Biodegradable Plastics Research Articles

Exploring the Cellulose Content on the Thermal and Mechanical Properties of Banana Peel Blend Tapioca Starch Bioplastic

Petrochemical polymers are convenient but harmful to humans and the environment. In response to growing environmental concerns over petroleum-based polymers, this study developed a biodegradable plastic made from tapioca and banana peel starch. Tapioca flour, banana peel starch, and 3g, 6g, and 9g of cellulose were used via solvent cast technique to fabricate bioplastic films. Fourier transform infrared spectroscopy shows strong peaks at 3400-3200 cm-1, corresponding to OH bond stretching vibrations for all obtained films. The bioplastics film displayed good performance in tensile testing when 6g of cellulose was used as compared to other formulations. Thermogravimetric analysis showed that adding cellulose enhanced the thermal properties where the temperature of 139.0394 ℃ (T20) and 140.16 ℃ (T50) shifted to a higher temperature when 9g cellulose was incorporated with the blend matrix. Interesting to note that 3g of cellulose absorbs the most water however 9g loses the least weight. This phenomenon is due to an increase in the cellulose-hydroxyl hydrogen bonding. On the other hand, the modified films are insoluble in acetic acid, moderately soluble in ammonia, and entirely soluble in sulphuric acid for solubility behaviour analysis. The banana peel starch blend and tapioca powder film modified with cellulose bioplastics have the potential to be applied ideally for food packaging.

Acceptorless Dehydrogenation of Glycerol Catalysed by Ir(III) Complexes with Carbohydrate‐Functionalised Ligands: A Sweet Pathway to Produce Hydrogen and Lactic Acid

AbstractGlycerol, a by‐product of biodiesel production, has gained prominence as a precious platform chemical. To enhance the economic viability of the biodiesel production process and address the surplus of glycerol production, it is essential to transform it into value‐added products. In this context, homogeneous catalysis offers a promising avenue for glycerol valorisation. In this study, we introduce a family of iridium complexes bearing picolineamidate ligands with glucose‐functionalised substituents as novel homogeneous catalysts for glycerol to hydrogen and lactic acid conversion. These complexes exhibit high activity (conversion up to 53.3 %) and 99 % selectivity after 24 hours of reaction (TOFMAX=159 h−1, TON24h=2498). Notably, the reaction occurs under ambient air and at milder temperature conditions (120 °C) compared to other catalysts. These efforts in glycerol valorisation contribute to reducing biodiesel production costs, increasing the competitiveness of biofuels against petroleum‐based liquid fuels, giving rise to H2, through a global process with negative carbon dioxide emission, and lactic acid utilizable, among other, as a monomer for the synthesis of biodegradable plastics.

Carbon preference by Cupriavidus necator for growth and accumulation phases: Heterotrophic vs. autotrophic metabolisms

Cupriavidus necator is a mixotrophic microbe capable of metabolizing both organic carbon (heterotrophic) and CO2 (autotrophic) for cell growth and biodegradable plastic synthesis. This study investigates C. necator's behavior under mixotrophic conditions for cell growth and polyhydroxyalkanoate (PHA) accumulation. Various concentrations of organic substrates (acetate and butyrate from 10 to 1000 mg/L) and gaseous substrates (H2, O2, CO2) were examined to monitor C. necator's substrate preferences. The results indicated a clear preference for organic carbon over CO2 during cell growth. At relatively low organic concentrations (10–100 mg/L), gas utilization began after complete consumption of organic substrates. On the other hand, higher concentrations (500–1000 mg/L) led to a shift from the heterotrophic to mixotrophic metabolism around the 10-h mark due to the abundance of substrates. During PHA accumulation, C. necator initially favored the gaseous substrates (H2 and CO2) before shifting to the organic substrates, with mixotrophic behavior observed immediately at low organic concentrations. Additionally, high CO2 partial pressure (>0.4 atm) inhibited microbial growth in both autotrophic and heterotrophic metabolisms. These findings highlight C. necator's adaptability under mixotrophic conditions and demonstrate the potential for mass-scale applications, such as microbial electrolysis cells to optimize biopolymer production and substrate utilization.

