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Antibiotics are one of emerging pollutants generally emitted from livestock production and the food industry to the environment. The presence of this pollutant could initiate the development of resistant bacteria that can be fatal to human health. The degradation of antibiotics using enzymes or microbe could be an alternative because the residue or intermediate product is less harmful than of the conventional method. This research aims to support a preliminary study of the degradation of antibiotics using enzyme through molecular docking via Molecular Operating Environment software and molecular dynamics (MD) study via CABSFLEX 2.0 and WebGro macromolecular simulations. The molecular docking of the laccase-chloramphenicol complex has low binding energies of approximately -8.1350 and -8.2290 kcal/mol for both rigid and flexible methods, respectively, indicating that the formation of the complex is advantegous. MD simulation further revealed a decrease in rigidity after the interaction with the ligand. Hydrogen bonding analysis indicated up to five hydrogen bonds in the complex, underscoring the robustness of the enzyme--ligand interaction. These results collectively contribute to our understanding of the efficacy of enzyme-mediated antibiotic degradation and emphasize the potential for this approach to mitigate environmental and health concerns associated with antibiotic pollution. [ABSTRACT FROM AUTHOR]

Although plastic is very useful in modern life, its widespread use could impair human sustainability. Improper plastic waste management generates greenhouse gases and harmful waste. Plastics and its associated by-products, such as microplastics, accumulate on land and in the oceans causing harm to human and ecological health. An environmentally friendly solution, such as enzymes-mediated biocatalytic depolymerization, is required for efficient management of the large amount of waste generated around the world. Actinomycetes are less explored for commercial biodegradation processes but have attracted attention since they constitute a significant proportion of the soil and aquatic flora and because of their ability to degrade complex materials. This study involves identification of laccase-producing marine actinomycetes and examining the possibility of accelerating the rate of biodegradation of polyethylene by treating with laccase enzyme. The polyethylene test material treated with laccase enzyme for 30 days shows 9.36 percent rate of biodegradation, which was six times higher than the rate of biodegradation of an untreated one. The change in the chemical structure of the polyethylene was studied using Fourier transform infrared spectroscopy. After treatment with laccase enzyme, the carbonyl index of the polyethylene test material increased to 1.25 indicating that the polymer was oxidized, and post biodegradation study showed that the carbonyl index decreased to 0.66 which confirms the concept that oxidized polymer was utilized by the microorganisms. The laccase-producing isolate A-09 showed 99 percent identity as Streptomyces rubiginosus based on molecular fingerprinting.

The antibacterial agent can be extracted from plants, animals, and microorganisms such as fungi. The potential antibacterial activity of laccase derived from fungi remains limited in current reports. This study aimed to investigate the characteristics of laccase from Indonesian white rot fungi (WRF) and explore its potential as an antibacterial agent. The laccases were produced by Trametes hirsuta D7, Trametes hirsuta EDN 082, Leiotrametes menziesii BRB 73, and Lentinus sajor-caju BRB 12 using oil palm empty fruit bunch as a substrate. The results showed that the Indonesian WRF tested produced brownish-yellow laccase. FTIR analysis demonstrated similar peak patterns but distinct absorption intensities among the laccases. Trametes hirsuta D7 gained 0.044 U/ml of the greatest laccase activity. Laccase, with minimal activity of 0.001 U/ml–0.026 U/ml, suppressed the propagation of Propionibacterium acnes and Staphylococcus aureus. Escherichia coli and Pseudomonas aeruginosa could be inhibited by the laccase with a minimum activity of 0.002 U/ml–0.044 U/ml. However, S. aureus and E. coli showed the Minimum Bactericidal Concentration in the laccase activity range of 0.018 U/ml–0.308 U/ml. Gram-positive and Gramnegative bacteria grow more slowly when the laccase is present, supposed the laccase as a potential antibacterial agent. [ABSTRACT FROM AUTHOR]

