPA reductive dehalogenation by anaerobic functional microbiota and BPA aerobic oxidation by Sphingomonas sp. strain TTNP3. Over 42 days, 95.11 % of the injected TBBPA in three batches was debrominated to BPA. Following injection of strain TTNP3 cells, 85.57 % of BPA was aerobically degraded. Aerobic BPA degradation column experiments also indicated that aeration and cell colonization significantly increased degradation rates. This treatment strategy provides valuable technical insights for complete TBBPA biodegradation and analogous contaminants.

Metal-ion-controlled hydrogel dressing with enhanced adhesive and antibacterial properties for accelerated wound healing

In order to improve the wound repair environment, this research has successfully developed a new multifunctional hydrogel dressing, which has strong adaptability and can accelerate wound healing. Pioneering the development of metal-ion-controlled hydrogel dressings, this research integrates dopamine and imidazole double crosslinked networks with metal-ion coordination. The resulting hydrogel dressing exhibits a notable antibacterial effect and exceptional mechanical properties, withstanding pressures of up to 12 kPa, tensions of 25 kPa, and maintaining skin adhesion at 6 kPa. Furthermore, the dressing can self-heal within only 7–8 s post-injection. Impressively, the hydrogel achieves complete biodegradation within a short timeframe (37 h). Notably, the use of various metal ions facilitates painless peeling during the degradation period, perfectly aligning with the requirements of an ideal wound dressing. This study has made significant progress in the fields of trauma repair and materials, providing strong solutions for dealing with harsh post-traumatic environments.

Upcycling Low-Quality Cotton Fibers into Mulch Gel Films in a Fast Closed Carbon Cycle.

Low-quality cotton fibers, often overlooked as low-value materials, constitute a marginalized waste stream in the cotton industry. This study endeavored to repurpose these fibers into mulch gel films, specifically exploring their efficacy in covering moisture-controlled soil beds. Through a meticulously designed series of processing methods, cellulose/glycerol film was successfully fabricated by regenerating cellulose hydrogels in N,N-dimethylacetamide/lithium chloride solutions, followed by plasticization in glycerol/water solutions and hot pressing. The film was then employed to cover soil beds for a duration of up to 252 days, followed by soil burial assessments. Despite expectations of degradation, the film maintained structural integrity throughout the soil covering period but underwent complete biodegradation after 80 days of soil burial, thereby completing a closed carbon cycle. Intriguingly, both tensile strength and modulus exhibited no diminishment but instead increased after soil covering, contrary to expectations given the usual role of degradation. Mechanistic insights revealed that the removal of glycerol contributed to the mechanical enhancement, while microbial activity predominately decomposed the amorphous regions in soil covering and targeted the crystalline portions in soil burial, elucidating the main biodegradation mechanisms. In summary, this study presents, for the first time, the potential of upcycling low-quality cotton fibers into high-value mulch gel films for agricultural practices within a closed carbon cycle.