A sustainable approach to enhance biodegradability of recycled LDPE with starch biofillers derived from potato peels and rice husk ash*

ABSTRACT This study investigates the potential of using starch derived from potato peels and rice husks as biofiller for the production of biodegradable plastics. Starch was extracted from potato peels and modified using phthalic anhydride, formamide and potassium acetate to ensure its homogeneous dispersion into the low-density polyethylene (LDPE) matrix. The modified potato peel starch and rice husk ash were characterised using various techniques such as SEM, TEM, FTIR, XRD and were blended with recycled LDPE to enhance its biodegradability for making it an applicable environmental friendly packaging material. The quantity of the biofiller was varied from 4 to 12 g while rice husk ash content was kept constant (0.6 g). The addition of the biofiller reduced the tensile strength, tear strength and transparency of the film with an increase in haze %, weight loss both in garden soil and vegetable waste environment indicating the enhancement in biodegradability of the produced blend. Considering the applicability constrain biodegradable blend containing 20% starch was considered as the best one having tensile strength of approximately 10.42 MPa, tear strength 69.4 N, weight loss percentage of 13.29% in garden soil and 11.34% in vegetable waste when studied for a period of 360 days. Modification of starch has however increased both the mechanical (tensile strength – 12.628 MPa, tear strength – 80.47 N) and biodegradability (weight loss percentage of 15.19% in garden soil and 14.45% in vegetable waste) of the films when studied under the same conditions for the sample containing 30% starch in the matrix.

The biochemical mechanisms of plastic biodegradation.

Since the invention of the first synthetic plastic, an estimated 12 billion metric tons of plastics have been manufactured, 70% of which was produced in the last 20 years. Plastic waste is placing new selective pressures on humans and the organisms we depend on, yet it also places new pressures on microorganisms as they compete to exploit this new and growing source of carbon. The limited efficacy of traditional recycling methods on plastic waste, which can leach into the environment at low purity and concentration, indicates the utility of this evolving metabolic activity. This review will categorize and discuss the probable metabolic routes for each industrially-relevant plastic, rank the most effective biodegraders for each plastic by harmonizing and re-interpreting prior literature, and explain the experimental techniques most often used in plastic biodegradation research, thus providing a comprehensive resource for researchers investigating and engineering plastic biodegradation.

Optimizing plastic film mulch to improve the yield and water use efficiency of dryland maize in the Loess Plateau, China.

Knowledge on the variation of yield and water use efficiency under different mulching methods is important for guiding rained maize production in the Loess Plateau area. In this study, eight different plastic film mulching methods was established to analyze the maize growth, soil water content and soil temperature changes of dryland maize, and increase yield and water use efficiency (WUE). The field experiment was conducted in 2019, and eight treatments were set up, including a traditional flat planting without mulching (CK), ridge-furrow with ridges mulching black plastic film and furrows mulching straw (HJ), ridge-furrow with ridges mulching black plastic film and furrows bare (HL), ridge-furrow with ridges mulching liquid plastic film and furrows mulching straw (YJ), ridge-furrow with ridges mulching liquid plastic film and furrows bare (YL), ridge-furrow with ridges mulching biodegradable plastic film and furrows mulching straw (SJ), ridge-furrow with ridges mulching biodegradable plastic film and furrows bare (SL) and ridge-furrow with ridges bare and furrows mulching straw (NJ). Furthermore, the AHP-TOPSIS was employed to evaluate the optimal mulching method for maize. The results showed that compared with CK and NJ treatment, the soil water content and soil storage were significantly changes with other treatments in the reproductive period of maize. Among the six mulching methods, maize yield in HJ, HL, YJ, YL, SJ, and SL treatments were 46.28%, 61.95%, 70.30%, 51.02%, 52.02% and 53.53% significantly greater than CK treatment. In addition, dryland maize WUE was 66.53% and 84.01% higher in the YJ and YL treatments with ridges mulching liquid plastic film than in the CK treatment, respectively. The optimal treatments of economic benefits were YL and HJ. Through AHP-TOPSIS comprehensive analysis, the optimal mulching methods were YL and HJ treatment. Current field trials indicate that YL treatment could serve as a promising option to improve dryland maize yield, WUE, and reducing environmental risks in the Loess Plateau of China.

