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Laccase is a green catalyst that can efficiently catalyze phenolic pollutants, and its catalytic efficiency is closely related to the interaction between enzyme and substrates. To investigate the binding effects between enzyme and phenolic pollutants, phenol, p-chlorophenol, and bisphenol A were used as substrates in this study. We focused on the removal and catalytic mechanism of these pollutants in water using yellow laccase derived from Coriolopsis gallica. The enzymatic catalytic products were characterized using Ultraviolet-Visible Absorption Spectroscopy (UV-Vis), Fourier Transform Infrared Spectroscopy (FTIR), and High-Resolution Mass Spectrometry (HRMS), and the catalytic mechanism of laccase on phenolic pollutants was further explored by molecular docking. Based on the structural characterization and molecular docking results, the possible polymerization pathways of these phenolic compounds were speculated. Laccase catalyzed phenol to produce phenolic hydroxyl radicals, their para-radicals, and ortho-radicals, which polymerized to form oligomers linked by benzene‑oxygen-benzene and benzene-benzene. P-chlorophenol produced phenolic hydroxyl radicals and their ortho-radicals, polymerizing to form oligomers connected by benzene‑oxygen-benzene or benzene-benzene. The CC bond of the isopropyl group of bisphenol A broke to formed an intermediate product, which was further polymerized to formed a benzene‑oxygen-benzene linked oligomer., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Many protein-ionic liquid investigations have examined laccase interactions. Laccases are a class of poly-copper oxidoreductases that retain significant biotechnological relevance owing to their notable oxidative capabilities and their application in the elimination of synthetic dyes, phenolic compounds, insecticides, and various other substances. This study investigates the impact of surface active ionic liquids (SAILs), namely, decyltrimethylammonium bromide [N 10111 ][Br] and 1-decyl-3-methylimidazolium chloride [C 10mim ][Cl] as cationic surfactant ionic liquids and cholinium decanoate [Chl][Dec], an anionic surfactant ionic liquid, on the structure and function of laccase from the fungus Trametes versicolor (TvL) by the molecular dynamics (MD) simulation method. In summary, this study showed that laccase solvent-accessible surface area increased in the ionic liquid [Chl][Dec] while it decreased in the other two ionic liquids. Interestingly, [Chl][Dec] ionic liquid components formed hydrogen bonds with laccase, while [N 10111 ][Br] and [C 10mim ][Cl] components were unable to form hydrogen bonds with laccase. The quantity of hydrogen bonds formed between water molecules and the enzyme was also diminished in the presence of [Chl][Dec] in comparison to the other two ionic liquids. especially at a concentration of 250 mM. In 250 mM concentrations of [N 10111 ][Br] and [C 10mim ][Cl], clusters of long-chain cations are likely to form near the copper T1 site. However, even at low [Chl][Dec] concentrations, long [Dec] - chains were observed to penetrate the enzyme near the copper T1 site, and at 250 mM [Chl][Dec], a large cluster of anions occupied the opening of the active site. The results of the analysis also show that the interaction between the [Dec] - anion and the enzyme is stronger than the interaction between [N 10111 ] + and [C 10mim ] + with laccase; in addition, the [Dec] - anion, compared to [Br] - and [Cl] - has a much greater tendency to bind with the enzyme residues., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Laccase is capable of catalyzing a vast array of reactions, but its low redox potential limits its potential applications. The use of photocatalytic materials offers a solution to this problem by converting absorbed visible light into electrons to facilitate enzyme catalysis. Herein, MIL-53(Fe) and NH 2 -MIL-53(Fe) serve as both light absorbers and enzyme immobilization carriers, and laccase is employed for solar-driven chemical conversion. Electron spin resonance spectroscopy results confirm that visible light irradiation causes rapid transfer of photogenerated electrons from MOF excitation to T1 Cu(II) of laccase, significantly increasing the degradation rate constant of tetracycline (TC) from 0.0062 to 0.0127 min -1 . Conversely, there is only minimal or no electron transfer between MOF and laccase in the physical mixture state. Theoretical calculations demonstrate that the immobilization of laccase's active site and its covalent binding to the metal-organic framework surface augment the coupled system's activity, reducing the active site accessible from 27.8 to 18.1 Å. The constructed photo-enzyme coupled system successfully combines enzyme catalysis' selectivity with photocatalysis's high reactivity, providing a promising solution for solar energy use., (© 2024 Wiley‐VCH GmbH.)

Laccase is well-known for its eco-friendly applications in environmental remediation and biotechnology, but its high cost and low stability have limited its practical use. Therefore, there is an urgent need to develop efficient laccase mimetics. In this study, a novel laccase-mimicking nanozyme (MBI-Cu) was successfully synthesized using 2-methylbenzimidazole (MBI) coordinated with Cu 2+ by mimicking the copper active site and electron transfer pathway of natural laccase. MBI-Cu nanozyme exhibited excellent catalytic activity and higher stability than laccase, and was utilized to oxidize a series of phenolic compounds. Environmental pollutant aminophenol isomers were found to display different color in solution when catalytically oxidized by MBI-Cu, which provided a simple and feasible method to identify them by the naked eye. Based on the distinct absorption spectra of the oxidized aminophenol isomers, a colorimetric method for quantitatively detecting o-AP, m-AP, and p-AP was established, with detection limits of 0.06 μM, 0.27 μM, and 0.18 μM, respectively. Furthermore, by integrating MBI-Cu-based cotton pad colorimetric strips with smartphone and utilizing color recognition software to identify and analyze the RGB values of the images, a portable colorimetric sensing platform was designed for rapid detection of aminophenol isomers without the need for any analytical instrument. This work provides an effective reference for the design of laccase nanozymes and holds significant potential for applications in the field of environmental pollutant monitoring., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Phenols and phenolic compounds are major plant metabolites used in industries to produce pesticides, dyes, medicines, and plastics. These compounds enter water bodies, soil, and living organisms via such industrial routes. Some polyphenolic compounds like phenolic acids, flavonoids have antioxidant and organoleptic qualities, as well as preventive effects against neurodegenerative illnesses, cardiovascular disease, diabetes, and cancer. However, many of the polyphenolic compounds, such as Bisphenol A, phthalates, and dioxins also cause major environmental pollution and endocrine disruption, once the dose level becomes objectionable. The development of reliable and rapid methods for studying their dose dependency, high-impact detrimental effects, and continuous monitoring of phenol levels in humans and environmental samples is a crucial necessity of the day. Enzymatic biosensors employing phenol oxidases like tyrosinase, peroxidase and laccase, utilizing electrochemical amperometric methods are innovative methods for phenol quantification. Enzymatic biosensing, being highly sensitive and efficacious technique, is illuminated in this review article as a progressive approach for phenol quantification with special emphasis on laccase amperometric biosensors. Even more, the review article discussion is extended up to nanozymes, composites of metal organic frameworks (MOFs), and molecularly imprinted polymers (MIPs) as some emerging species for electro-chemical sensing of phenols. Applications of phenol quantification and green biosensing are also specified. A concrete summary of the innovative polyphenol detection approaches with futuristic scope indicates a triumph over some existing constraints of the phenomenological approaches providing an informative aisle to the modern researchers towards the bulk readability., Competing Interests: Declaration of competing interest The authors declare no competing interests., (Copyright © 2024 Elsevier B.V. All rights reserved.)