The local isolate TY10 was derived from a soil sample that was polluted with oil in a previous investigation. The study focused on evaluating the isolate's capacity to manufacture the laccase enzyme. The Bacillus cereus isolate was identified based on the findings of morphological and biochemical testing, as well as the VITEK-2 tests. The synthesis of laccase by the Bacillus cereus TY10 isolate was assessed using qualitative and quantitative methods, with guaiacol serving as a substrate indicator. The qualitative investigation revealed that the local isolate TY10 exhibited a strong capacity for laccase enzyme production in the solid medium. Simultaneously, it was shown that the indigenous strain Bacillus cereus TY10 exhibited an enzyme activity of 0.98 units/ml when the broth of the indigenous strain was utilised in quantitative measurements for enzyme synthesis. The impact of different durations of incubation, pH values, and the current research focused on examining temperatures and their impact on the ability of a local entity Bacillus cereus TY10 Extract laccase enzyme by isolation. The study discovered that laccase production reached its peak of 1.61 Unit/ml occurred after 48 hours of incubation at 35°C, using a growth medium with a pH of 7. The crude laccase enzyme underwent a purification procedure consisting of three sequential steps: Ammonium sulphate precipitation and two gel filtration steps using Sephadex G-25 and G-100. This process resulted in a 6.52 times purification of the laccase enzyme, with a recovery rate of 90.65% and a specific activity of 39.98 unit/mg protein. All purification steps contributed to this outcome. [ABSTRACT FROM AUTHOR]

Lignin valorization to produce functionalized materials is challenging. This study harnessed the versatile properties of lignin through a grafting reaction involving the aryl hydroxyl group of alkali lignin (AL) and enzymatically modified-alkali lignin (EMAL) using Bacillus ligninphilus-derived laccase (Lacc) L1 and C. seriivinvornas-derived dye-decolorizing peroxidase (DyP) with keratin (K) amide group. This reaction was executed utilizing an eco-friendly solvent with the aim of generating thin films. A thorough investigation was conducted, focusing on grafting AL and EMAL onto K. The incorporation of EMAL into the films enhanced tensile strength (TS) (14.8±1.8 MPa) and elongation at break (EAB) (23.7±0.3 %). Additionally, it enhanced thermal stability, suppressed the proliferation of Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli), and mitigated oxidative stress. This study introduces a novel approach for lignin valorization, offering the potential to tailor mechanical properties, antibacterial and antioxidant properties of the final material, making it sustainable substitute for petroleum-based products.

An electrochemical biosensor for the bisphenol A determination was constructed onto a glassy carbon electrode modified with a hybrid nanostructure based on polypyrrole‐3‐carboxylic acid/Sb2O5/reduced graphene oxide and laccase enzyme. The hybrid nanostructure was characterized by X‐ray photoelectron spectroscopy (XPS), HR‐TEM, SEM microscopy, and electrochemical techniques. The biosensor displayed excellent response for bisphenol A determinations by differential pulse voltammetry, showing a theoretical detection limit of 9.9 nmol L−1 in the linear range of 0.1–1.0 μmol L−1. The biosensor demonstrated excellent selectivity in the determinations of bisphenol A in tap water without significant interference from other species, such as 17β‐estradiol, Estriol, Progesterone, Catechol, Hydroquinone, Ascorbic acid, and Dopamine. The biosensor also has presented an excellent performance in bisphenol A determinations in water, with recovery tax ranging from 99.6 to 101 %. Therefore, it can be used satisfactorily to detect bisphenol A in real samples. [ABSTRACT FROM AUTHOR]

Fungal laccases are promising for biotechnological applications, including bioremediation and dye biotransformation, due to their high redox potential and broad substrate specificity. However, current bioprospecting methods for identifying laccase-producing fungi can be challenging and time-consuming. For early detection, it was developed a three-step, multi-criteria weighting system that evaluates fungal strains based on: First, the biotransformation capacity of three dyes (i.e., Congo red, brilliant blue G-250, and malachite green), at three different pH values, and with a relative weighting supported for the redox potential of each colorant. The relative decolorization coefficient (RDC), used as th2e first classification criterion, expressed their potential performance. Second, under the same conditions, laccase activity was estimated by observing the different degrees of oxidation of a given substrate. The selection criterion was the relative oxidation coefficient (ROC). Finally, laccase activity was quantified in submerged fermentations using three inducers (i.e., loofah sponge, Tween 80, and veratyl alcohol). This multicriteria screening strategy evaluated sixteen isolated endophytic fungal strains from Otoba gracilipes. The system identified Beltraniopsis sp. ET-17 (at pH values of 5.00 and 5.50) as a promising strain for dye biotransformation, and Phlebia floridensis as the best laccase producer, achieving a high activity of 116 μmol min−1 L−1 with loofah sponge as an inducer. In-vitro testing confirmed the efficacy of P. floridensis , with 53.61 % decolorization of a dye mixture (brilliant blue-Congo red. ratio 1:1) after 15 days of incubation. Thus, with the proposed screening strategy it was possible to highlight two species of interest at an early bioprospecting stage on a Colombian native tree poorly explored. • Fungal endophyte screening based on two new quantitative coefficients. • Identification of strains with potential for remediation of dyed water by laccase. • Weighted decolorization coefficient based on the oxidation potential of dyes. • Phlebia floridensis with the ability to produce laccase at different pHs. • Beltraniopsis sp. for the first time related to the ability to decolorize. [ABSTRACT FROM AUTHOR]