Biodegradable films incorporating Malaysian stingless bee propolis: Development, characterization, and potential for food packaging

Three different Malaysian stingless bee propolis samples were examined using the ethanolic extraction method for total flavonoid (TFC) and phenolic content (TPC), antioxidant, and antibacterial activities. Additionally, the biodegradable films were developed and characterized, this study also aims to enhance the functional qualities for possible use in active food packaging by combining corn starch (CS) with propolis extract (PE). The propolis samples were extracted with 70 % ethanol and analysed through a UV–VIS spectrophotometer for determination of antioxidant, TPC, and TFC. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) was used as scavenging test for free radicals, while Folin-Ciocalteu and aluminium chloride (AlCl3) were used to measure total flavonoid and phenolic contents. The data presented in this study showed significant differences in TPC and TFC identified in each sample ranged from 31.95 to 59.48 mg/mL GAE and 53.88 to 59.49 mg/mL RE, respectively. The findings also showed significant differences in the antibacterial activities of Malaysian stingless bee propolis, especially against Gram-positive bacterial strains. In comparison to the control treatments, the ethanolic propolis extract treatments also improved the film's physiochemical and antibacterial qualities. The incorporation of PE into CS resulted in decreased moisture content of the films from 17.20 % to 14.39 %, whereas the solubility significantly decreased from 17.44 % to 12.14 %. The weight of CS and PE film lowered significantly after 14 days and the weight loss percentage also demonstrated that bioplastic degradation occurred. The propolis extract was able to prevent the growth of foodborne bacteria since the present data revealed that the microbial count was significantly lower than control groups by displaying an acceptable limit of aerobic plate count for red meat products, which is lower than 6 log CFU/g. Propolis from Malaysian stingless bees may offer a viable substitute for synthetic additives in biodegradable food packaging films. Its antimicrobial and antioxidant properties support its application for sustainable food preservation.

Biodegradable microplastics induce profound changes in lettuce (Lactuca sativa) defense mechanisms and to some extent deteriorate growth traits

The development of agricultural technologies has intensified the use of plastic in this sector. Products of plastic degradation, such as microplastics (MPs), potentially threaten living organisms, biodiversity and agricultural ecosystem functioning. Thus, biodegradable plastic materials have been introduced to agriculture. However, the effects of biodegradable plastic substitutes on soil ecosystems are even less known than those of traditional ones. Here, we studied the effects of environmentally relevant concentrations of MPs prepared from a biodegradable plastic (a starch-polybutylene adipate terephthalate blend, PBAT-BD-MPs) on the growth and defense mechanisms of lettuce (Lactuca sativa) in CLIMECS system (CLImatic Manipulation of ECosystem Samples). PBAT-BD-MPs in the highest concentrations negatively affected some traits of growth, i.e., dry weight percentage, specific leaf area, and both C and N contents. We observed more profound changes in plant physiology and biochemistry, as PBAT-BD-MPs decreased chlorophyll content and triggered a concerted response of plant defense mechanisms against oxidative stress. In conclusion, exposure to PBAT-BD-MPs induced plant oxidative stress and activated plant defense mechanisms, leading to oxidative homeostasis that sustained plant growth and functioning. Our study highlights the need for in-depth understanding of the effect of bioplastics on plants.