To achieve efficient dye degradation, we reported a visible light-driven biomass photo-enzyme coupled system, which was constructed by assembling g-C 3 N 4 during in situ culture and immobilizing laccase via metal-organic framework (MOF). Benefited from the network and porous structure of bacterial cellulose (BC), the g-C 3 N 4 could be stably interspersed, and MOF grew g-C 3 N 4 /BC to encapsulate laccase. BC improves the reusability of the system, while combined with MOF encapsulation, avoiding direct contact between photo- and enzyme- catalysts. Importantly, thanks to the existence of electron transfer from photocatalysis to enzyme, the photogenerated electron hole recombination within the photocatalyst reduced, improving catalyzed reaction efficiency. The degradation efficiency of the catalysis system within 10 min for methylene blue and rhodamine B could reach 100 % and 96.1 %, respectively, which could rapidly degrade dye and recycle for more than 10 times. This research can shine new light on the development of advanced wastewater treatment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Although traditional Fe-based nanozymes have shown great potential, generally only a small proportion of the Fe atoms on the catalyst's surface are used. Herein, we synthesized single-atom Fe on N-doped graphene nanosheets (Fe-CNG) with high atom utilization efficiency and a unique coordination structure. Active oxygen species including superoxide radicals (O 2 •- ) and singlet oxygen ( 1 O 2 ) were efficiently generated from the interaction of the Fe-CNG with dissolved oxygen in acidic conditions. The Fe-CNG nanozymes were found to display enhanced oxidase-like and laccase-like activity, with V max of 2.07 × 10 -7  M∙S -1 and 4.54 × 10 -8  M∙S -1 and K m of 0.324 mM and 0.082 mM, respectively, which is mainly due to Fe active centers coordinating with O and N atoms simultaneously. The oxidase-like performance of the Fe-CNG can be effectively inhibited by ascorbic acid (AA) or hydroquinone (HQ), which can directly obstruct the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB). Therefore, a direct and sensitive colorimetric method for the detection of AA and HQ activity was established, which exhibited good linear detection and limit of detection (LOD) of 0.048 μM and 0.025 μM, respectively. Moreover, a colorimetric method based on the Fe-CNG catalyst was fabricated for detecting the concentration of AA in vitamin C. Therefore, this work offers a new method for preparing a single-atom catalyst (SAC) nanozyme and a promising strategy for detecting AA and HQ., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH, DE part of Springer Nature.)

Laccases with highly catalytic properties have been widely used in developing green applications for water remediation. However, the poor stability and low reutilization rate of free laccase make it difficult to be applied practically. Hence, in this study, an immobilized laccase was prepared using dopamine (DA) functionalized sodium alginate (SA)/polyethylene glycol (PEG) composite hydrogels to realize the recyclability of the laccase. The SA/PEG composite hydrogels, as the protective carrier for laccase, exhibited excellent catalytic stability in various interfering environments. After 30 days, Lac@SA-PDA/PEG beads could remain 70.23 % of the initial activity, as the residual activity of free laccase was only 12.35 %. When free laccase and Lac@SA-PDA/PEG beads were used for decolorization of Reactive Blue 19 (RB-19,100 mg/L), the degradation rate of Lac@SA-PDA/PEG is 6.88 times higher than free laccase. More importantly, the SA-PDA/PEG composite hydrogel exhibited a high reutilization rate, which after six cycles, Lac@SA-PDA/PEG beads retained 90.23 % of its initial activity. Besides, the degradation effect of Lac@SA-PDA/PEG on different dyes was analyzed. In addition, the conjectured degradation pathways of RB-19 by laccase were analyzed. The work showed that immobilized laccase has tremendous potential for the treatment of dyestuff wastewater., Competing Interests: Declaration of competing interest Authors declare no conflicting interests., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Laccase is an enzyme known for its eco-friendly uses in environmental cleanup and biotechnology. However, it has limitations such as low stability, high cost, and complex recycling. So, there is a need for laccase mimics that can effectively imitate its properties. Herein, we created copper formate-lysine nanoparticles (Cuf-Lys) that mimic laccase's activity. The developed Cuf-Lys demonstrated remarkable polyphenol oxidase-like activity, stability, and recyclability, making them suitable for the fabrication of efficient colorimetric sensors for the detection of epinephrine. These sensors had a specific response and could accurately measure epinephrine concentrations ranging from 2.5 to 50 μM, with a detection limit as low as 1 μM. Furthermore, the biosensor demonstrated high sensitivity and selectivity when applied to the detection of rutin. The limit of detection for rutin was determined to be 0.16 μM while in the linear concentration range of 0.25 to 150.0 μM. We believe that Cuf-Lys provide a new route for the design of laccase mimics, showing potential applications for biomedical diagnosis and environmental monitoring., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH, DE part of Springer Nature.)

In contrast to natural enzymes, nanozymes show promising advantages of low cost and high stability for analytical applications. The simple mix of L-phenylalanine (F) and Cu 2+ produces two-dimensional nanosheets of a coordination polymer with a high surface area ratio and rich exposed active sites as a novel catalyst. As the mimetic of natural laccase, this nanozyme (F-Cu) can catalyze the oxidative coupling reaction of 2,4-dichlorophenol (2,4-DP) and 4-aminoantipyrine (4-AP) to produce a distinct red product, thus establishing an intuitive and simple method for the detection of thiram. In the range of 0-7.5 μM, the absorbance intensity was linearly related to the concentration of thiram, and the detection limit was 0.0845 μM. The F-Cu nanozyme was successfully applied to the colorimetric detection of thiram in real samples.

Laccase, the selectively lignin degrader, vital to the initiation of lignocellulosic deconstruction was immobilized onto activated agarose beads to increase its reuse potential. Laccase cross-linked beads (~ 3.42 mm) recorded a specific activity of 23 Umg - 1 , retaining about 80.43% enzyme activity after 45 days of storage. The immobilization yield and efficiency were 89% and 97% respectively. The equilibrium data fitted the Freundlich equation (R 2  = 0.9987) demonstrating multilayer adsorption and the presence of Cu, Fe, and S in the elemental analysis of immobilized beads established effective binding between activated agarose beads and the laccase protein. Characterization studies of the immobilized laccase-treated crop residues revealed significant differences in the lignin polymer after each treatment cycle. An increase in digestibility of 26.21% and 7.62% was observed in paddy and finger millet-treated straws respectively, over the controls corroborating efficient lignin depolymerization. The propitious performance of laccase beads authenticated in the batch enzymatic reactor to treat crop residues paves headway as a sustainable green technology in the deconstruction of crop residues for use as ruminant feed, augmenting productivity., (© 2024. The Author(s).)

Laccase mediators possess advantage of oxidizing substrates with high redox potentials, such as aflatoxin B 1 (AFB 1 ). High costs of chemically synthesized mediators limit laccase industrial application. In this study, thin stillage extract (TSE), a byproduct of corn-based ethanol fermentation was investigated as the potential natural mediator of laccases. Ferulic acid, p-coumaric acid, and vanillic acid were identified as the predominant phenolic compounds of TSE. With the assistance of 0.05 mM TSE, AFB 1 degradation activity of novel laccase Glac1 increased by 17 times. The promoting efficiency of TSE was similar to ferulic acid, but superior to vanillic acid and p-coumaric acid, with 1.2- and 1.3-fold increases, respectively. After Glac1-TSE treatment, two oxidation products were identified. Ames test showed AFB 1 degradation products lost mutagenicity. Meanwhile, TSE also showed 1.3-3.0 times promoting effect on laccase degradation activity in cereal flours. Collectively, a safe and highly efficient natural mediator was obtained for aflatoxin detoxification., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Protein immobilization using water-soluble ionic metal-organic polyhedra (MOPs) acting as porous spacers has recently been demonstrated as a potent strategy for the preparation of biocatalysts. In this article, we describe a mixed-protein approach to achieve biocomposites with adjustable enzyme contents and excellent immobilization efficiencies, in a systematic and well-controlled manner. Self-assembly of either cationic or anionic MOPs with bovine serum albumin or egg white lysozyme combined with enzymes (alkaline phosphatase, laccase or cytochrome c) led to solid-state catalysts with a high retention of enzyme activity. Furthermore, for all these systems, the dilution of enzymes within the solid-state composite led to noticeably improved catalytic performances, with both higher specific activity and affinity for substrate.

