Advanced Strategies for Biodegradation of Plastic Polymers

This review employs country-level statistics pertaining to trash management. The contemporary global landscape is currently grappling with the complexities surrounding the effective management and remediation of the escalating volumes of plastic trash. As the population grows, there is a corresponding growth in the need for plastic and plastic items. These products are accountable for the generation of plastic, the accumulation of plastic trash, and the consequent environmental degradation. The assortment of plastic materials utilized in the manufacturing process of diverse important commodities, including medical gadgets, food packaging, and water bottles, is known to harbor detrimental compounds such as bisphenol, phthalates, and phenanthrene. Despite the various benefits of plastic, the global plastic industry is widely recognized as the source of significant environmental issues. The plastic tool presents a potential source of ambiguity regarding human exposure to hazardous substances. This assessment examines the present state of plastic waste management, focusing on key aspects such as landfilling, recycling, and incineration. The objective of this review is to examine the environmental and human health implications of plastic. In addition, we put out a potential resolution for effectively tracking the escalation of this burgeoning catastrophe.

In recent years, managing plastic garbage has become one of the most important environmental challenges. Conventional approaches that have been used to solve this issue have run across a number of obstacles that have reduced their efficacy in reducing plastic pollution. Inefficient recycling practices, the prevalence of single-use plastics, inadequate waste management infrastructure, difficulties with collection and sorting and the ongoing plastic waste discharged into the environment are now the biggest issues of conventional plastic waste management strategies that are highlighted in this paper. Looking ahead, future challenges in management of waste plastic are emerging as the problem continues to escalate. These difficulties include addressing the growing levels of waste plastic the fragmentation of plastic into hazardous microplastics and nanoplastics, the problem of pollution from plastic waste in the ocean, the creation and application of efficient policies and regulations and the promotion of international cooperation. In order to prevent plastic trash, communities, businesses, researchers, government agencies and individuals must work together. Preserving our planet for future generations requires concerted action to reduce plastic pollution and foster a cleaner and healthier environment for all living beings.

Polyethylene terephthalate (PET), which is a widely used synthetic polymer, poses significant environmental challenges due to its resistance to degradation. The traditional methods of recycling PET waste associated with burning and landfilling prove challenging, due to the detrimental impacts on both terrestrial and aquatic organisms. However, there are potentially effective ways to combat plastic pollution since a variety of microbial species, such as bacteria and fungi, have demonstrated the capacity to enzymatically break down PET. The enzyme responsible for PET degradation includes cutinases and PETases, providing insight into the biochemical processes that help break down this resistant polymer. The understanding of recent advancements and obstacles in PET biodegradation is essential for formulating enduring remedies to alleviate plastic pollution. The purpose of this chapter is to give the state of knowledge in the subject, directing future studies and assisting in the creation of environmentally appropriate PET waste management techniques.

The accumulation of plastic trash has been recognized as a significant environmental issue that impacts all forms of life, natural ecosystems, and the global economy. In these circumstances, it is crucial to prioritize the search for environmentally friendly alternatives, such as biodegradation instead of conventional disposal methods. Currently, there is limited knowledge regarding the mechanisms and effectiveness of plastic biodegradation. The purpose of this study is to provide a concise overview of the biodegradation processes of polyurethane (PU) and polyvinyl chloride (PVC), highlighting their significance in terms of environmental sustainability and waste management. Biodegradation, which harnesses the power of microbes and enzymes, holds immense promise in tackling the environmental issues associated with synthetic polymers. Biodegradation refers to the natural process by which microbes and enzymes break down organic matter. To effectively develop strategies for managing plastic waste and promoting sustainability, it is essential to have a thorough understanding of the mechanisms and factors that affect the biodegradation of polyurethane (PU) and polyvinyl chloride (PVC).

Use of plastics in the modern world has significantly increased and its persistent nature in an environment is still a major area of concern. Polystyrene (PS) is a synthetic derivative of plastic which is composed of styrene monomer units, and the presence of phenol group in the styrene monomer contributes to its stability. PS is used in large quantities as it is used for various packaging purposes in industry, but the major area of concern is its persistent nature in an environment. In addition to various physical and chemical techniques, the biodegradation method using microorganisms has also been employed. Numerous bacterial and fungal groups have been reported to possess potential to biodegrade PS. Microorganism-mediated PS degradation involves destruction of the core styrene structure which results in lowering molecular mass. Microorganism-mediated enzymatic degradation of PS is also one of the popular methods of biodegradation. Different techniques like scanning electron microscopy, transmission electron microscopy, biogas production, and determination of molar mass have been used to detect the biodegradation of PS.

Analytical methods for microplastics are essential for understanding and monitoring the degradation processes of these micromaterials, with some techniques even being able to identify them in living organisms. This chapter presents the fundamentals and applications of the main methods for the analysis of microplastics with a focus on degradation processes in environmental samples. Optical, electron, and atomic force microscopy methods are described. Spectrometric, thermal analysis, and chromatographic methods are also described. This wide variety of methods must be used together to obtain an integral qualitative and quantitative characterization. Hybrid techniques are of great interest as they show the best performance. Research on analytical methods for microplastics is still an area of opportunity, as there are still many practical limitations.

