RESUMEN
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 Fe3+ and Cr6+ could significantly enhance the electron transfer rates of Ce3+ and Ce4+, along with generous Cu2+ with high catalytic activity, thereby promoting the laccase-like activity of Cu,Ce-PTs. The proposed system can be used for the detection of Fe3+ and Cr6+ 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.
Asunto(s)
Cerio , Cromo , Colorimetría , Cobre , Hierro , Lacasa , Cobre/análisis , Cobre/química , Cromo/análisis , Colorimetría/métodos , Lacasa/metabolismo , Lacasa/química , Hierro/análisis , Hierro/química , Cerio/química , Límite de Detección , Ácido Fosfotúngstico/química , Nanocompuestos/química , CatálisisRESUMEN
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.
Asunto(s)
Compuestos de Bencidrilo , Enzimas Inmovilizadas , Lacasa , Fenoles , Polietilenglicoles , Contaminantes Químicos del Agua , Lacasa/química , Lacasa/metabolismo , Fenoles/química , Contaminantes Químicos del Agua/química , Enzimas Inmovilizadas/química , Enzimas Inmovilizadas/metabolismo , Polietilenglicoles/química , Quitosano/química , Hidrogeles/química , Biodegradación Ambiental , Disruptores Endocrinos/químicaRESUMEN
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 × 105 M-1 s-1 to 1.18 × 106 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 kcat. 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.
Asunto(s)
Bacillus subtilis , Dominio Catalítico , Lacasa , Simulación del Acoplamiento Molecular , Lacasa/metabolismo , Lacasa/genética , Lacasa/química , Bacillus subtilis/enzimología , Bacillus subtilis/genética , Estabilidad de Enzimas , Cinética , Ácidos Sulfónicos/metabolismo , Catálisis , BenzotiazolesRESUMEN
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 m2/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.
Asunto(s)
Ácidos Cafeicos , Enzimas Inmovilizadas , Lacasa , Estructuras Metalorgánicas , Lacasa/química , Lacasa/metabolismo , Estructuras Metalorgánicas/química , Enzimas Inmovilizadas/química , Enzimas Inmovilizadas/metabolismo , Ácidos Cafeicos/química , Ácidos Cafeicos/metabolismo , Estabilidad de Enzimas , Cobre/química , Porosidad , Cinética , Cromo/química , Adsorción , Oxidación-Reducción , Antioxidantes/químicaRESUMEN
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.
Asunto(s)
Líquidos Iónicos , Lacasa , Simulación de Dinámica Molecular , Lacasa/química , Lacasa/metabolismo , Líquidos Iónicos/química , Trametes/enzimología , Solventes/química , Colina/química , PolyporaceaeRESUMEN
In angiosperms, seed size is a critical trait that is influenced by the complex interplay between the endosperm and seed coat. The HAIKU (IKU) pathway, involving the transcription factor WRKY10, plays a crucial role in regulating seed size in Arabidopsis thaliana. However, the downstream targets of WRKY10 and their roles in seed size determination remain largely unexplored. Here, we identified LACCASE2 (LAC2), a laccase gene involved in lignin biosynthesis, as a new downstream target of WRKY10. We observed that the expression of LAC2 was upregulated in the mini3 mutant, which is defective in WRKY10. We demonstrated that WRKY10 directly binds to the promoter of miR397a, activating its expression. miR397a, in turn, represses the expression of LAC2. Genetic analyses revealed that a mutation in LAC2 or overexpression of miR397a partially rescued the small seed phenotype of the MINISEED3 (MINI3) mutant mini3. Conversely, the overexpression of LAC2 in the wild type led to a decrease in seed size. These findings suggest that LAC2 functions as a negative regulator of seed size, and its expression is modulated by WRKY10 through miR397a. Our study uncovers a novel WRKY10-miR397a-LAC2 pathway that regulates seed size in Arabidopsis, providing new insights into the complex regulatory network governing seed development in plants.
Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Regulación de la Expresión Génica de las Plantas , MicroARNs , Semillas , Factores de Transcripción , Arabidopsis/genética , Arabidopsis/crecimiento & desarrollo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Semillas/genética , Semillas/crecimiento & desarrollo , MicroARNs/genética , MicroARNs/metabolismo , Lacasa/genética , Lacasa/metabolismo , Regiones Promotoras Genéticas , Lignina/metabolismo , Lignina/biosíntesis , Lignina/genética , MutaciónRESUMEN
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.
Asunto(s)
Colorimetría , Epinefrina , Hierro , Lacasa , Lacasa/química , Lacasa/metabolismo , Colorimetría/métodos , Epinefrina/análisis , Hierro/química , Espectrometría de Fluorescencia , Límite de Detección , Nanoestructuras/química , Oxidación-Reducción , Fluorescencia , MicroondasRESUMEN
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 Cu2+ 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.