The detection of endogenous phenolic compounds (EPs) in food is of great significance in elucidating their bioactivity and health effects. Here, a novel bifunctional vanillic acid-Cu (VA-Cu) nanozyme with peroxidase-like and laccase-like activities was successfully prepared. The peroxidase mimic behavior of VA-Cu nanozyme can catalyze 3,3',5,5'-tetramethylbenzidine (TMB) to generate oxidized TMB (oxTMB). Owing to the high reducing power of EPs, this process can be inhibited, and the degree of inhibition increases with the increase of reaction time. Additionally, owing to the outstanding laccase mimic behavior of the VA-Cu, it can facilitate the oxidation of various EPs, resulting in the formation of colored quinone imines, and the degree of catalysis increases with the increase of reaction time. Based on the interesting experimental phenomena mentioned above, a six-channel nanozyme sensor array (2 enzyme-mimic activities × 3 time points = 6 sensing channels) was constructed, successfully achieving discriminant analysis of nine EPs. In addition, the combination of artificial neural network (ANN) algorithms and sensor arrays has successfully achieved accurate identification and prediction of nine EPs in black tea, honey, and grape juice. Finally, a portable method for identifying EPs in food has been proposed by combining it with a smartphone.

Background: Hazardous synthetic dye wastes have become a growing threat to the environment and public health. Fungal enzymes are eco-friendly, compatible and cost-effective approach for diversity of applications. Therefore, this study aimed to screen, optimize fermentation conditions, and characterize laccase from fungal endophyte with elucidating its ability to decolorize several wastewater dyes., Results: A new fungal endophyte capable of laccase-producing was firstly isolated from cladodes of Opuntia ficus-indica and identified as T. harzianum AUMC14897 using ITS-rRNA sequencing analysis. Furthermore, the response surface methodology (RSM) was utilized to optimize several fermentation parameters that increase laccase production. The isolated laccase was purified to 13.79-fold. GFC, SDS-PAGE revealed laccase molecular weight at 72 kDa and zymogram analysis elucidated a single band without any isozymes. The peak activity of the pure laccase was detected at 50 °C, pH 4.5, with thermal stability up to 50 °C and half life span for 4 h even after 24 h retained 30% of its activity. The K m and V max values were 0.1 mM, 22.22 µmol/min and activation energy (E a ) equal to 5.71 kcal/mol. Furthermore, the purified laccase effectively decolorized various synthetic and real wastewater dyes., Conclusion: Subsequently, the new endophytic strain produces high laccase activity that possesses a unique characteristic, it could be an appealing candidate for both environmental and industrial applications., (© 2024. The Author(s).)

A promising water treatment technology involves inducing the polymerization of organic pollutants to form corresponding polymers, enabling rapid, efficient, and low CO 2 emission removal of these pollutants. However, there is currently limited research on utilizing polymerization treatment technology for removing tetracyclines from water. In this study, we synthesized a laccase-mimic nanozyme (Cu-ATZ) with a high Cu + ratio using 2-amino-1,3,4-thiadiazole as a ligand inspired by natural laccase. The Cu-ATZ exhibited enhanced resistance to more severe application conditions and improved stability compared to natural laccase, thereby demonstrating a broader range of potential applications. The excellent catalytic properties of Cu-ATZ enabled the nanozyme to be used in the polymerization process to remove tetracyclines from water. In order to simulate actual antibiotic pollution of water bodies, tetracyclines were added to the water from sewage treatment plants. Following Cu-ATZ treatment of the water sample, the chemical oxygen demand (COD) content was found to have decreased by over 80 %. In conclusion, this study presented a novel approach for tetracycline elimination from water., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Aging workers of the termite Neocapritermes taracua can defend their colony by sacrificing themselves by body rupture, mixing the externally stored blue laccase BP76 with hydroquinones to produce a sticky liquid rich in toxic benzoquinones. Here, we describe the crystal structure of BP76 isolated from N. taracua in its native form. The structure reveals several stabilization strategies, including compact folding, glycosylation, and flexible loops with disulfide bridges and tight dimer interface. The remarkable stability of BP76 maintains its catalytic activity in solid state during the lifespan of N. taracua workers, providing old workers with an efficient defensive weapon to protect their colony., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 Elsevier Inc. All rights reserved.)

The discovery of natural product-derived novel nanopesticide systems can effectively address the adverse effects caused by the improper use of traditional fungicides. In this research, 33 novel 3-carene-derived amide-thiourea derivatives 5a - 5zg were designed using laccase as the biological target, synthesized from natural renewable forest biomass resource 3-carene as the starting material, and structurally confirmed by Fourier-transform infrared spectroscopy, nuclear magnetic resonance, high-resolution mass spectrometry, and single crystal X-ray diffraction. The antifungal activity of the target compounds against eight plant pathogenic fungi was evaluated, and the results presented that target compound 5g exhibited excellent and broad-spectrum antifungal activity against the eight tested phytopathogenic fungi. Furthermore, the important contribution of the gem -dimethylcyclopropane structure in the antifungal activity of compound 5g was revealed through two negative controls without the gem -dimethylcyclopropane structure. Besides, compound 5g also demonstrated a prominent laccase inhibitory activity. The fluorescence quenching of the laccase with compound 5g , the chelating characteristics of compound 5g , and the interaction mode between the laccase and compound 5g presented that the target compound 5g probably exhibited excellent antifungal activity by acting on the laccase target. Cytotoxicity assay revealed that compound 5g had a low cytotoxicity for LO2 and HEK293T cell lines. On the other hand, to further improve the application potential of compound 5g , the 3-carene molecular skeleton containing gem -dimethylcyclopropane ring was grafted onto chitosan, and two nanopesticide carriers CACS and CATCS with sustained releasing performance were synthesized for loading compound 5g . 3-Carene-derived nanochitosan carrier CATCS showed a relatively regular, loose, and porous reticular structure, which displayed high dispersibility and good thermostability. In addition, this carrier had a higher drug-loading capacity and sustained releasing performance than that of the unmodified chitosan. This research identified that the target compound 5g could be used as a promising lead compound for fungicide against the laccase target, meanwhile, the complex 5g /CATCS deserved further study as a nanopesticide candidate.