The discovery of the plastic-degrading microbes has unveiled new avenues for addressing the global plastic pollution crisis and possess the potential to revolutionize waste management practices. Microorganisms possess substantial potential to facilitate a more sustainable plastic economy through processes like biodegradation and enzymatic recycling of polymers. With the advent of gene editing tools, the field of molecular biology introduced innovative methods to precisely integrate foreign genes into specific genomic locations in various microorganisms, addressing the numerous challenges linked with existing methods. Recently, gene targeting methods involving zinc finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs), and clustered regularly interspaced short palindrome repeats (CRISPR) have gained prominence. This chapter concentrates on diverse strategies for production of degrading enzymes, synthetic biology, metabolic engineering, and gene targeting, which offer promising solutions to plastic waste management.

The impact of plastic waste on the environment is significant. Plastic waste can take hundreds of years to decompose, and it can cause harm to wildlife, marine ecosystems, and human health. From the Mariana Trench to Mt. Everest, there is virtually no place on Earth which is left untouched by plastic pollution. Plastic waste is now so ubiquitous in the natural environment that scientists have even suggested it could serve as a geological indicator of the Anthropocene era. The world is facing a global plastics crisis, and addressing the end of life of plastic products will not be enough to solve this global crisis. Plastic waste is a complex issue that requires a multifaceted approach. Governments, municipalities, businesses, and individuals all have a role to play in reducing plastic waste and managing it in an eco-friendly manner. The current trends and future perspectives of plastic waste management involve circular economy, 3R perspective, and innovative technologies. These approaches can help reduce the burden of plastic waste on the environment and pave the way for a more sustainable future.

The microplastics waste has a major adverse impact on oceans, lakes, seas, rivers, and coastal region, the environment seriously threatened by them. Microplastics (MPs) are particles of plastic with a diameter of <5 mm that can be found in both primary and secondary sources. Global research is being done on the growing issue of MP contamination in every aspect of our environment. A wide range of marine organisms are negatively impacted by microplastics, and studies show that these pollutants are known to move into the marine ecosystem through land-based activities like runoffs. Microplastic particles have been found dispersed extensively across Africa, South Asia, India, North America, and Europe. In this work, we discuss the sources, worldwide distribution, fate, and organisms’ life, especially in their food web and trophic levels. Additionally, international and national environmental association or organizations have advocated the mitigation techniques offered to decrease the impact of microplastics. Microplastics pollution in the environment can be greatly reduced by identifying the primary causes of the problem and raising public, private, and governmental knowledge of it through education. Additionally, being aware of the underlying behavioral mechanisms will help one comprehend the impacts on the marine ecosystems.

Electronic waste (e-waste) has become a significant global concern due to the rapid growth of consumer electronics and technological advancements. Among e-waste components, electronic plastic (e-plastic) is a major contributor, often composed of complex polymer blends with hazardous substances. The improper disposal of e-plastic poses severe environmental and health risks. This study aims to explore the current state of e-plastic waste management, focusing on its biodegradation potential as a sustainable solution. Several biodegradation methods, including natural and synthetic approaches, have been investigated. The role of microorganisms, enzymes, and bioactive compounds in breaking down e-plastic has been studied to understand the mechanisms behind biodegradation. Furthermore, the challenges associated with e-plastic biodegradation, such as the slow degradation rate, limited understanding of microbial communities involved, and potential toxic by-products during degradation, are also discussed. Additionally, the importance of eco-friendly design and sustainable materials selection in electronic manufacturing is emphasized to reduce the environmental impact of e-plastic waste. This research contributes to the growing body of knowledge on e-waste management and the need for sustainable disposal options for e-plastic. By understanding the biodegradation potential of e-plastic, policymakers, industry stakeholders, and researchers can work together to develop effective waste management strategies that prioritize environmental protection and resource conservation.

In our current lifestyle, plastics place a very important role; therefore, its gathering in the environment is major alarms that harm the human health. Petroleum-derived plastics such as PE, PET, PU, PS, PP, and PVC are awfully recalcitrant to natural biodegradation pathways. Large number microorganisms have the capacity to degrade petro-polymers under natural as well as lab conditions which have been investigated by different scientists. The enzymes produced by different microbes have been genetically engineered. The polymer biodegradation rate depends on various factors like molecular weights, chemical structures, and degrees of crystallinity. These are bulky molecules having crystals as well as irregular groups that provide hardness and flexibility to the polymers. Polyethylenes (95%) are rigid, highly crystalline polymers with a limited capacity to oppose impact. Crystallinity of a polymer (30–50%) in plastic is a main cause of slow microbial degradation. The microbial degradation as well as enzymatic degradation occurs via enzyme adsorption on the surface of polymer, followed by hydro-bond peroxidation and hydrolysis. The petro-plastic disintegration or depolymerization into polymer monomers for different purposes like recycling or converting waste plastics into higher-value by-products is considered as a promising strategy. Finally, plastic degradation can be measured by applying different techniques like SEM, TEM, FTIR, TGA, UV spectroscopy, DSC, HPLC, etc. The purpose of this section is to sketch the different categories of plastic, their impact on environment, the impact of microbes, or their enzymes toward the degradability of synthetic plastics to clean up the environment.