The use of chain extenders as processing aids in the valorization of single-use polylactide (PLA) products by rotomolding

Biodegradable plastics in single-use products have increased in popularity as a way to reduce the negative environmental impact of conventional plastics and meet the tightening law regulations. However, their recyclability needs to be assessed, as the environmental behavior of single-use plastics, even if compostable, is not negligible. Polylactide (PLA) is susceptible to thermal, oxidative, hydrolytic, and mechanical degradation during reprocessing, so the conditions of such cycles must be accurately controlled. The necessity of using additives to reduce such degradations during rotational molding, a process with long cycle times and oxidizing atmosphere, has been demonstrated. Chain extenders based on a carbodiimide (Bioadimide® 100 - KI), a methylene diphenyl diisocyanate (MDI), and a polystyrene-acrylic copolymer (Joncryl® ADR-4368c - J) have been added to post-consumer PLA wastes. It has been demonstrated that these three chain extenders enabled obtaining a higher molecular weight of the reprocessed polymer, compared to the ∼50% reduction for the neat PLA. The use of carbodiimide yielded the most similar performance to that of unprocessed raw material. All samples provided adequate thermal stability and processing parameters for the rotational molding. Carbodiimide is considered the most efficient additive, as it increases the molecular mass of the polymer as it remains unchanged after processing. Similarly, KI-modified PLA rheological behavior remains unchanged after processing, which means this compound can reduce thermooxidative and hydrolytic degradation reactions. Thus contributing to the achievement of improved processability and better performance; in particular, impact strength increased from 1.06 ± 0.56 for PLA to 8.12 ± 2.28 kJ/m2 for KI-modified PLA, and toughness of 5.36 ± 1.61 to 61.49 ± 8.01 J/mm3, respectively, leading to rotomolded items without structural defects. On the opposite, the use of Joncryl® and MDI led to structural defects in the rotomolded parts despite a higher molecular weight of the polymer, which resulted in poor mechanical properties, although better than PLA without any additive. All three chain extenders resulted in an amorphous PLA structure with increased glass transition temperature and improved thermal stability, which correlated with the reduced emissions of volatile compounds compared to neat recycled PLA. The presented findings significantly contribute to a better understanding of PLA and its modifications at a molecular scale required for its efficient and possibly environmentally burden-free reprocessing. Gathered knowledge will be crucial for optimizing its environmental performance and widening its applications, particularly in a process with long cycle times and oxidative character, such as rotational molding.

Fungi's Degradation Capacity of Biodegradable Plastics

Fungi's Degradation Capacity of Biodegradable Plastics

Rainfall-induced microplastic fate and transport in unsaturated dutch soils

Microplastic pollution has become a growing concern in terrestrial ecosystems, with significant implications for environmental and human health. Understanding the fate and transport of microplastics in soil environment is crucial for effective mitigation strategies. This study investigates the dynamics of microplastic (Low-density polyethylene (LDPE), polybutylene adipate terephthalate (PBAT), and starch-based biodegradable plastic) transport in unsaturated soils under varying rainfall intensities and soil types, aiming to elucidate the factors influencing their behavior. Effluent samples were analyzed to measure microplastic transport, with microplastic balance analysis ensuring experimental accuracy. The setup replicated real-world flow conditions, providing insights into microplastic transport in unsaturated porous media. Microplastic balance analysis revealed high recovery factors (between 64 % and 104 %), indicating the reliability of the experimental approach. Microplastic transport varied significantly between sandy loam and loamy sand soils, with loamy sand soils exhibiting higher wash-off rates due to their unique properties. LDPE microplastics showed a higher tendency to detach from soil columns compared to PBAT and starch-based particles. Higher rainfall intensity in loamy sand soil columns resulted in an increased washout of LDPE, PBAT, and starch-based particles by 92 %, 144 %, and 85 %, respectively, compared to low rainfall intensity. In sandy loam soil, increased rainfall intensity resulted in a significantly higher washout of LDPE, PBAT, and starch-based particles with percentages of 93 %, 69 %, and 45 %, respectively. This underscores the important role of water flow in mobilizing microplastics within the soil matrix.

