Search Results (101)

The textile industry generates dye-containing wastewater characterized by intense coloration, high salinity, elevated oxygen demand, and recalcitrant pollutants. Although conventional treatment technologies can remove color and reduce organic load, decolorization alone does not guarantee detoxification because toxic transformation products may persist or be generated during incomplete degradation. This review emphasizes the synergistic interaction between oxidative and reductive enzymes and microorganisms as a promising strategy for promoting extensive pollutant transformation and potentially enhancing mineralization. Particular attention is given to the complementary roles of laccases (LAC), azoreductases (AZOR), ligninolytic peroxidases, bacteria, fungi, and microbial consortia in sequential degradation pathways that can improve detoxification efficiency. Mechanisms including azo bond cleavage, aromatic amine transformation, and subsequent microbial degradation are discussed to demonstrate how integrated systems can overcome the limitations of enzyme- or microorganism-based treatments alone and may facilitate complete pollutant removal under appropriate conditions. The review also explores biomass-derived biocatalysts produced through solid-state fermentation of agro-industrial residues, demonstrating opportunities to integrate wastewater remediation with biomass valorization and circular bioeconomy principles. Finally, operational challenges, toxicity assessment, reactor design, enzyme immobilization, scale-up, and techno-economic considerations are discussed, and future research priorities are identified to support the development of sustainable and industrially applicable enzymatic–microbial detoxification technologies. Full article

Microbial biodegradation represents a promising approach to addressing global plastic pollution, yet the metabolic pathways and environmental origins of polymer-degrading microorganisms remain incompletely characterized. This review synthesizes current knowledge on biodegradation mechanisms across major polymer classes and identifies key environmental reservoirs harboring native plastic-degrading microbiota. Biodegradation pathways differ fundamentally according to polymer chemistry. Polyesters such as PET undergo hydrolytic cleavage by PETases and MHETases, releasing terephthalic acid and ethylene glycol for assimilation via the β-ketoadipate pathway and the TCA cycle. Biodegradable polyesters (PLA, PBAT, PHAs, PCL) are similarly hydrolyzed by cutinases, lipases, and depolymerases. In contrast, polyolefins (PE, PP) and polystyrene lack hydrolyzable bonds and require oxidative attack by laccases, peroxidases, and alkane monooxygenases, followed by β-oxidation to acetyl-CoA. Three principal environmental reservoirs supply plastic-degrading microorganisms: contaminated ecosystems including landfills and the plastisphere; soil microbiota contributing ligninolytic fungi and actinomycetes; and compost environments yielding thermostable enzymes such as leaf-branch compost cutinase. Across all environments, microbial consortia demonstrate superior degradation efficiency compared to single-species cultures, reflecting the enzymatic complexity required for complete polymer mineralization. Understanding these pathways and their environmental origins provides a foundation for biological plastic waste management strategies. Full article

Brewer’s spent grain (BSG) is an abundant lignocellulosic by-product whose valorization can support circular bioeconomy strategies. This study evaluated BSG bioconversion by Aspergillus oryzae ATCC 10124 under solid-state fermentation (SSF) to produce lignocellulolytic enzymes and release second-generation (2G) sugars relevant to biorefinery applications. SSF was monitored over 0–10 days, and FPase, endo-cellulase, β-glucosidase, xylanase, mannanase, amylase, and ligninolytic enzyme activities were quantified. Enzymatic crude extracts were further assessed in SDS-PAGE analysis. Glucose, cellobiose, xylose and arabinose release and consumption were tracked throughout fermentation, and substrate transformation was supported by FTIR. The secretome exhibited a predominantly hydrolytic profile, with maximal hemicellulolytic and cellulolytic activity around days 2–4, as well as sustained amylase activity. Ligninolytic activity was not detected. Sugar profiles indicated rapid early hydrolysis of glucose, followed by progressive pentose release. The stabilization and decline were consistent with fungal uptake. Changes in the carbohydrate fingerprint and SDS–PAGE banding supported structural polysaccharide remodeling and hydrolytic protein secretion. Thus, this SSF platform confirmed certain potential for low-cost cellulolytic and hemicellulolytic enzyme generation. However, because sugar accumulation was temporary and followed by consumption, this system is best interpreted as a biological pretreatment and enzyme-generation step that supports subsequent downstream valorization. Full article