The current study tries to find the impact of the integration of laccase enzyme (Lac) onto magnetized chitosan (Cs) nanoparticles composed of molybdenum disulfide (MoS 2 NPs) (Fe 3 O 4 /Cs/MoS 2 /Lac NPs) on the removal of AFM 1 in milk samples. The Fe 3 O 4 /Cs/MoS 2 /Lac NPs were characterized by FT-IR, XRD, BET, TEM, FESEM, EDS, PSA, and VSM analysis. The cytotoxic activity of the synthesized nanoparticles in different concentrations was evaluated using the MTT method. The results show that the synthesized nanoparticles don't have cytotoxic activity at concentrations less than 20 mg/l. The ability of the prepared nanoparticles to remove AFM 1 was compared by bare laccase enzyme, MoS 2 , and Fe 3 O 4 /Cs/MoS 2 composite, indicating that the Fe 3 O 4 /Cs/MoS 2 /Lac NPs the highest adsorption efficiency toward AFM 1 . Besides, the immobilization efficiency of laccase with a concentration range of 0.5-2.0 was investigated, indicating that the highest activity recovery of 96.8% was obtained using 2 mg/ml laccase loading capacity. The highest removal percentage of AFM 1 (68.5%) in the milk samples was obtained by the Fe 3 O 4 /Cs/MoS 2 /Lac NPs at a contact time of 1 h. As a result, Fe 3 O 4 /MoS 2 /Cs/Lac NPs can potentially be utilized as an effective sorbent with high capacity and selectivity to remove AFM 1 from milk samples., Competing Interests: Declaration of competing interest The authors have declared no conflict of interest., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Facing the increasingly prominent tetracycline pollution and the resulting environmental problems, how to find environmental and efficient treatment means is one of the current research hotspots. In this study, the laccase surface-display technology for tetracycline treatment was investigated. Via study, the type of anchoring protein had a minor influence on the laccase ability, while the type of laccase showed a major impact. Bacillus subtilis spore coat protein (CotA) exhibited higher laccase activity, stability, and efficiency in degrading tetracycline than Pleurotus ostreatus laccase 6 (Lacc6). The superiority of bacterial laccase over fungal laccase was elucidated from the perspective of crystal structure. Besides, a variety of technical means were used to verify the success of surface-display. pGSA-CotA surface-displayed bacteria exhibited good tolerance to high temperature, pH, and various heavy metals. Importantly, surface-displayed bacteria showed faster degradation efficiency and better treatment effects than the intracellular expression bacteria in tetracycline degradation. This implies that surface display technology has greater potential for laccase-mediated environmental remediation. Due to the adverse impacts of tetracycline on soil enzyme activity and microorganisms, our study found that pGSA-CotA surface-displayed bacteria can alleviate tetracycline stress in soil and partially activate the soil, thereby increasing soil enzyme activity and certain nitrogen cycling genes., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

Laccases hold great potential for biotechnological applications, particularly in environmental pollutant remediation. Laccase activity is governed by the solvent environment, and ionic liquids (ILs) emerge as a versatile solvent for activation or stabilization of enzymes. Herein, effects of cholinium-based ILs formulated with carboxylic acids, inorganic acid, and amino acids as anionic species, on the catalytic activity of laccase from Trametes versicolor were investigated by experimental and computational approaches. Experimental results showed that laccase activity was enhanced by 21.39 % in 0.5 M cholinium dihydrogen citrate ([Cho][DHC]), in relation to the laccase activity in phosphate buffer medium. However, cholinium aminoate ILs negatively affected laccase activity, as evidenced by the partial deactivation of laccase in both cholinium glycinate and cholinium phenylalaninate, at concentrations of 0.1 M and 0.5 M, respectively. Molecular dynamics studies revealed that the enhancement of laccase activity in [Cho][DHC] might be attributed to the highly stabilized and compact structure of laccase, facilitating a better internal electron transfer during the laccase-substrate interactions. Enhanced catalytic performance of laccase in [Cho][DHC] was postulated to be driven by the high accumulation level of dihydrogen citrate anions around laccase's surface. [Cho][DHC] holds great promise as a cosolvent in laccase-catalyzed biochemical reactions., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

The escalating threat of malachite green (MG) pollution poses significant risks to ecosystems. Saturation mutation targeting Tyr230 of small laccase (SLAC) from Streptomyces coelicolor yielded Y230R, exhibiting a remarkable 104 % increase in specific activity. Notably, this mutation achieved dual enhancements in both activity and pH stability. Molecular dynamics simulation revealed higher structural stability of Y230R compared to wild-type (WT) across varying pH levels. The increased count of hydrogen bonds in Y230R compared to WT may be contribute to its stability. Y230R demonstrated superior catalytic efficiency (67.0 %) in MG decolorization, maintaining over 90 % activity after 30 min incubation in MG solution (500 mg/L), highlighting enhanced tolerance compared to WT. Molecular docking analysis attributed the differential catalytic effects on MG and ABTS to structural disparities and hydrogen bonding. Y230R stands as a promising composite mutant for future laccase engineering and industrial applications., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Laccase (EC 1.10.3.2), as eco-friendly biocatalysts, holds immense potential for sustainable applications across various environmental and industrial sectors. Despite the growing interest, the exploration of cold-adapted laccases, especially their unique properties and applicability, remains limited. In this study, we have isolated, cloned, expressed, and purified a novel laccase from Peribacillus simplex (GenBank: PP430751), which was derived from permafrost layer. The recombinant laccase (PsLac) exhibited optimal activity at 30 °C and a pH optimum of 3.5. Remarkably, PsLac exhibited remarkable stability in the presence of organic solvents, with its enzyme activity increasing by 20 % after being incubated in a 30 % trichloromethane solution for 12 h, compared to its initial activity. Furthermore, the enzyme preserved 100 % of its activity after undergoing eight freeze-thaw cycles. Notably, the catalytic center of PsLac contains Zn 2+ instead of the typically observed Cu 2+ found in other laccases, and metal-ion substitution experiments raised the catalytic efficiency to 3-fold when Zn 2+ was replaced with Fe 2+ . Additionally, PsLac has demonstrated a proficient ability to degrade phenolic pollutants, such as hydroquinone, even at a low temperature of 16 °C, positioning it as a promising candidate for environmental bioremediation and contributing to cleaner production processes., Competing Interests: Declaration of competing interest The authors declare that they have no competing interests., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Banana fibers are a sustainable material with natural mechanical strength and antibacterial properties. These fibers are extracted from the large amount of waste produced by banana pseudo stems annually. However, despite their numerous advantages, their stiffness and rough texture impede their full use in the textile. This research investigates the degumming treatment of banana fibers using enzyme combination and chemical methods to achieve spinnable soft banana fibers. An L9 orthogonal array was used in a Taguchi design of the experiment to optimize the process parameters. For enzyme combination degumming, the experimental setup comprised different quantities of hemicellulase, laccase, amylase, and pectinase; for chemical degumming, varied amounts of sodium hydroxide (NaOH) were used. The results indicate that enzyme-based degumming procedures produce better results than chemical treatments. Optimum enzyme combinations for various fiber qualities were found using the Taguchi design of experiments. These combinations included Hemicellulase 5 %, Laccase 5 %, Amylase 3 %, and Hemicellulase 5 %, Laccase 3 %, Pectinase 5 %. Without degrading the cellulose structure, these ideal enzyme combinations produced fibers with lower lignin content and higher cellulose percentages, moisture content, and tenacity values. By determining the most efficient enzyme combinations and their effects on fiber qualities, the study offers sustainable fiber processing methods for textile grade banana fiber., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