Asunto(s)
Aminofenoles , Bencimidazoles , Colorimetría , Cobre , Lacasa , Lacasa/química , Lacasa/metabolismo , Colorimetría/métodos , Cobre/química , Aminofenoles/química , Aminofenoles/análisis , Bencimidazoles/química , IsomerismoRESUMEN
Recently, prokaryotic laccases from lactic acid bacteria (LAB), which can degrade biogenic amines, were discovered. A laccase enzyme has been cloned from Oenococcus oeni, a very important LAB in winemaking, and it has been expressed in Escherichia coli. This enzyme has similar characteristics to those previously isolated from LAB as the ability to oxidize canonical substrates such as 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 2,6-dimethoxyphenol (2,6-DMP), and potassium ferrocyanide K4[Fe(CN6)], and non-conventional substrates as biogenic amines. However, it presents some distinctiveness, the most characteristic being its psychrophilic behaviour, not seen before among these enzymes. Psychrophilic enzymes capable of efficient catalysis at low temperatures are of great interest due to their potential applications in various biotechnological processes. In this study, we report the discovery and characterization of a new psychrophilic laccase, a multicopper oxidase (MCO), from the bacterium Oenococcus oeni. The psychrophilic laccase gene, designated as LcOe 229, was identified through the genomic analysis of O. oeni, a Gram-positive bacterium commonly found in wine fermentation. The gene was successfully cloned and heterologously expressed in Escherichia coli, and the recombinant enzyme was purified to homogeneity. Biochemical characterization of the psychrophilic laccase revealed its optimal activity at low temperatures, with a peak at 10 °C. To our knowledge, this is the lowest optimum temperature described so far for laccases. Furthermore, the psychrophilic laccase demonstrated remarkable stability and activity at low pH (optimum pH 2.5 for ABTS), suggesting its potential for diverse biotechnological applications. The kinetic properties of LcOe 229 were determined, revealing a high catalytic efficiency (kcat/Km) for several substrates at low temperatures. This exceptional cold adaptation of LcOe 229 indicates its potential as a biocatalyst in cold environments or applications requiring low-temperature processes. The crystal structure of the psychrophilic laccase was determined using X-ray crystallography demonstrating structural features similar to other LAB laccases, such as an extended N-terminal and an extended C-terminal end, with the latter containing a disulphide bond. Also, the structure shows two Met residues at the entrance of the T1Cu site, common in LAB laccases, which we suggest could be involved in substrate binding, thus expanding the substrate-binding pocket for laccases. A structural comparison of LcOe 229 with Antarctic laccases has not revealed specific features assigned to cold-active laccases versus mesophilic. Thus, further investigation of this psychrophilic laccase and its engineering could lead to enhanced cold-active enzymes with improved properties for future biotechnological applications. Overall, the discovery of this novel psychrophilic laccase from O. oeni expands our understanding of cold-adapted enzymes and presents new opportunities for their industrial applications in cold environments.
Asunto(s)
Lacasa , Oenococcus , Oenococcus/enzimología , Oenococcus/genética , Lacasa/metabolismo , Lacasa/genética , Lacasa/química , Especificidad por Sustrato , Proteínas Bacterianas/metabolismo , Proteínas Bacterianas/genética , Proteínas Bacterianas/química , Secuencia de Aminoácidos , Escherichia coli/genética , Escherichia coli/metabolismo , Clonación Molecular , Cinética , Modelos Moleculares , Cristalografía por Rayos X , Concentración de Iones de HidrógenoRESUMEN
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.
Asunto(s)
Lacasa , Tetraciclinas , Lacasa/genética , Lacasa/metabolismo , Lacasa/química , Tetraciclinas/química , Tetraciclinas/metabolismo , Concentración de Iones de Hidrógeno , Temperatura , Biodegradación Ambiental , Evolución Molecular Dirigida , Mutación , Cinética , Hongos/enzimología , Hongos/genética , Oxidación-ReducciónRESUMEN
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 Zn2+ instead of the typically observed Cu2+ found in other laccases, and metal-ion substitution experiments raised the catalytic efficiency to 3-fold when Zn2+ was replaced with Fe2+. 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.
Asunto(s)
Biodegradación Ambiental , Frío , Lacasa , Lacasa/química , Lacasa/metabolismo , Concentración de Iones de Hidrógeno , Estabilidad de Enzimas , Bacillaceae/enzimología , Fenoles/metabolismo , Fenoles/química , Clonación Molecular , Contaminantes Ambientales/metabolismo , Contaminantes Ambientales/química , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/química , CinéticaRESUMEN
A promising water treatment technology involves inducing the polymerization of organic pollutants to form corresponding polymers, enabling rapid, efficient, and low CO2 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.