The widespread utilization of synthetic dyes within the textile industry, driven by their chemical recalcitrance and diverse chromatic spectra, constitutes a significant global environmental challenge. Improper discharge of these highly stable effluents into natural water bodies leads to severe ecological imbalances, affecting aquatic life and soil integrity while posing indirect risks to human health due to their mutagenic potential. Conventional physicochemical treatment methods are often hindered by prohibitive operational costs and the frequent generation of hazardous secondary pollutants. Consequently, there is an urgent demand for sustainable biotechnological alternatives to mitigate these industrial impacts. Bioremediation, specifically using white-rot fungi, represents a robust and eco-friendly strategy for the degradation of complex aromatic structures. Species such as Trametes versicolor, Pleurotus ostreatus, and Phanerochaete chrysosporium utilize a specialized extracellular enzymatic complex to mineralize toxic compounds effectively. Here we review the ligninolytic capacity of white-rot fungi and their specialized enzymatic systems for environmental sustainability. The primary points are: (i) the biochemical mechanisms of the ligninolytic system of laccases and peroxidases during dye degradation; (ii) the influence of operational parameters such as pH, temperature, and nutrient availability on fungal metabolic efficiency; (iii) the diverse environmental applications of these microorganisms in treating real textile effluents; (iv) the current biotechnological challenges, including maintaining enzymatic stability in non-sterile industrial environments; and (v) the future perspectives for scaling up fungal treatment systems from laboratory research to large-scale industrial implementation. Full article

Lignocellulosic biomass is an abundant renewable resource, yet its effective utilization remains limited due to its structural recalcitrance, primarily attributed to lignin. While aerobic lignin-degrading microorganisms, particularly fungi, have been extensively studied, much less is known about bacteria capable of lignin depolymerization under low-oxygen conditions. This study focused on the isolation and evaluation of native anaerobic bacterial cultures capable of degrading lignin-derived compounds to enhance biogas production. Soil samples from decaying vegetation and olive mill wastewater were used as microbial sources. Enriched cultures were developed anaerobically using kraft lignin and p-coumaric acid as sole carbon sources. Twelve pure bacterial strains were isolated and screened for their ligninolytic activity. All strains were able to degrade p-coumaric, with the highest biomass concentration reaching 387 mg L⁻¹ and maximum substrate consumption rate at 438 mg L⁻¹ d⁻¹. When kraft lignin was used as sole carbon source, 9 out of 12 strains showed growth, with a maximum of 55 mg L⁻¹ over 11 days. Enzyme activity assays confirmed the production of lignin peroxidase and laccase, with highest values at 2.10 and 0.15 U mL⁻¹, respectively, even under conditions of limited oxygen. The enriched cultures were applied in biomethane potential (BMP) batch tests, resulting in increased methane production. The best performing culture resulted in a bioaugmentation percentage of 174% compared with control. These findings suggest that native ligninolytic bacteria can serve as promising bioaugmentation agents in anaerobic digestion of lignocellulosic waste. Full article

Synthetic azo dyes are widely used in the textile industry; however, their use often poses environmental challenges. Here, we characterized the compost bacterium Bacillus subtilis strain CKCC for the decolorization of various azo dyes, including Congo Red, Reactive Black 5, Reactive Green 19, Reactive Red 120, and Reactive Blue 4. The application of strain CKCC exhibited high decolorization efficiency by utilizing various extracellular enzymes, including azoreductase and ligninolytic enzymes such as laccase, lignin peroxidase, and manganese peroxidase, which are essential for the decolorization of azo dyes. Fourier transform infrared spectroscopy (FTIR) analysis revealed structural changes during decolorization, consistent with the degradation of key functional groups. This transformation was attributed to the cleavage of azo linkages by azoreductase, with ligninolytic enzymes functioning on phenolic and aromatic moieties. While FTIR confirmed these structural changes, our findings only provided insights at the functional-group level, and the presence or absence of specific decolorized metabolites, such as aromatic amines, requires additional analytical techniques. In this study, the phytotoxic metabolites positively affected the germination and growth of Vigna radiata, confirming that decolorization using strain CKCC significantly reduced the toxic properties of the metabolites produced during dye decolorization. Hence, our isolated strain CKCC offers a potentially effective and environmentally sustainable method for treating azo-dye effluent in the textile industry. Full article