A novel laccase mimic enzyme Cu-Mn with excellent photothermal properties was firstly prepared via a combination of hydrothermal and in situ synthesis. Cu-Mn nanozymes could catalyze the typical laccase substrate 2,4-dichlorophenol (2,4-DP) to generate the red quinone imine. Further, loading the MnO 2 nanosheets with photothermal properties, Cu-Mn nanozymes possessed not only excellent laccase catalytic activity, but also high photothermal conversion efficiency. The presence of glutathione S-transferase (GST) recovered the glutathione (GSH)-induced weakness of the laccase activity and photothermal properties of Cu-Mn. Hence, a GST enzyme-regulated dual-mode sensing strategy was established based on Cu-Mn nanozymes. The detection limits of GST monitoring based on colorimetric and photothermal methods were 0.092 and 0.087 U/L with response times of 20 min and 8 min, respectively. Furthermore, the proposed method enabled the measuring of GST levels in human serum and was successfully employed in the primary evaluation of hepatitis patients. Another attraction, the impressive photothermal behavior also endowed the Cu-Mn nanozymes with promising antimicrobial properties, which exhibited significant antimicrobial effects against Escherichia coli (E.coli) and Staphylococcus aureus (S.aureus). Unsurprisingly, multifunctional Cu-Mn nanozymes certainly explore new paths in biochemical analysis and antimicrobial applications., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Laccase, a prominent enzyme biomacromolecule, exhibits promising catalytic efficiency in degrading phenolic compounds like bisphenol A (BPA). The laccase immobilized on conventional materials frequently demonstrates restricted loading and suboptimal catalytic performance. Hence, there is a pressing need to optimized external surface utilization to enhance catalytic performance. Herein, we synthesized amino-functionalized modified silica particles with a hierarchical hollow silica spherical (HHSS) structure for laccase immobilization via crosslinking, resulting in HHSS-LE biocatalysts. Through Box-Behnken design (BBD) and response surface methodology (RSM), we achieved a remarkably high enzyme loading of up to 213.102 mg/g. The synergistic effect of adsorption by HHSS and degradation by laccase facilitated efficient removal of BPA. The HHSS-LE demonstrated superior BPA removal capabilities, with efficiencies exceeding 100 % in the 50-200 mg/L BPA concentration range. Compared to MCM-41 and solid silica spheres (SSS), HHSS showed the highest enzyme loading capacity and catalytic activity, underscoring its superior external surface utilization rate per unit mass. Remarkably, the HHSS-LE biocatalyst exhibited remarkable recyclability even after 11 successive cycles of reuse. By preparing high immobilization rate with efficient external surface utilization, this study lays the foundation for the design of universally applicable and efficient enzyme immobilization catalysts., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

With rapid industrial expansion, environmental pollution from emerging contaminants has increased, posing severe ecosystem threats. Laccases offer an eco-friendly solution for degrading hazardous substances, but their use as free-form biocatalysts face challenges. This study immobilized laccase (PersiLac1) on green-synthesized Si@Fe nanoparticles (MSFM NPs) to remove pollutants like Malachite Green-containing wastewater and degrade plastic films. Characterization techniques (FTIR, VSM, XRD, SEM, EDS, BET) confirmed the properties and structure of MSFM NPs, revealing a surface area of 31.297 m 2 .g -1 and a pore diameter of 12.267 nm. The immobilized PersiLac1 showed enhanced activity across various temperatures and pH levels, retaining over 82 % activity after 15 cycles at 80°C with minimal leaching. It demonstrated higher stability, half-life, and decimal reduction time than free laccase. Under 1 M NaCl, its activity was 1.8 times higher than the non-immobilized enzyme. The immobilized laccase removed 98.11 % of Malachite Green-containing wastewater and retained 82.92 % activity over twenty cycles of dye removal. Additionally, FTIR and SEM confirmed superior plastic degradation under saline conditions. These findings suggest that immobilizing PersiLac1 on magnetic nanoparticles enhances its function and potential for contaminant removal. Future research should focus on scalable, cost-effective laccase immobilization methods for large-scale environmental applications., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

A fungal laccase-mediator system capable of high effectively oxidizing tetracyclines under a wide pH range will benefit environmental protection. This study reported a directed evolution of a laccase PIE5 to improve its performance on tetracyclines oxidization at alkaline conditions. Two mutants, namely MutA (D229N/A244V) and MutB (N123A/D229N/A244V) were obtained. Although they shared a similar optimum pH and temperature as PIE5, the two mutants displayed approximately 2- and 5-fold higher specific activity toward the mediators ABTS and guaiacol at pHs 4.0 to 6.5, respectively. Simultaneously, their catalytic efficiency increased by 8.0- and 6.4-fold compared to PIE5. At a pH range of 5-8 and 28 °C, MutA or MutB at a final concentration of 2.5 U·mL -1 degraded 77 % and 81 % of 100 mg·L -1 tetracycline within 10 min, higher than PIE5 (45 %). Furthermore, 0.1 U·mL -1 MutA or MutB completely degraded 100 mg·L -1 chlortetracycline within 6 min in the presence of 0.1 mM ABTS. At pH 8.0, MutA degraded tetracycline and chlortetracycline following the routine pathways were reported previously based on LC-MS analysis., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The cyst wall of the eye pathogen Acanthamoeba castellanii contains cellulose and has ectocyst and endocyst layers connected by conical ostioles. Cyst walls contain families of lectins that localize to the ectocyst layer (Jonah) or the endocyst layer and ostioles (Luke and Leo). How lectins and an abundant laccase bind cellulose and why proteins go to locations in the wall are not known and are the focus of the studies here. Structural predictions identified β-jelly-roll folds (BJRFs) of Luke and sets of four disulfide knots (4DKs) of Leo, each of which contains linear arrays of aromatic amino acids, also present in carbohydrate-binding modules of bacterial and plant endocellulases. Ala mutations showed that these aromatics are necessary for cellulose binding and proper localization of Luke and Leo in the Acanthamoeba cyst wall. BJRFs of Luke, 4DKs of Leo, a single β-helical fold (BHF) of Jonah, and a copper oxidase domain of the laccase each bind to glycopolymers in both layers of deproteinated cyst walls. Promoter swaps showed that ectocyst localization does not just correlate with but is caused by early encystation-specific expression, while localization in the endocyst layer and ostioles is caused by later expression. Evolutionary studies showed distinct modes of assembly of duplicated domains in Luke, Leo, and Jonah lectins and suggested Jonah BHFs originated from bacteria, Luke BJRFs share common ancestry with slime molds, while 4DKs of Leo are unique to Acanthamoeba .IMPORTANCE Acanthamoebae is the only human parasite with cellulose in its cyst wall and conical ostioles that connect its inner and outer layers. Cyst walls are important virulence factors because they make Acanthamoebae resistant to surface disinfectants, hand sanitizers, contact lens sterilizers, and antibiotics applied to the eye. The goal here was to understand better how proteins are targeted to specific locations in the cyst wall. To this end, we identified three new proteins in the outer layer of the cyst wall, which may be targets for diagnostic antibodies in corneal scrapings. We used structural predictions and mutated proteins to show linear arrays of aromatic amino acids of two unrelated wall proteins are necessary for binding cellulose and proper wall localization. We showed early expression during encystation causes proteins to localize to the outer layer, while later expression causes proteins to localize to the inner layer and the ostioles., Competing Interests: The authors declare no conflict of interest.

Chemoselective arylation of 5-aminopyrazoles was performed through oxidative formation of orthoquinones from catechols catalyzed by Myceliophthora thermophila laccase (Novozym 51003), and subsequently nucleophilic attack of 5-aminopyrazole to the catechol intermediates. The C-4 arylated products were obtained under extremely mild conditions without the need for amine protection or halogenation of the substrates. From this method, 10 derivatives with moderate to good efficiency (42-94%) were prepared., Competing Interests: NO authors have competing interests., (Copyright: © 2024 Shahedi et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

The control of excess biogenic amines (BAs) is crucial for the sustainable development of fermented foods. This study aimed to screen endogenous functional strains in Doubanjiang with the capacity to degrade BAs and to elucidate their application potential. Pediococcus acidilactici L-9 (PA), which was confirmed as a safe strain by phenotypic and genotypic analyses, exhibited an efficient degradation ability on BAs, particularly regarding tyramine. Notably, the degradation of tyramine was maintained at 24.03-50.60% at different temperatures (20-40 °C), pH values (4.0-9.0), and NaCl concentrations (3-18%, w/v). Additionally, genomic data revealed the presence of the laccase-coding gene, which was demonstrated to play a pivotal role in BA degradation by heterologous expression. Further, molecular docking results indicated that the degradation of BA by laccase is closely linked to the electron transfer pathway formed by the substrate and key amino acid residues. Finally, the degradation of tyramine by PA remained within the range of 8.19-64.19% under the simulated system with 6-12% salinity. This study provided valuable insights into the safety of PA and its potential degradation capacity on BAs, particularly in mitigating tyramine accumulation, which could improve the quality of Doubanjiang and other fermented foods.

