Aug 2026· Preparative Biochemistry & Biotechnology· pp.
1-21
· 0 citations· 117 references
Medicine
TL;DR
Reframing plastic degradation as a multi-scale, designable system rather than a single-enzyme process highlights opportunities for coupling protein engineering with controlled deployment, including biofilm-based localization and metabolic pathway integration, to enable more effective and environmentally relevant microplastic remediation.
Abstract
Microplastic pollution is a pervasive global challenge, with millions of tons of plastic entering terrestrial and aquatic ecosystems each year and persisting across diverse environmental compartments. Conventional physical and chemical remediation strategies remain energy-intensive and inefficient, highlighting the need for scalable biological alternatives. Here, we synthesize recent advances in lipase-mediated degradation of ester-bond-containing plastics and propose a unifying framework for programmable biodegradation, in which enzyme activity, substrate accessibility, and downstream metabolism are systematically coordinated. Lipases (EC 3.1.1.3) can hydrolyze synthetic polyesters, including polyethylene terephthalate (PET), polyurethane (PU), polylactide (PLA), and polycaprolactone (PCL), but their performance is constrained by polymer crystallinity, limited environmental stability, and restricted substrate specificity. Integrating insights from multi-omics discovery, artificial intelligence-guided enzyme engineering, and systems-level design reveals emerging strategies to enhance catalytic efficiency and environmental robustness. Although engineered enzyme systems can achieve high depolymerization and monomer recovery under controlled conditions, translation to real environments remains limited by diffusion constraints, enzyme inactivation, and regulatory considerations. Reframing plastic degradation as a multi-scale, designable system rather than a single-enzyme process highlights opportunities for coupling protein engineering with controlled deployment, including biofilm-based localization and metabolic pathway integration, to enable more effective and environmentally relevant microplastic remediation.
Oil pollution remains a persistent global environmental challenge due to the recalcitrance and toxicity of lipid-rich contaminants in terrestrial and aquatic ecosystems. Bacterial lipases (EC 3.1.1.3) play a pivotal role in the initial stages of bioremediation by catalysing the hydrolysis of complex lipids into more bioavailable intermediates, thereby facilitating downstream microbial degradation and mineralisation. This review critically examines the mechanistic basis of lipase-mediated hydrocarbon degradation, with emphasis on enzyme structure–function relationships, catalytic pathways, and regulation under environmentally relevant conditions. In addition to conventional applications in soil and wastewater bioremediation, emerging strategies involving immobilised enzymes, microbial consortia, and waste-derived substrates are evaluated for their effectiveness and scalability. Attention is given to advances in molecular and omics approaches, including metagenomics, transcriptomics, and proteomics, which have expanded the discovery of novel lipases but remain limited in their ability to predict in situ functionality. The review highlights the growing role of protein engineering and artificial intelligence in tailoring lipase properties; however, it also critically assesses current limitations, including insufficient experimental validation and challenges in translating computational predictions to complex environmental systems. Furthermore, integrating multi-omics data into quantitative and predictive frameworks is identified as a key future direction for improving bioremediation efficiency. Despite significant progress, major gaps persist in linking enzyme activity to real-world degradation performance and in developing standardized, scalable approaches. This review therefore provides a comprehensive and critical synthesis of current knowledge while identifying strategic research priorities required to advance bacterial lipases as robust tools for sustainable bioremediation of lipid-based pollutants.
A. Baruwa, Nyashadzashe P. Masvingwe, G. Kana et al.· Applied Sciences· 0 citations
Pollution by emerging contaminants like microplastic is one of the major environmental concerns. Microplastics have become ubiquitous anthropogenic pollutants of aquatic, terrestrial and atmospheric ecosystems, and can generate considerable ecological and health-related risks. Conventional remediation regimes are widely ineffective, due to the physicochemical recalcitrance of polymer matrices. Recent advances in microbial biotechnology have revealed several contrasting microbial taxa and enzyme systems, which can convert or mineralize synthetic polymers through a variety of pathways of complex biochemistry. This review summarizes the current understanding of microbial–polymer interactions, including surface colonization, biofilm-mediated depolymerization, and intracellular uptake of degradation intermediates. It also discusses recent developments in enzyme engineering, strain optimization employing the CRISPR method, and synthetic biology approaches improving catabolic efficiency. The advent of a variety of multi-omics technologies of metagenomics, transcriptomics, and metabolomics has enabled the characterization of novel hydrolases and oxidoreductases with a high potential catalytic efficiency. Advances in nanobiocatalysis, enzyme immobilization, and bioreactor technology improve the scale-up of these processes. Related molecular developments and environmental applications will promote the application of microbial biotechnology as a selective and sustainable tool for the mitigation of microplastic accumulation and the development of a circular bioeconomy that interacts positively with ecosystem resilience.