Fungi have emerged as versatile biotechnological platforms for addressing environmental challenges with potential co-benefits for human health. Among them, Pleurotus ostreatus stands out for its ligninolytic enzyme systems (notably laccases), capacity to valorize lignocellulosic residues, and ability to form functional mycelial materials. We conducted an evidence-mapped review, based on a bibliometric analysis of the Scopus corpus (2001–2025; 2085 records), to characterize research fronts and practical opportunities in environmental remediation and sustainable bioprocesses involving P. ostreatus. The mapped literature shows sustained growth and global engagement, with prominent themes in: (a) oxidative transformation of phenolic compounds, dyes and polycyclic aromatic hydrocarbons; (b) biodegradation/bioconversion of agro-industrial residues into value-added products; and (c) development of bio-based materials and processes aligned with the circular bioeconomy. We synthesize how these strands translate to real-world contexts, reducing contaminant loads, closing nutrient loops, and enabling low-cost processes that may indirectly reduce exposure-related risks. Key translational gaps persist: standardization of environmental endpoints, scale-up from laboratory to field, performance in complex matrices, life-cycle impacts and cost, ecotoxicological safety, and long-term monitoring. A practical agenda was proposed that prioritizes field-scale demonstrations with harmonized protocols, integration of life-cycle assessment and cost metrics, data sharing, and One Health frameworks linking environmental gains with plausible health co-benefits. In conclusion, P. ostreatus is a tractable platform organism for sustainable remediation and bio-manufacturing. This evidence map clarifies where the field is mature and where focused effort can accelerate the impact of future research. Full article

Trametes polyzona is a white-rot basidiomycete with increasing relevance in environmental biotechnology due to its ligninolytic enzymes, biodegradation capacity, and versatile metabolic responses to diverse substrates. To provide an integrated and updated understanding of its biotechnological potential, we conducted a systematic review following PRISMA guidelines. A total of 46 studies published between 1991 and 2024 were analyzed, covering enzymatic production profiles, degradation of xenobiotics, extraction of bioactive metabolites, and experimental conditions influencing performance. Across the literature, T. polyzona consistently exhibits high ligninolytic activity, including laccase specific activities reported up to 1637 U/mg, together with efficient transformation of dyes, pesticides, and phenolic pollutants, and promising antioxidant and antimicrobial properties. However, substantial methodological heterogeneity was identified, particularly in strain characterization, fermentation parameters, and analytical approaches used to quantify enzymatic and biodegradation outcomes. These inconsistencies limit cross-study comparability and hinder process standardization. This review integrates current evidence; highlights critical gaps, such as limited ecotoxicological assessment of degradation products and scarce multi-omics characterization; and identifies key opportunities for process optimization in submerged/solid-state fermentation, bioreactor scaling, and the valorization of fungal metabolites. Overall, T. polyzona remains an underutilized resource with distinct advantages for applied mycology, environmental remediation, and industrial biotechnology. Full article

The white-rot fungus Irpex lacteus is recognized for its strong ligninolytic and polysaccharide-degrading capacity, but the key advantages in degrading lignocellulose and the regulation of its enzyme systems remain poorly understood. In this study, we identified a rich repertoire of carbohydrate-active enzymes in the genome of I. lacteus QJ. Relative to other white-rot fungi, an expanded glycoside hydrolase gene family in I. lacteus QJ suggesting strong potential for lignocellulose degradation. When I. lacteus QJ was cultivated on glucose or wheat straw for 4 and 8 days, wheat straw strongly induced carbohydrate-active enzyme genes on day 4, while ligninolytic enzyme genes exhibited delayed upregulation on day 8. The cellobiose dehydrogenase plays an important role in the degradation processes. Its expression pattern is consistent with that of cellulase, and it can support peroxidase activity by providing H₂O₂. These findings reveal temporal coordination between polysaccharide- and lignin-degrading enzymes, providing new theoretical ideas for the application of I. lacteus during the degradation process. Our results not only improve the mechanistic understanding of fungal lignocellulose deconstruction but also inform strategies to enhance biological pretreatment of agricultural residues for biorefinery applications. Full article