Laccases act as green catalysts for oxidative cross-coupling of phenolic antioxidnt compounds, but low stability and non-recyclability limit its application. To address that, metal-organic frameworks Cu-BTC and Cr-MOF were synthesized as supports to immobilize the efficient laccase from Cerrena sp. HYB07. The Brunauer-Emmett-Teller surface area of Cu-BTC and Cr-MOF were 1213.2 and 907.1 m 2 /g, respectively. The two carriers respectively presented pore diameters of 1.2-10 nm and 1.4-12 nm as octahedron, indicating nano-scale mesoporosity. These Cu-BTC and Cr-MOF carriers could adsorb laccase with enzyme loading of 1933.2 and 1564.4 U/g carrier, respectively. The stability and organic solvent tolerance of Cu-BTC-laccase and Cr-MOF-laccase were both obviously improved compared to free laccase. Thermal inactivation kinetics showed that both the two immobilized laccases displayed lower thermal inactivation rate constants. Importantly, the Cu-BTC-laccase and Cr-MOF-laccase both showed much higher activity for cross-coupling of ethyl ferulate than free laccase, which had 2.5-fold higher cross-coupling efficiency than that by free laccase. The ethyl ferulate coupling product was also analyzed by mass spectroscopy and the synthesis pathway of ethyl ferulate dimer was proposed. The cross coupling of ethyl ferulate required the formation of radical intermediates of ethyl ferulate generated by laccase mediated oxidation. This work paved the way for MOFs immobilized laccase for cross coupling of antioxidant phenols., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

Single-atom nanozymes have garnered significant attention due to their exceptional atom utilization and ability to establish well-defined structure-activity relationships. However, conventional pyrolytic synthesis methods pose challenges such as high energy consumption and random local environments at the active sites, while achieving non-pyrolytic synthesis of single-atom nanozymes remains a formidable technical hurdle. The present study focuses on the synthesis of laccase-like iron-based single-atom nanozymes (Fe-SAzymes) using a non-pyrolysis method facilitated by microwave irradiation. Under low iron loading conditions, Fe-SAzymes exhibited significantly enhanced laccase activity (12.1 U/mg), surpassing that of laccase by 24-fold. Moreover, Fe-SAzymes demonstrated efficient catalytic oxidation of epinephrine (EP), enabling its colorimetric detection. Owing to the remarkable laccase activity of Fe-SAzymes, the conventional nanozymes EP detection time was reduced from 60 min to 20 min, with an impressive low detection limit as low as 2.95 μM. In addition, an ultra-sensitive fluorescence method for EP detection was developed using the internal filter effect of EP oxidation products and CDs combined with carbon dots probe. The detection limit of fluorescence method was only 0.39 μM. Therefore, an visual, fast, and highly sensitive dual-mode EP detection strategy has great potential in the clinical diagnostic industry., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Laccases are the most commonly used agents for the treatment of phenolic pollutants. To address the instability and high cost of natural laccases, we investigated nucleobase-modulated copper nanomaterial with laccase-like activity. Various nucleobases, including adenine, guanine, cytosine, and thymine, were investigated as templates for Cu 2+ reduction and copper nanomaterials formation due to their coordination capacity. By comparing structure and catalytic activity, the cytosine-mediated copper nanomaterial (C-Cu) had the best laccase-like activity and other nucleobase-templated copper nanomaterials exhibited low catalytic activity under the same conditions. The mechanism of nucleobase regulation of the catalytic activity of copper nanomaterials was further analyzed using X-ray photoelectron spectroscopy and density functional theory. The possible catalytic mechanisms of C-Cu, including substrate adsorption, substrate oxidation, oxygen binding, and oxygen reduction, were proposed. Remarkably, nucleobase-modulated copper nanozymes showed high stability and catalytic oxidation performance at various pH values, temperatures, long-term storage, and high salinity. In combination with electrochemical techniques, a portable electrochemical sensor for measuring phenolic pollutants was developed. This novel sensor exhibited a good linear response to catechol (10-1000 μM) with a limit of detection of 1.8 μM and excellent selectivity and anti-interference ability. This study provides not only a new strategy for the regulation of the laccase-like activity of copper nanomaterials but also a novel tool for the effective removal and low-cost detection of phenolic pollutants., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Organochlorides and particularly chlorophenols are environmental pollutants that deserve special attention. Enzymatic membrane bioreactors may be alternatives for efficiently removing such hazardous organochlorides from aqueous solutions. We propose here a novel enzymatic membrane bioreactor comprising an ultrafiltration membrane GR81PP, electrospun fibers made of cellulose acetate, and laccase immobilized using an incubation and a fouling approach. Configurations of this biosystem exhibiting the highest catalytic activity were selected for removal of 2-chlorophenol and 4-chlorophenol from aqueous solution in an enzymatic membrane bioreactor under various process conditions. The highest removal of chlorophenols, at 88% and 74% for 2-chlorophenol and 4-chlorophenol, respectively, occurred at pH 5 and 30 °C in the GR81PP/cellulose acetate/laccase biosystem with enzyme immobilized by the fouling method. Furthermore, the GR81PP/cellulose acetate/laccase biosystem with enzyme immobilized by the fouling method exhibited significant reusability and storage stability compared with the biosystem with laccase immobilized by the incubation method. The mechanism of enzyme immobilization is based on pore blocking and cake-layer formation, while the mechanism of chlorophenols removal was identified as a synergistic combination of membrane separation and enzymatic conversion. The importance of the conducted research is due to efficient removal of hazardous organochlorides using a novel enzymatic membrane bioreactor. The study demonstrates the biosystem's high catalytic activity, reusability, and stability, offering a promising solution for environmental pollution control., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

BsCotA laccase is a promising candidate for industrial application due to its excellent thermal stability. In this research, our objective was to enhance the catalytic efficiency of BsCotA by modifying the active site pocket. We utilized a strategy combining the diversity design of the active site pocket with molecular docking screening, which resulted in selecting five variants for characterization. All five variants proved functional, with four demonstrating improved turnover rates. The most effective variants exhibited a remarkable 7.7-fold increase in catalytic efficiency, evolved from 1.54 × 10 5  M -1  s -1 to 1.18 × 10 6  M -1  s -1 , without any stability loss. To investigate the underlying molecular mechanisms, we conducted a comprehensive structural analysis of our variants. The analysis suggested that substituting Leu386 with aromatic residues could enhance BsCotA's ability to accommodate the 2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonate (ABTS) substrate. However, the inclusion of charged residues, G323D and G417H, into the active site pocket reduced k cat . Ultimately, our research contributes to a deeper understanding of the role played by residues in the laccases' active site pocket, while successfully demonstrating a method to lift the catalytic efficiency of BsCotA. KEY POINTS: • Active site pocket design that enhanced BsCotA laccase efficiency • 7.7-fold improved in catalytic rate • All tested variants retain thermal stability., (© 2024. The Author(s).)