This study set out to screen 36 common plants which have the greatest level of laccase enzyme activity. It revealed that the enzymatic activity of fenugreek seeds was the highest in comparison with other plants. The optimal enzyme-specific activity was 5340.38 units per milligram protein which were obtained by extracting the enzyme with a sodium phosphate buffer at a concentration of 0.02 M and pH 8.0, at a ratio of 1:40 (weight to volume), and extracting time of 210 minutes. The enzyme yield was 27.6% after extraction and purification by gel filtration using Sephacryl S-3 after 1.01 purification fold. The optimum circumstances for enzymatic activity and stability were found by using 0.1 M sodium acetate as a buffer at pH 5. Also, the maximal activity and stability of purified laccase was obtained at 20°C for 15 min by using o-tolidine as a substrate. This research sheds light on how to isolate and characterize the laccase enzyme, an important biochemical with numerous biotechnological and technological uses through fenugreek seeds as a source of the laccase. [ABSTRACT FROM AUTHOR]

Pharmaceuticals are often found in municipal wastewater due to human excretion and disposal of drugs into sewerage systems. Conventional wastewater treatment plants were not designed for pharmaceutical removal and, hence, pharmaceutical concentrations ranging from ng L−1 to μg L−1 are often detected in treated wastewater, with additional treatment required for full removal. This study has investigated the potential of Trametes versicolour laccase enzyme and 2,2'-azino-bis-(3-ethyl-benzthiazoline-6-sulphonic acid) diammonium salt (ABTS) mediator system to degrade sulfamethoxazole, trimethoprim, metronidazole and phenytoin. The best degradation was observed at pH 5 for both sulfamethoxazole (97% in 12 hours) and trimethoprim (44% in 168 hours), using an initial micropollutant concentration of 100 µM, an enzymatic activity between 110–115 U L−1, and an ABTS concentration of 200 µM. Phenytoin and metronidazole were not degraded. Deamination followed by hydroxylation led to the formation of the two major sulfamethoxazole transformation products (TPs), whilst hydroxylation and hydroxylation/demethylation mechanisms formed the majority of the trimethoprim TPs. The sulfamethoxazole and trimethoprim TPs observed from the laccase-ABTS system were similar to the TPs obtained from degradation processes such as advanced oxidation or photodegradation. The laccase-ABTS system shows promise for control of emerging contaminants containing electron donating groups (such as amines and methoxy groups) on aromatic rings in wastewater systems. [ABSTRACT FROM AUTHOR]

The present work is an attempt to study the effect of different surface treatments of flax fiber on the mechanical properties of the natural fiber reinforced natural rubber (NR) composites. In this study, flax fiber was chopped to 1, 1.25, and 1.5 cm in length and mixed with NR in two roll mill. The composite of 20%, 30%, 40%, and 50% fiber loading was prepared from each fiber length. Tensile analysis showed that a 1.25 cm fiber length composite of volume 40% has higher tensile strength compared to others. Hence, this optimized the fiber length and loading has opted for further study. Flax fiber was treated with NaOH and laccase and reinforced into an NR matrix. Properties like tensile strength, hardness, relative density, water diffusion, scanning electron microscope (SEM) and Fourier‐transform infrared spectroscopy (FTIR) for surface treated and untreated natural fiber‐reinforced NR composites have been investigated and compared. The reduction in the hydrophilic characteristics of the NaOH and laccase treated fiber was evident from FTIR analysis and increase in the crystallinity index of the fiber depicted by X‐ray diffraction (XRD) results. SEM analysis showed the enhanced interfacial interaction of treated flax fiber NR composite compared to untreated composite due to the removal of non‐cellulosic contents in fiber and an increase in the surface roughness after treatments. Further, an increase of 9% and 27.4% in tensile and tear strength was found in NaOH treated flax fiber reinforced NR composite. [ABSTRACT FROM AUTHOR]