Recent achievements in nickel based electrochemical biorefinery of 5-hydroxymethylfurfural

The electrochemical conversion of biomass offers a sustainable approach for energy recycling and environmental protection. Specifically, the electro-oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid is notable for its potential to produce value-added products, including biodegradable plastics and other environmentally friendly materials. A critical factor in this process is the performance of the catalysts. Nickel-based catalysts have shown high efficiency and durability, primarily due to the formation of Ni-OOH active sites. This paper reviews recent advancements in the nickel-based electrocatalytic oxidation of HMF, including the use of Ni, Ni alloys, Ni oxides, Ni hydroxides, and other Ni complex, and discusses the underlying catalytic mechanisms. Additionally, it introduces the coupling reactions, various reactor designs and outlines future research directions, focusing on exploring reaction mechanisms, developing electrocatalysts, and practical applications of this technology.

Microbial consortia for multi-plastic waste biodegradation: selection and validation

The accumulation of plastic waste in the environment poses significant ecological and health risks. This study evaluates the effectiveness of microbial consortia in degrading various types of plastics, including low-density polyethylene (LDPE), low linear-density polyethylene (LLDPE), polyethylene terephthalate (PET) and polystyrene (PS). Qualitative enzyme assays for esterases and ligninases, which are related to plastic biodegradation, were conducted in five microbial strains. Four microbial consortia, combining bacterial and fungal strains, were assembled based on the enzyme profile of their components and evaluated for their ability to degrade both virgin and recycled plastics. The results showed that consortia C2 (Bacillus subtilis RBM2, Fusarium oxysporum RHM1, and Alternaria alternata RHM4) and C4 (Bacillus subtilis RBM2 and Pseudomonas alloputida REBP7) exhibited the highest biodegradation efficiency, particularly achieving significant weight loss in recycled LDPE, virgin LLDPE and recycled PET. The biodegradation was further confirmed by FTIR analysis, which revealed changes in the chemical composition and functional groups of the treated plastics, indicating microbial interaction and degradation. This study underscores the potential of microbial consortia in addressing plastic pollution, highlighting the importance of strategic consortia design based on enzymatic profiles and plastic colonization capabilities. These promising results suggest that further optimization of microbial consortia could offer a viable solution for large-scale plastic waste management.

Evaluation of Blended Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) Properties Containing Various 3HHx Monomers

Polyhydroxyalkanoate (PHA), specifically poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (P(3HB-co-3HHx), PHBHHx) with physical properties governed by the 3-hydroxyhexanoate (3HHx) mole fraction, is a promising bioplastic. Although engineered strains used to produce P(3HB-co-3HHx) with various 3HHx mole contents and fermentation techniques have been studied, mass production with specific 3HHx fractions and monomers depends on the batch, supply of substrates, and strains, resulting in the time-consuming development of strains and complex culture conditions for P(3HB-co-3HHx). To overcome these limitations, we blended poly(3-hydroxybutyrate) [(P(3HB), produced from C. necator H16] and P(3HB-co-20 mol%3HHx) [from C. necator 2668/pCB81] to prepare films with various 3HHx contents. We evaluated the molecular weight and physical, thermal, and mechanical properties of these films and confirmed the influence of the 3HHx monomer content on the mechanical and thermal properties as well as degradability of the blended P(3HB-co-3HHx) films containing various 3HHx mole fractions, similar to that of original microbial-based P(3HB-co-3HHx). Moreover, the degradation rate analyzed via Microbulbifer sp. was >76% at all blending ratios within 2 days, whereas a weaker effect of the 3HHx mole fraction of the blended polymer on degradation was observed. P(3HB-co-3HHx) could be produced via simple blending using abundantly produced P(3HB) and P(3HB-co-20mol%HHx), and the resulting copolymer is applicable as a biodegradable plastic.