Biodegradation greatly depends on microorganisms, such as bacteria, algae, and fungi, to degrade polymers through their metabolic activity under aerobic or anaerobic conditions. Synthetic plastics are greatly linked to our modern lifestyle; therefore, their accumulation in the environment is a major issue and of great concern to the environment and humans. Products such as polyvinylchloride, polystyrene, polyurethane, polyethylene, polypropylene, etc. are resistant to biodegradation pathways under natural conditions. Polymer-degrading microbes have been isolated and identified under in vitro conditions. Microbial degradation and depolymerization of waste plastics into higher-value bioproducts, such as biodegradable polymers, have been a great strategy. This chapter aims to provide valuable information pertaining to the microbial degradation of polymers through their enzymatic activity.

In this chapter, environmental policy impact is discussed considering biodegradable plastic polymers. An attempt is made to study various elements, namely, plastic/bioplastic biodegradation; biodegradation of herbicides, pesticides, and insecticides; agricultural crop residue biodegradation; biodegradation of oil; air pollution due to biodegradation; and water pollution due to biodegradable plastics. The current research is analyzed through several initiatives adopted by governments and nonprofit organizations that increase the usage of biodegradable plastics. The effects of biodegradable plastics on the ecosystem are also explored in current research. The article documented the pros and downsides of using biodegradable polymers in an effort to lessen plastic waste in the environment. Finally, it is concluded that for a sustainable future, there is the need of well-designed regulations and a thorough knowledge of the effects of biodegradable plastics.

The chapter provides a comprehensive overview of the synthesis and significance of bioplastics as eco-friendly alternatives to conventional petro-based plastics. Petroleum-based plastics are linked to numerous environmental issues, such as pollution, persisting in both terrestrial and marine habitats, and greenhouse gas emissions. The escalating environmental concerns associated with traditional plastics have led to an urgent need for sustainable alternatives. Bioplastics, derived from renewable resources such as plants, microorganisms, or agricultural by-products, have emerged as a promising solution to mitigate the ecological impact of conventional plastics. Beginning with an introduction to the historical development and widespread use of plastics, the narrative delves into the environmental challenges posed by plastic pollution. The chapter emphasizes the urgent need for sustainable alternatives, leading to the exploration of bioplastics as a viable solution. The focus then shifts to the definition and classification of bioplastics based on their biobased or biodegradable properties.

Plastic waste production is a significant global environmental issue that poses a threat to the health and survival of living organisms. The responsible management of these plastics is a significant challenge in the twenty-first century. Various plastic polymers have been developed over the past 150 years, replacing traditional materials like metal, glass, and wood in different applications. However, the nonreactive and nondegradable nature of plastic has resulted in a massive increase in plastic waste generation, causing serious environmental problems. Plastic waste accumulates in landfills, contaminates the soil, and contributes to increased greenhouse gas emissions. These are some of the harmful effects observed. It is essential to address this ecological problem due to the negative impact of plastic pollution on terrestrial ecosystems. Conventional methods of plastic waste disposal, such as incineration, landfilling, and recycling, have environmental drawbacks. Some synthetic plastics, such as polyethylene terephthalate, polyurethane, polystyrene, polypropylene, and polyvinyl chloride, have chemical structures, molecular weights, and degrees of crystallinity that make them highly resistant to natural biodegradation processes. Enzymes produced by microbes have long been considered a potential biological agent for the biodegradation of plastics; these enzymes can facilitate the hydrolysis or oxidation of polymer bonds, resulting in the formation of less complex and less harmful chemicals. Numerous microorganisms, particularly fungi and bacteria, have been isolated and characterized for their ability to degrade plastics under laboratory conditions. Some of the enzymes involved in plastic biodegradation have been identified and cloned, and their mechanisms of action have been elucidated. Furthermore, genetic engineering and protein engineering techniques have been employed to modify and enhance the activity, specificity, and stability of these enzymes. This chapter provides an overview of the current knowledge on the role of microbial enzymes and their modifications for plastic biodegradation and discusses the challenges and opportunities for the role of microbial enzymes and their modifications for plastic biodegradation.

The worldwide annual consumption of plastic stands at an approximate of 450 million metric tons, which is almost 57 kg per person. Out of this yearly consumption, around 350 million metric tons are generated as waste, of which an estimate of 80 million metric tons falls under the category of mishandled plastic dump becoming the cause of plastic-generated pollution or plastic pollution. This plastic pollution costs both social and environmental aspects of economies – a minimum of USD 300 billion per annum. Hence, there is a need to develop eco-friendly technologies working toward recycling methods costing much cheaper than present alternatives, increase in secondary plastic usage, and managing single-use plastic pollutions.