Plant-based residues generated within the agri-food system represent an abundant resource with significant potential for sustainable valorization. However, they are still underutilized and place a substantial burden on the environment and climate. This review discusses research trends over the past decade, combining bibliometric analysis with an overview of emerging technologies applied to the processing of residues generated from conventional crops and medicinal and aromatic plants. The bibliometric analysis reveals main valorization pathways, ranging from energy production to recovery of high-value bioactive compounds. Recent advances in this field are discussed in detail, with emphasis on low-energy and non-thermal processing (ultrasound, microwave, cold plasma), green solvents (natural deep eutectic solvents, bio-based solvents), biological pretreatments (with ligninolytic microorganisms and enzymes), thermochemical technologies (hydrothermal carbonization, pyrolysis), and emerging cascade strategies applied for multi-product recovery. Published research proves that these approaches have a great potential for sustainable valorization, while process optimization and economic feasibility remain a challenge at industrial scales for wider adoption. By providing an integrated perspective on diverse types of plant-based residues, this review highlights the importance of developing cascade and circular processing strategies, which align with global sustainability goals and encourage innovation in bio-based industries. New knowledge and advances in this field are highly required and will further help the transition of the current agri-food system towards greater circularity and sustainability. Full article

Lignin, the most abundant aromatic biopolymer, represents a key renewable feedstock for sustainable biorefineries, yet its structural complexity poses a formidable challenge for enzymatic degradation. While ligninolytic enzymes such as laccases (LACs), lignin peroxidases (LiPs), and manganese peroxidases (MnPs) exhibit remarkable catalytic versatility, the molecular mechanisms underlying their ability to balance substrate specificity and structural flexibility remain unresolved. Here, we employed all-atom molecular dynamics (MD) simulations and virtual mutagenesis to dissect the dynamic interactions between these enzymes and lignin model compound (β-O-4-linked H-type dimers). Our simulations revealed a dual recognition mechanism in which polar residues (such as Asp, Glu, Arg and His) formed hydrogen bonds with hydroxyl and keto groups near catalytic cleavage sites, ensuring precise alignment for bond scission, while aromatic residues stabilized diverse lignin conformations via hydrophobic interactions with conserved aromatic rings. Conformational dynamics of active-site residues enabled adaptive adjustments to substrate heterogeneity, reconciling enzymatic specificity with structural promiscuity. Virtual mutation experiments further demonstrated that aromatic residues were indispensable for binding stability, whereas polar residues dictated cleavage-site selectivity. These findings provide atomic-scale insights into the catalytic mechanism of ligninolytic enzymes, with implications in the rational design of superior biocatalyst for lignin biorefineries. Full article

Background/Objectives: Wastewaters containing antibiotics pose risks to human health and soil ecosystems. In this study, the white-rot fungus Coriolopsis gallica (a basidiomycete exhibiting high laccase production) was used for the biotransformation of three antibiotics (50 mg L⁻¹): tetracycline, chloramphenicol, and sulfanilamide. Methods: The biotransformation process was investigated in liquid and solid media using high-performance liquid chromatography (HPLC) and the bacterial growth inhibition agar well diffusion method, respectively. Results: Among the three antibiotics tested, tetracycline showed the highest biotransformation efficiency, achieving a 100% removal rate in the liquid medium and a 100% decrease in the growth inhibition of Escherichia coli in the solid medium. Chloramphenicol and sulfanilamide were partially removed (20% and 16%, respectively) after 12 days of treatment in more than one step without the loss of their antibacterial activities. The presence of these antibiotics in the culture medium of C. gallica enhanced laccase activity, indicating that this ligninolytic enzyme might participate in the biotransformation process. Conclusions: Thus, the results reported in this article extend our knowledge of the catalytic potential of C. gallica and give further perspectives for its application in the biodegradation of antibiotics. To the best of our knowledge, this is the first study wherein C. gallica was used for the treatment of tetracycline, chloramphenicol, and sulfanilamide. Full article