Optimizing Thermoplastic Starch Film with Heteroscedastic Gaussian Processes in Bayesian Experimental Design Framework

The development of thermoplastic starch (TPS) films is crucial for fabricating sustainable and compostable plastics with desirable mechanical properties. However, traditional design of experiments (DOE) methods used in TPS development are often inefficient. They require extensive time and resources while frequently failing to identify optimal material formulations. As an alternative, adaptive experimental design methods based on Bayesian optimization (BO) principles have been recently proposed to streamline material development by iteratively refining experiments based on prior results. However, most implementations are not suited to manage the heteroscedastic noise inherently present in physical experiments. This work introduces a heteroscedastic Gaussian process (HGP) model within the BO framework to account for varying levels of uncertainty in the data, improve the accuracy of the predictions, and increase the overall experimental efficiency. The aim is to find the optimal TPS film composition that maximizes its elongation at break and tensile strength. To demonstrate the effectiveness of this approach, TPS films were prepared by mixing potato starch, distilled water, glycerol as a plasticizer, and acetic acid as a catalyst. After gelation, the mixture was degassed via centrifugation and molded into films, which were dried at room temperature. Tensile tests were conducted according to ASTM D638 standards. After five iterations and 30 experiments, the films containing 4.5 wt% plasticizer and 2.0 wt% starch exhibited the highest elongation at break (M = 96.7%, SD = 5.6%), while the films with 0.5 wt% plasticizer and 7.0 wt% starch demonstrated the highest tensile strength (M = 2.77 MPa, SD = 1.54 MPa). These results demonstrate the potential of the HGP model within a BO framework to improve material development efficiency and performance in TPS film and other potential material formulations.

Biobased Compostable Plastics End-of-Life: Environmental Assessment Including Carbon Footprint and Microplastic Impacts

In this paper, we examine how traditional life-cycle assessment (LCA) for bio-based and compostable plastics overlooks issues surrounding carbon sequestration and microplastic persistence. To outline biased comparisons drawn from these omitted environmental impacts, we provide, as an example, a comparative LCA for compostable biobased vs. non-compostable fossil-based materials. In doing so we (1) demonstrate the proper way to capture carbon footprints to make fair comparisons and (2) identify the overlooked issues of microplastics and the need for non-persistent alternatives. By ensuring accurate biogenic carbon capture, key contributors to CO2 evolution are properly identified, allowing well-informed changes to formulations that can reduce the environmental impact of greenhouse gas emissions. In a complimentary manner, we summarize the growing research surrounding microplastic persistence and toxicity. We highlight the fundamental ability and the growing number of studies that show that industrial composting can completely mineralize certified compostable materials. This mineralization exists as a viable solution to combat microplastic persistence, currently an absent impact category in LCA. In summary, we propose a new paradigm in which the value proposition of biobased materials can be accurately captured while highlighting compostables as a solution for the increasing microplastic accumulation in the environment.

Distinct exposure impact of non-degradable and biodegradable microplastics on freshwater microalgae (Chlorella pyrenoidosa): Implications for polylactic acid as a sustainable plastic alternative

Microplastics (MPs) are increasingly recognized as significant sources of harm to biota in various environments. However, the detrimental impacts of aged MPs with different structures and degradability remain poorly understood. In this study, aged MPs from polylactic acid (PLA), polyethylene (PE), and polystyrene (PS), representing biodegradable, aliphatic, and aromatic plastics, respectively, were prepared to examine their effects on microalgae (Chlorella pyrenoidosa). Structural and property analyses indicated the presence of aging and oxygen-containing functional groups on the surfaces of the MPs, which correlated with an increase in negative electrical charge (i.e., aged PLA > aged PE ≈ aged PS). Aged PLA MPs affected microalgae biomass, promoted protein synthesis, and elevated mild oxidative stress. In contrast, aged PE and PS MPs not only affected biomass, protein, and carbohydrate synthesis but also inhibited photosynthetic pigment production and activity, resulting in intracellular oxidative stress. Excitation-emission-matrix spectra analysis showed that PLA induced microalgae to secrete large amounts of humic acid-like extracellular polymers, whereas aged PE and aged PS groups contained only small amounts of them and proteins. This study addresses critical knowledge gaps in the toxicology of various aged MPs on microalgae and provides valuable insights into the potential of PLA as a sustainable alternative to conventional plastics in microalgae culture industry.