Biodegradation of polyethylene (PE) plastics is environmentally friendly. To obtain the laccases that can efficiently degrade PE plastics, we generated 9 ancestral laccases from 23 bacterial three-domain laccases through ancestral sequence reconstruction. The optimal temperatures of the ancestral laccases were between 60 °C-80 °C, while their optimal pHs were at 3.0 or 4.0. Without substrate pretreatment and mediator addition, all the ancestral laccases can degrade low-density polyethylene (LDPE) films at pH 7.0 and 60 °C. Among them, Anc52, which shared low sequence identity (18 %-41.7 %) with the reported PE-degrading laccases, was the most effective for LDPE degradation. After the catalytic reactions at 90 °C for 14 h, Anc52 (0.2 mg/mL) induced clear wrinkles and deep pits on the PE film surface detected by scanning electron microscope, and its carbonyl and hydroxyl indices reached 2.08 and 2.42, respectively. Then, we identified the residues 203 and 288 critical for PE degradation through site-directed mutation on Anc52. Moreover, Anc52 be activated by heat treatment (60 °C and 90 °C) at pH 7.0, which gave it a high catalytic efficiency (k cat /K m = 191.73 mM -1 ·s -1 ) and thermal stability (half-life at 70 °C = 13.70 h). The ancestral laccases obtained here could be good candidates for PE biodegradation., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Faced with the escalating challenge of global plastic pollution, this study specifically addresses the research gap in the biodegradation of polystyrene (PS). A PS-degrading bacterial strain was isolated from the gut of Tenebrio molitor, and genomics, molecular docking, and proteomics were employed to thoroughly investigate the biodegradation mechanisms of Pseudomonas putida H-01 against PS. Using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (ATR-FTIR), and contact angle analysis, significant morphological and structural changes in the PS films under the influence of the H-01 strain were observed. The study revealed several potential degradation genes and ten enzymes that were specifically upregulated in the PS degradation environment. Additionally, a novel protein with laccase-like activity, LacQ1, was purified from this strain for the first time, and its crucial role in the PS degradation process was confirmed. Through molecular docking and molecular dynamics (MD) simulations, the interactions between the enzymes and PS were detailed, elucidating the binding and catalytic mechanisms of the degradative enzymes with the substrate. These findings have deepened our understanding of PS degradation., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Laccase is a copper-containing polyphenol oxidase that can oxidize phenolic and non-phenolic organic substrates. In the past decades, laccases had received considerable attention because of the ability to degrade various organic substances. Based on the codon preference of the Pichia pastoris expression system, this study optimized the gene structure of the laccase gene Lcc1 from Coprius cinerea through synthetic biology methods. A new gene Lcc1I was synthesized and heterologously expressed in P. pastoris. After 3 days of cultivation in a shake flask at 30°C, the transformants produced at a yield of 890 mg L -1 protein. The highest production level of the recombinant laccase was 2760 U L -1 . The molecular mass of the recombinant laccase was estimated at 60 kDa. The enzyme showed highest activity at pH 3.4 and 45°C. It possessed better stability at higher pH and lower temperature condition. Using 2,2'-azino-bis-(3-ethylbenzothiazoline)-6-sulphonate (ABTS) as the substrate, the K m and V max values were 0.136 mM and 9778 μM min -1  mg -1 , respectively. The recombinant laccase could directly oxidize some triphenylmethane dyes like leuco-crystal violet (LCV) and leuco-malachite green (LMG). With the help of ABTS mediator, it could oxidize and degrade 77.7% crystal violet (CV) and 79.2% malachite green (MG) within 1 h. Our results indicate that optimization of the laccase gene achieves good expression results in the host system. The dye degradation model constructed in this study may also be applied to the degradation of other organic pollutants and toxic substances, providing new solutions for environmental remediation against the increasingly severe environmental pollution., (© 2024 John Wiley & Sons Ltd.)

Laccases are extensively used in the textile industry due to their ability to decolorize dyes, modify fabric surfaces, and bleach textiles. Identifying a laccase with both high thermal stability and alkali tolerance suitable for textile applications presents a significant challenge. A novel alkaline laccase, LacCT, was discovered from Caldalkalibacillus thermarum and successfully expressed it in Escherichia coli. LacCT displayed optimal activity at 65°C and maintained high stability across a pH range of 6.0-10.0, with an optimal pH of 7.5. Through rational design, the thermal stability of the best variant, G190P/Q254Y/G336M/D510F (LacCT-11), was significantly enhanced, resulting in a half-life of 63.2 min at 60°C - 1.8 times longer than that of the wild type. This research introduces a promising new laccase with considerable potential for decolorizing textile wastewater and improving the ramie degumming process., (© 2024 Wiley‐VCH GmbH.)

Exploration of Pleurotus ostreatus as a biological agent in the degradation of persistent plastics like polyethylene, polystyrene, polyvinyl chloride, and polyethylene terephthalate, revealing a promising avenue toward mitigating the environmental impacts of plastic pollution. Leveraging the intrinsic enzymatic capabilities of this fungus, mainly its production of laccase, presents a sustainable and eco-friendly approach to breaking down complex polymer chains into less harmful constituents. This review focused on enhancements in the strain's efficiency through genetic engineering, optimized culture conditions, and enzyme immobilization to underscore the potential for scalability and practical application of this bioremediation process. The utilization of laccase from P. ostreatus in plastic waste management demonstrates a vital step forward in pursuing sustainable environmental solutions. By using the potential of fungal bioremediation, researchers can move closer to a future in which the adverse effects of plastic pollution are significantly mitigated, benefiting the health of our planet and future generations., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The industrial applications of enzymes are usually hindered by the high production cost, intricate reusability, and low stability in terms of thermal, pH, salt, and storage. Therefore, the de novo design of nanozymes that possess the enzyme mimicking biocatalytic functions sheds new light on this field. Here, we propose a facile one-pot synthesis approach to construct Cu-chelated polydopamine nanozymes (PDA-Cu NPs) that can not only catalyze the chromogenic reaction of 2,4-dichlorophenol (2,4-DP) and 4-aminoantipyrine (4-AP), but also present enhanced photothermal catalytic degradation for typical textile dyes. Compared with natural laccase, the designed mimic has higher affinity to the substrate of 2,4-DP with K m of 0.13 mM. Interestingly, PDA-Cu nanoparticles are stable under extreme conditions (temperature, ionic strength, storage), are reusable for 6 cycles with 97 % activity, and exhibit superior substrate universality. Furthermore, PDA-Cu nanozymes show a remarkable acceleration of the catalytic degradation of dyes, malachite green (MG) and methylene blue (MB), under near-infrared (NIR) laser irradiation. These findings offer a promising paradigm on developing novel nanozymes for biomedicine, catalysis, and environmental engineering., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: [Junbai Li reports financial support was provided by National Natural Science Foundation of China. Yi Jia reports financial support was provided by National Natural Science Foundation of China. Yi Jia reports financial support was provided by National Key Research and Development Program of China]., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Laccase is a multicopper enzyme that plays a unique role in bioremediation of environmental pollutants. Bacteria were isolated from hospital wastewater and screened for laccase production. The laccase production process condition was optimised, and the laccase obtained was characterised. The 16S rRNA molecular analysis conducted on the best laccase producer revealed a Bacillus sp. NU2 identified. The process conditions: pH5, 45°C, 100 rpm, 5% inoculum, and growth constituents v iz: tangerine peel and wheat bran agro-wastes, beef extract, ammonium persulfate, glucose, galactose, xylose, sorbitol, fructose carbon sources; and 4-aminophenol inducer optimally stimulated laccase production. The Bacillus sp. NU2 laccase was optimal at pH and temperature conditions of 8.0°C and 60°C, with a noteworthy pH and thermal stability observed. Furthermore, NU2 laccase showed a moderate/high tolerance and relative activity effect on various chemical inhibitors, halides and surfactant of triton x-100 (105 ± 0.92%), PMSF (107 ± 0.81%), and NaCl (94 ± 0.81%) at 1, 3, and 6 (mM) concentration. Additionally, NU2 laccase maintained a relative activity of 101%, 104%, and 102% for Mg 2+ , Zn 2+ , and Fe 3+ at 1, 3, and 6 mM respectively. Acetone and propanol significantly upregulated laccase activity at 114 ± 0.0008% and 118.24 ± 0.35 and also at 30 and 20 (%) concentrations. Conclusively, the tolerant effect of Bacillus sp. NU2 laccase in pH, temperature, inhibitors and organic solvents suggests its potential for biotechnological application and promotion of a greener environment.