Petroleum-contaminated soils are a major environmental concern worldwide. In Ecuador, extensive oil spills in the Amazon have led to widespread hydrocarbon pollution, threatening ecosystems and posing health risks to nearby communities. Conventional remediation techniques are resource-intensive and may render soil unsuitable for future use. In contrast, mycoremediation—using fungi to degrade toxic contaminants—offers a sustainable alternative. White-rot fungi, known for their ligninolytic enzyme systems such as laccases and peroxidases, are capable of degrading a wide range of organic pollutants, including petroleum hydrocarbons. This study assessed the enzymatic activity of 16 fungal strains from the phyla Ascomycota and Basidiomycota isolated in the Ecuadorian Amazon. Plate-based screening and quantitative laccase activity assays confirmed positive enzymatic activity in all strains. The five strains with the highest enzymatic activity were Ganoderma cf. parvulum QCAM7791, Trametes menziesii QCAM7783, Trametes menziesii QCAM7788, Trametes menziesii QCAM7790, and Trametes meyenii QCAM7785, which were selected for a 60-day soil microcosm experiment under controlled laboratory conditions. These strains removed over 96% of total petroleum hydrocarbons from contaminated soil, demonstrating high biodegradation efficiency. These results highlight the promise of native fungal strains as bioremediation agents for petroleum-contaminated soils. Further studies should focus on evaluating their performance under field conditions and their potential integration into large-scale remediation strategies. Full article

Alperujo, a solid by-product from the two-phase olive oil extraction process, poses significant environmental challenges due to its high organic load, phytotoxicity, and phenolic content. At the same time, it represents a promising feedstock for recovering value-added compounds such as phenols and volatile fatty acids (VFAs). When used as a substrate for white rot fungi (WRF), it also produces ligninolytic enzymes. This study explores the use of two native WRF, Anthracophyllum discolor and Stereum hirsutum, for the biotransformation of alperujo under solid-state fermentation conditions, with and without supplementation of copper and manganese, two cofactors known to enhance fungal enzymatic activity. S. hirsutum stood out for its ability to release high concentrations of phenolic compounds (up to 6001 ± 236 mg gallic acid eq L⁻¹) and VFAs (up to 1627 ± 325 mg L⁻¹) into the aqueous extract, particularly with metal supplementation. In contrast, A. discolor was more effective in degrading phenolic compounds within the solid matrix, achieving a 41% reduction over a 30-day period. However, its ability to accumulate phenolics and VFAs in the extract was limited. Both WRF exhibited increased enzymatic activities (particularly Laccase and Manganese Peroxidase) with the addition of Cu-Mn, highlighting the potential of the aqueous extract as a natural source of biocatalysts. Phytotoxicity assays using Solanum lycopersicum seeds confirmed a partial detoxification of the treated alperujo. However, none of the fungi could entirely eliminate inhibitory effects on their own, suggesting the need for complementary stabilization steps before agricultural reuse. Overall, the results indicate that S. hirsutum, especially when combined with metal supplementation, is better suited for valorizing alperujo through the recovery of bioactive compounds. Meanwhile, A. discolor may be more suitable for detoxifying the solid phase strategies. These findings support the integration of fungal pretreatment into biorefinery schemes that valorize agroindustrial residues while mitigating environmental issues. Full article

Water quality is essential for safeguarding human health and ensuring the stability of ecosystems. Nonetheless, the rising prevalence of emerging contaminants, particularly pharmaceutical compounds, has raised serious environmental concerns due to their bioactivity, widespread use, persistence, and potential toxicity. Among these, acetaminophen (paracetamol) is one of the most frequently detected pharmaceutical pollutants in aquatic environments. Among the various degradation strategies explored, biological methods, especially those involving white-rot fungi, have shown substantial promise owing to their production of ligninolytic enzymes capable of degrading complex pollutants. This study investigates the use of laccases from Ganoderma parvulum, covalently immobilized on chitosan microspheres, for acetaminophen degradation. The immobilization involved a 10% crosslinking agent, 60-min crosslinking time, and 10,000 U/L enzyme concentration, resulting in an immobilization efficiency of 123%, 203%, and 218%, respectively. The immobilized enzymes displayed enhanced stability across pH 3–8 and temperatures between 20 and 60 °C. Biodegradation assays achieved 97% acetaminophen removal within four hours. Nuclear Magnetic Resonance (¹H NMR and COSY) confirmed structural transformation. The enzymes also retained over 95% catalytic activity after multiple reuse cycles. These findings highlight the novel application of laccases as efficient and reusable biocatalysts for pharmaceutical pollutant removal, providing valuable insights into the mechanisms of enzymatic environmental remediation. Full article