Status and Enhancement Techniques of Plastic Waste Degradation in the Environment: A Review

Plastic waste has been gradually accumulating in the environment due to rapid population growth and increasing consumer demand, posing threats to both the environment and human health. In this overview, we provide a comprehensive understanding of the degradation of plastics in real environments, such as soil, aquatic environment, landfill, and compost. Both conventional and biodegradable plastics exhibit limited degradation in real environments, except for biodegradable plastics during industrial composting with high thermophilic temperatures. Meanwhile, we also review techniques for enhanced degradation of plastics such as physical technologies (e.g., photocatalysis, mechanical degradation, and pyrolysis), chemical technologies (e.g., hydrolysis, alcoholysis, ammonia, strong oxidation, and supercritical fluids), and biotechnologies (e.g., microorganisms, microfauna, and microalgae). The future research directions for the enhancement of plastic degradation are also discussed, such as the establishment of equivalency standards, adoption of internal control techniques, the control of precise recycling of plastic products, and the ecotoxicology of their degradation products. Therefore, this review comprehensively summarizes the state of plastic degradation in real environments and proposes methods to improve plastic degradation, providing a theoretical basis for the future control and disposal of plastics.

Stimulation of Batch Mesophilic Anaerobic Digestion by Cellulose- and Polysaccharide-Derived Polymers in Landfill Leachates

The fate of biobased and biodegradable cellulose-derived plastics in landfills represents an important topic from economic and environmental points of view. Anaerobic digestion is a cost-effective waste-to-energy technology. The behaviour of six polymer types—that is, cellulose (C), cellulose acetate (CA), viscose (V), nanocellulose (NC), acetate textile (AT), and heteropolysaccharide pectin (P)—was studied under anaerobic batch mesophilic conditions in a landfill leachate for 147 days. The cumulative biogas production was as follows: C>V=CA>>AT>>NC=P. Metagenomic analysis revealed notable variations in the proportion of bacterial and archaeal domains with the highest archaeal abundance in the presence of CA (80.2%) and C (78.5%). At the end of digestion, cellulolytic, hydrolytic, and dehydrogenase activities were measured in the intact samples, as well as the liquid and solid fractions, under aerobic and anaerobic conditions. Cellulolytic activity in P was detected only in the pellet, while in NC, activity was mostly in the supernatant under both aerobic and anaerobic conditions. Scanning electron microscopy and confocal scanning laser microscopy showed a defragmentation and degradation of polymeric substrates as well as microbial colonisation. Based on the results, landfill leachate is appropriate for the anaerobic biodegradation of cellulose-derived polymers; however, the process is polymer specific.

Review on Biodegradable Aliphatic Polyesters: Development and Challenges.

Biodegradable polymers are gaining attention as alternatives to non-biodegradable plastics to address environmental issues. With the rising global demand for plastic products, the development of non-toxic, biodegradable plastics is a significant topic of research. Aliphatic polyester, the most common biodegradable polyester, is notable for its semi-crystalline structure and can be synthesized from fossil fuels, microbial fermentation, and plants. Due to great properties like being lightweight, biodegradable, biocompatible, and non-toxic, aliphatic polyesters are used in packaging, medical, agricultural, wearable devices, sensors, and textile applications. The biodegradation rate, crucial for biodegradable polymers, is discussed in this review as it is influenced by their structural properties and environmental conditions. This review discusses currently available biodegradable polyesters, their emerging applications, and the challenges in their commercialization. As research in this area grows, this review emphasizes the innovation in biodegradable aliphatic polyesters and their role in advancing environmental sustainability.