Asunto(s)
Cobre , Lacasa , Polimerizacion , Tetraciclinas , Tiadiazoles , Contaminantes Químicos del Agua , Purificación del Agua , Lacasa/química , Lacasa/metabolismo , Tetraciclinas/química , Contaminantes Químicos del Agua/química , Cobre/química , Ligandos , Purificación del Agua/métodos , Tiadiazoles/química , Antibacterianos/química , Nanoestructuras/químicaRESUMEN
The shift towards a circular economy, where waste generation is minimized through waste re-use and the development of valorization strategies, is crucial for the establishment of a low carbon, sustainable, and resource-efficient economy. However, there is a lack of strategies for re-using and valorizing specific types of waste, particularly those containing naturally occurring radioactive materials (NORM), despite the prevalence of industrial activities that produce such waste due to their chemical and radiological hazards. Living organisms, including fungi, are valuable sources of bioactive compounds with various industrial applications. In this study, we assessed the growth and metabolic profile changes of three white rot fungi species in response to low concentrations of a uranium mine effluent containing NORM and metals to explore their potential for producing biotechnologically relevant bioactive compounds. The growth rate was assessed in three different culture media, with and without the uranium mine effluent (1% V/V)), and the metabolic profile was analyzed using FTIR-ATR spectroscopy. Results suggested an improvement in growth rates in media containing the uranium mine effluent, although not statistically significant. T. versicolor showed promise in terms of bioactive compound production. The production of droplets during growth experiments and significant metabolic changes, associated with the production of bioactive compounds like laccase, melanin, and oxalic acid, were observed in T. versicolor grown in mYEPDA with the uranium mine effluent. These findings present new research opportunities for utilizing waste to enhance the biotechnological production of industrially relevant bioactive compounds and promote the development of circular economy strategies for re-using and valorizing NORM-containing waste.
Asunto(s)
Residuos Industriales , Minería , Uranio , Uranio/metabolismo , Biodegradación Ambiental , Lacasa/metabolismoRESUMEN
Improper waste disposal or inadequate wastewater treatment can result in pharmaceuticals reaching water bodies, posing environmental hazards. In this study, crude extracts containing the laccase enzyme from Pleurotus florida, Pleurotus eryngii, and Pleurotus sajor caju were used to degrade the fluoroquinolone antibiotics (FQs) levofloxacin (LEV), norfloxacin (NOR), ciprofloxacin (CIP), ofloxacin (OFL), and enrofloxacin (ENR) in aqueous solutions. The results for the fungi derived laccase extracts were compared with those obtained using commercially sourced laccase. Proteomics analysis of the crude extracts confirmed the presence of laccase enzyme across all three tested species, with proteins matching those found in Trametes versicolor and Pleurotus ostreatus. In vivo studies were conducted using species pure lines of fungal whole cells. The highest degradation efficiency observed was 77.7% for LEV in the presence of P. sajor caju after 25 days of treatment. Degradation efficiencies ranged from approximately 60-72% for P. florida, 45-76% for P. eryngii, and 47-78% for P. sajor caju. A series of in vitro experiments were also conducted using crude extracts from the three species and outcomes compared with those obtained when commercial laccase was used confirmed laccase as the enzyme responsible for antibiotic removal. The degradation efficiencies in vitro surpassed those measured in vivo, ranging from approximately 91-98% for commercial laccase, 77-92% for P. florida, 76-92% for P. eryngii, and 78-88% for P. sajor caju. Liquid chromatography-high-resolution mass spectrometry (LC-MS/MS) identified the degradation products, indicating a consistent enzymatic degradation pathway targeting the piperazine moiety common to all tested FQs, irrespective of the initial antibiotic structure. Phytoplankton toxicity studies with Dunaliella tertiolecta were performed to aid in understanding the impact of emerging contaminants on ecosystems, and by-products were analysed for ecotoxicity to assess treatment efficacy. Laccase-mediated enzymatic oxidation shows promising results in reducing algal toxicity, notably with Pleurotus eryngii extract achieving a 97.7% decrease for CIP and a 90% decrease for LEV. These findings suggest the potential of these naturally sourced extracts in mitigating antibiotic contamination in aquatic ecosystems.
Asunto(s)
Antibacterianos , Biodegradación Ambiental , Fluoroquinolonas , Lacasa , Pleurotus , Contaminantes Químicos del Agua , Lacasa/metabolismo , Pleurotus/metabolismo , Fluoroquinolonas/metabolismo , Fluoroquinolonas/toxicidad , Antibacterianos/toxicidad , Contaminantes Químicos del Agua/metabolismo , Contaminantes Químicos del Agua/toxicidad , Aguas Residuales/químicaRESUMEN
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.