Polyurethanes represent one of the most widely produced synthetic polymers, with applications in construction, automotive, consumer goods, and biomedical sectors. Their extensive use, combined with high durability, complex formulations, and insufficient end-of-life management, has resulted in significant environmental accumulation and recycling challenges. Conventional disposal routes are associated with slow degradation rates and the release of hazardous byproducts, while chemical recycling methods are often constrained by high energy demands and limited economic viability. Enzymatic biodegradation has emerged as a sustainable alternative due to its lower energy requirements and reduced environmental impact. However, resistance of polyurethanes to biological attack, arising from their segmented structure, high crystallinity, cross-linked networks, and widespread use of additives, limits enzymatic efficiency. To date, most reported polyurethane-degrading enzymes exhibit esterolytic activity and are primarily effective against polyester-based polyurethanes, while efficient enzymatic cleavage of urethane bonds, particularly in polyether-based systems, remains limited. Recent studies indicate that pretreatment strategies can enhance polyurethane susceptibility to enzymatic degradation, although systematic evaluation remains limited. To address the limitations of standalone recycling methods, this review provides a systematic, comparative analysis of pretreatment technologies aimed at breaking down complex polyurethane networks to enhance enzymatic degradation. We examine how different pretreatments alter polyurethane structure and improve enzymatic accessibility, and identify key challenges, knowledge gaps, and future research directions. Pretreatment is therefore needed for efficient enzymatic polyurethane recycling, and chemical depolymerization combined with enzymatic hydrolysis is currently the most effective approach.
O. Todorović, L. Golubović, Đ. Katnić et al.· Bioresource Technology· 0 citations
Plasticizers added to plastics are toxic, endocrine-disrupting chemicals that may leach into the environment. Chemical and microbial degradation were reported to degrade the plasticizers. Most chemical methods operate at high temperature and pressure (energy-intensive conditions), whereas microbial hydrolases suffer from issues such as enzyme denaturation and low substrate loading. Therefore, the development of artificial biomimetic hydrolase is crucial. Microbial hydrolases utilize the proximity and proper orientation of the reactants (binding pocket) to catalyze hydrolysis in aqueous media. Inspired by nature, a novel membrane transport-inspired biomimetic approach (nanozyme) was developed to hydrolyze stable esters of aromatic acids (plasticizers) at physiological pH. This approach utilized choline- and thiocholine-based cationic micellar nanostructures to achieve high plasticizer loading in water. The nanozymes were activated by electrochemical stimulation via water splitting near the cathode, and the proximity of the reactants (plasticiser, nucleophilic catalyst, and transiently high pH) was established. Mechanistic investigations suggest that the perturbation of the pKas of hydroxy/thiol groups of nucleophilic choline or thio-choline moieties assisted the nucleophilic attack by the catalyst amphiphiles (NLC, NLTC) to hydrolyze the stable plasticiser esters in the green aqueous medium.
Raki Mandal, Sanu Sar, Trisha Maiti et al.· Chemistry - An Asian Journal· 0 citations
Polybutylene adipate terephthalate (PBAT) is prone to incomplete degradation, leading to environmental pollution and carbon resource waste. Biodegradation and valorization of waste plastics are essential for addressing plastic pollution and promoting a circular economy. Enzymatic degradation offers advantages, but free enzymes suffer from low stability and poor recyclability. Here, surface display technology was used to construct a cutinase Tfcut-DM display system in Escherichia coli BL21(DE3). The results showed that surface display significantly enhanced the stability and reusability of Tfcut-DM. Compared with free enzymes, its thermostability and pH stability increased by 11.9-fold and 42.1-fold, respectively, and approximately 80% of initial activity was retained after seven reuse cycles. Under optimized conditions, the surface-displayed strain released 255.9 µM of terephthalic acid (TPA) from PBAT films over 5 days, with near-complete degradation. To enable TPA valorization , the tph operon was introduced to C. necator H16 (CnH16-tph) for TPA-to-PHB conversion. A co-culture system comprising the surface-displayed strain and CnH16-tph was established for proof-of-concept one-pot conversion of PBAT to PHB. PHB accumulation is indirectly attributed to the TPA derived from PBAT degradation. Under optimized conditions, the maximum PHB yield reached 0.91 g/L. While isotopic tracing would be required for definitive carbon flux assignment, this indirect evidence strongly suggests the successful conversion of PBAT-derived TPA to PHB. This study provides a novel approach for the green degradation and resource utilization of waste PBAT, facilitating the recycling of discarded resources.
Jiali Liu, Jie Yang, Xin Wang et al.· Bioresource Technology· 0 citations
The bioplastics field has oriented around industrial compostability as the primary biodegradation target. We argue this constitutes a regime mismatch: most plastic waste enters landfills - anaerobic, ambient-temperature environments in which poly(lactic acid) (PLA) and the majority of certified compostable bioplastics exhibit negligible degradation. Accepting landfill-active biodegradability as the correct constraint immediately reorders the candidate space. We conduct a systematic analysis across molecule class, production organism, processing architecture, and degradation mechanism, identifying three primary microbial production architectures with credible paths to the $1-2/kg commodity cost target: (1) Halomonas bluephagenesis Next-Generation Industrial Biotechnology (NGIB) for polyhydroxyalkanoate (PHA) - the most industrially-validated architecture, with demonstrated 149g/L cell dry weight at 82% PHA in 5,000-L continuous non-sterile fermentation; (2) poly(γ-glutamic acid) (γ-PGA) / chitosan polyelectrolyte composites - extracellular production from Bacillus subtilis, water-phase processing without organic solvents, thermoplastic behavior when dry, and rapid protease-mediated landfill degradation, a combination not previously proposed as an integrated commodity plastic production strategy; and (3) a beetle cuticle-mimetic composite produced entirely from microbial sources - presented as a biomimetic materials hypothesis pending experimental validation. Two orthogonal strategies - bacterial cellulose pellicle production and viral capsid protein nanofillers - are evaluated as secondary approaches. A claim-status framework distinguishing evidence levels across all architectures is provided.
Christopher Childers· Journal of Biotechnology· 0 citations