The applications of natural laccases are greatly restricted because of their drawbacks like poor biostability, high costs, and low recovery efficiency. M/NC single atom nanozymes (M/NC SAzymes) are presenting as great substitutes due to their superior enzyme-like activity, excellent selectivity and high stability. In this work, inspired by the catalytic active center of natural enzyme, a biomimetic Fe/NC SAzyme (Fe-SAzyme) with O 2 -Fe-N 4 coordination is successfully developed, exhibiting excellent laccase-like activity. Compared with their natural counterpart, Fe-SAzyme has shown superior catalytic efficiency and excellent stability under a wide range of pH (3.0-9.0), temperature (4-80 °C) and NaCl strength (0-300 mm). Interestingly, density functional theory (DFT) calculations reveal that the high catalytic performance is attributed to the activation of O 2 by O 2 -Fe-N 4 sites, which weakened the O─O bonds in the oxygen-to-water oxidation pathway. Furthermore, Fe-SAzyme is successfully applied for efficient aflatoxin B 1 removal based on its robust laccase-like catalytic activity. This work provides a strategy for the rational design of laccase-like SAzymes, and the proposed catalytic mechanism will help to understand the coordination environment effect of SAzymes on laccase-like catalytic processes., (© 2024 Wiley‐VCH GmbH.)

Herein, a nanocomposite of Cu,Ce-containing phosphotungstates (Cu,Ce-PTs) with outstanding laccase-like activity was fabricated via a one-pot microwave-assisted hydrothermal method. Notably, it was discovered that both Fe 3+ and Cr 6+ could significantly enhance the electron transfer rates of Ce 3+ and Ce 4+ , along with generous Cu 2+ with high catalytic activity, thereby promoting the laccase-like activity of Cu,Ce-PTs. The proposed system can be used for the detection of Fe 3+ and Cr 6+ in a range of 0.667-333.33 μg/mL and 0.033-33.33 μg/mL with a low detection limit of 0.135 μg/mL and 0.0288 μg/mL, respectively. The proposed assay exhibits excellent reusability and selectivity and can be used in traditional Chinese medicine samples analysis., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Self-powered biosensors with high sensitivity have garnered significant interest for their potential applications in the realm of portable sensing. Herein, a self-powered biosensor with a novel signal amplification strategy was developed by integrating target-controlled release of mediator with an enzyme biofuel cell for the ultrasensitive detection of acetamiprid (ACE). Zeolitic imidazolate framework-67 was utilized as both a nanocontainer for capturing the electron mediator 2,2'-azidobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and a precursor for the synthesis of cobalt nanoparticles/nitrogen, sulfur-codoped carbon nanotubes (Co NPs/NS-CNTs), which were employed as the electrode material for constructing both the glucose oxidase-based bioanode and the laccase-based biocathode. The target analyte ACE can specifically bind to its aptamer, leading to the release of ABTS, which cyclically participates in the catalytic reaction of the biocathode, thereby amplifying the electrochemical signal. By leveraging the benefits of ABTS cyclic catalysis and the effective electrocatalysis of bioelectrodes based on Co NPs/NS-CNTs, the self-powered biosensor has a broad detection range of 0.1-1000 fM and a low detection limit of 25 aM toward ACE. The proposed signal amplification approach presents a promising strategy for enhancing sensitivity and enabling portable analysis in applications of food safety, environmental monitoring, and medical diagnostics., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Endocrine disruptors such as bisphenol A (BPA) adversely affect the environment and human health. Laccases are used for the efficient biodegradation of various persistent organic pollutants in an environmentally safe manner. However, the direct application of free laccases is generally hindered by short enzyme lifetimes, non-reusability, and the high cost of a single use. In this study, laccases were immobilized on a novel magnetic three-dimensional poly(ethylene glycol) diacrylate (PEGDA)-chitosan (CS) inverse opal hydrogel (LAC@MPEGDA@CS@IOH). The immobilized laccase showed significant improvement in the BPA degradation performance and superior storage stability compared with the free laccase. 91.1% of 100 mg/L BPA was removed by the LAC@MPEGDA@CS@IOH in 3 hr, whereas only 50.6% of BPA was removed by the same amount of the free laccase. Compared with the laccase, the outstanding BPA degradation efficiency of the LAC@MPEGDA@CS@IOH was maintained over a wider range of pH values and temperatures. Moreover, its relative activity of was maintained at 70.4% after 10 cycles, and the system performed well in actual water matrices. This efficient method for preparing immobilized laccases is simple and green, and it can be used to further develop ecofriendly biocatalysts to remove organic pollutants from wastewater., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier B.V.)

This study showcased the antibiotic degradation abilities of laccase and catalase-peroxidase from Bacillus ligniniphilus L1, an extremophile, against 18 common antibiotics using computationally guided approach. Molecular docking and simulation identified six enzyme-antibiotic complexes for laccase and four for catalase-peroxidase, demonstrating significant binding affinity and stability. Enzyme activity assays corroborated computational results, indicating both enzymes could degrade all tested antibiotics with varying efficiencies. L1 laccase outperformed commercial laccase against five antibiotics, notably vancomycin, levofloxacin, tobramycin, linezolid, and rifamycin, with enhanced degradation potential upon ABTS addition. Catalase-peroxidase from L1 exhibited superior degradation efficiency over commercial peroxidase against vancomycin, linezolid, tobramycin, and clindamycin. Overall, this study underscores the computational approach's utility in understanding enzyme-mediated antibiotic degradation, offering insights into environmental contaminant remediation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

Thin-layer chromatography (TLC) hyphenated to bioassays is a modern tool used for discovery of biologically active compounds from complex mixtures. The first bioautographic assay for detecting laccase inhibitors on a TLC plate was developed in this study. The on-plate reaction of laccase with colourless ABTS that renders the blue ABTS ∙+ radical was optimised. Combination of the enzymatic TLC-assay with a control TLC-assay, wherein ABTS ∙+ radical is chemically generated and then applied on the TLC, allowed to differentiate between the pure laccase inhibitor sodium azide and radical scavengers such as gallic and kojic acids. The limit of detection and quantification for the method were 54.9 and 166 ng of sodium azide respectively. The methodology was applied successfully to a recently discovered laccase inhibitor chemotype: hydrazones. A model hydrazone was compared with several hydrazones synthesized for this study. For the first time, laccase inhibitors separated on a TLC plate can be detected individually., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

A novel antibacterial film based on arabinoxylan (AX) was prepared by introducing ferulic acid (FA) to AX through a laccase-catalyzed procedure. The ferulic acid-arabinoxylan conjugates (FA-AX conjugates) have been characterized. Results showed that FA was successfully grafted onto the AX chains by covalent linkages, likely through nucleophilic addition between O-Ph in the phenolic hydroxyl group of FA, or through Michael addition via O-quinone intermediates. FA-AX conjugates showed improved crystallinity, thermal stability, and rheological properties, as well as a distinct surface morphology, compared with those of native AX. Moreover, FA-AX conjugates exhibited enhanced antibacterial ability against Staphylococcus aureus, Escherichia coli, Shewanella sp., and Pseudomonas sp. Mechanistic studies revealed that the enhanced antibacterial ability was due to the penetration of bacterial membrane by the phenolic molecule and the steric effect of FA-AX conjugates. The study demonstrates that the laccase-induced grafting method was effective in producing FA-AX conjugates; we have demonstrated its antibacterial ability and great potential in prolonging the shelf life of fresh seafood products., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)