Asunto(s)
Compuestos de Bencidrilo , Enzimas Inmovilizadas , Lacasa , Fenoles , Dióxido de Silicio , Lacasa/química , Lacasa/metabolismo , Fenoles/química , Fenoles/metabolismo , Compuestos de Bencidrilo/química , Compuestos de Bencidrilo/metabolismo , Enzimas Inmovilizadas/química , Enzimas Inmovilizadas/metabolismo , Dióxido de Silicio/química , Adsorción , Biodegradación Ambiental , Biocatálisis , Propiedades de SuperficieRESUMEN
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.
Asunto(s)
Fibra de Algodón , Lacasa , Musa , Textiles , Musa/química , Lacasa/química , Lacasa/metabolismo , Poligalacturonasa/química , Poligalacturonasa/metabolismo , Amilasas/metabolismo , Amilasas/química , Glicósido Hidrolasas/metabolismo , Glicósido Hidrolasas/química , Celulosa/químicaRESUMEN
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 m2.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.
Asunto(s)
Enzimas Inmovilizadas , Tecnología Química Verde , Lacasa , Nanopartículas de Magnetita , Contaminantes Químicos del Agua , Lacasa/química , Lacasa/metabolismo , Enzimas Inmovilizadas/química , Enzimas Inmovilizadas/metabolismo , Nanopartículas de Magnetita/química , Contaminantes Químicos del Agua/química , Tecnología Química Verde/métodos , Concentración de Iones de Hidrógeno , Aguas Residuales/química , Temperatura , Porosidad , Colorantes de Rosanilina/química , Estabilidad de Enzimas , Hierro/química , Purificación del Agua/métodos , MetagenomaRESUMEN
As a kind of aminoglycoside antibiotics, kanamycin (KAN) is widely applied to animal husbandry and aquaculture. However, the abuse of KAN causes the large-scale discharge of it into rivers, lakes and groundwater, which threatens environmental safety and human health. Therefore, it is imperative to develop a method that is applicable to detect KAN in an efficient and accurate way. The colorimetric method based on enzymes provides a feasible solution for the detection of organic pollutants. However, the extensive application of natural enzymes is constrained by high cost and low stability. Herein, a polyoxometalate-based nanozyme, namely [H7SiW9V3O40(DPA)3]·4H2O (SiW9V3/DPA) (DPA = dipyridylamine), is synthesized. As a low-cost nanozyme with high stability compared to natural enzymes, SiW9V3/DPA performs well in laccase-mimicking activity. It can be used to induce chromogenic reaction between 2,4-dichlorophenol (2,4-DP) and 4-aminoantipyrine (4-AP), which generates red products. With the addition of KAN, the color fades. That is to say, KAN can be detected with colorimetric assay in the concentration range 0.1 to 100 µM with high selectivity and low limit of detection (LOD) of 6.28 µM. Moreover, SiW9V3/DPA is applied to KAN detection in lake and river water and milk with satisfactory results. To sum up, polyoxometalate-based nanozyme is expected to provide a promising solution to the detection of organic pollutants in the aquatic environment.
Asunto(s)
Colorimetría , Kanamicina , Lacasa , Ampirona/química , Materiales Biomiméticos/química , Colorimetría/métodos , Kanamicina/análisis , Lacasa/química , Lacasa/metabolismo , Límite de Detección , Compuestos de Tungsteno/química , Contaminantes Químicos del Agua/análisisRESUMEN
To achieve efficient dye degradation, we reported a visible light-driven biomass photo-enzyme coupled system, which was constructed by assembling g-C3N4 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-C3N4 could be stably interspersed, and MOF grew g-C3N4/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.
Asunto(s)
Celulosa , Colorantes , Lacasa , Luz , Celulosa/química , Celulosa/metabolismo , Colorantes/química , Lacasa/metabolismo , Lacasa/química , Azul de Metileno/química , Biodegradación Ambiental , Enzimas Inmovilizadas/química , Enzimas Inmovilizadas/metabolismo , Bacterias , Estructuras Metalorgánicas/química , Contaminantes Químicos del Agua , Catálisis , Rodaminas/químicaRESUMEN
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 [N10111][Br] and 1-decyl-3-methylimidazolium chloride [C10mim][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 [N10111][Br] and [C10mim][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 [N10111][Br] and [C10mim][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 [N10111]+ and [C10mim]+ with laccase; in addition, the [Dec]- anion, compared to [Br]- and [Cl]- has a much greater tendency to bind with the enzyme residues.