In this study, the simultaneous enzymatic decolorization of reactive blue 221 (RB221) and the performance of different electrode carbon nanotube (CNT)-modified/unmodified carbon graphite cathodes were investigated in a dual-chamber Microbial Fuel Cell (MFC) at a permanent temperature of 25 °C. The maximum power density and maximum voltage increased by approximately 13.6% and 50%, respectively, when using the CNT-modified carbon graphite electrode as the cathode. A suspended laccase enzyme was utilized in the cathode compartment for dye decolorization. In the absence of the dye, laccase caused an increase in power density to about 28%. In addition, this research revealed that an initial dye concentration of 80 mg/L simultaneously resulted in an enzymatic decolorization efficiency of 73.4% in the cathode chamber and 82.3% chemical oxygen demand (COD) removal of sucrose in the anode chamber. Finally, this study substantiates the fact that an MFC equipped with a CNT-modified carbon graphite electrode can be used for bioelectricity generation and effective dye removal. [ABSTRACT FROM AUTHOR]

Abstract Use of enzyme for extraction of nanocellulose from sugarcane bagasse is greener alternative. Literature indicates that effectiveness of these enzymes can be improved by auxiliary enzymes or mediators. In the current study, extraction of nanocellulose using laccase with these moderators, auxiliary enzyme glucose oxidase and mediator molecule, ABTS [2,2′-azinobis(3-ethylbenzthiazoline-6-sulfonate)] individually was done. Cellulose and lignin content, FT-IR, TGA and DSC analysis, XRD, SEM and PSA were done. Enzyme moderators improved the performance of laccase in lignin degradation. Lignin and cellulose content, crystallinity were used as parameters to optimize the concentrations, which was found to be ABTS (at 1.4 mM) and glucose oxidase (at 0.15 mg ml−1). At the optimal concentration, nanocellulose was extracted. Properties of nanocellulose obtained from both routes were compared. Size analysis revealed 339 nm and 636 nm for nanocellulose obtained with glucose oxidase and ABTS, respectively. Defibrillation was better in the case of the former one as seen from SEM. Graphical Abstract

Laccase enzymes have been used widely in industrial fields such as textile, pulp, paper, food, cosmetic, and pharmaceutical industries. Laccase is used in toothpaste, mouthwash, deodorants, and soaps in personal care products. Previously, laccase enzymes had never been used for formulating hand sanitizer gel. This study aimed to determine the effect of the laccase enzyme on the physicochemical properties and the antibacterial potential of the hand sanitizer gel against pathogenic bacteria. Laccase enzyme was produced through fermentation using the fungus Trametes hirsuta EDN 082 with an activity of 0.032 U/mL. Hand sanitizer gel was made with the addition of laccase enzyme with varying concentrations of 4%, 7%, and 10% (v/v). The physicochemical test included organoleptic tests, pH evaluation, gel spreadability, and viscosity. The antibacterial was tested by the palm swab method. The gel physicochemical characteristics showed that the more laccase enzyme added, the more yellow the color produced, the less thick the shape, the wider the gel spreadability, and the lower the viscosity. The obtained pH ranged from 7.4 to 7.6. The best formulation of the hand sanitizer gel was achieved with the addition of a 7% (v/v) laccase enzyme. This formulation can reduce the number of bacteria colonies of Staphylococcus aureus and Escherichia coli on the palms with effectiveness above 95%. The laccase enzyme can be used as an active ingredient and antibacterial agent in the formulation of hand sanitizers.

Celiac disease is the most common disease caused by gluten consumption and the only way to prevent it is to use gluten -free foods. The aim of this study was to optimization the formulation of gluten -free bread based on quinoa flour, laccase enzyme, and xanthan gum. For this purpose, the sensory properties and texture of bread under the influence of independent variables including quinoa flour (0 - 50%), xanthan gum (0 -0.5%), and laccase enzyme (0 -2 units of enzyme activity per gram of flour (U/g) were evaluated using the response level method based on the central composite design. Then some qualitative characteristics of gluten -free bread sample in optimal conditions were compared with the control sample (gluten -free bread containing rice and corn flours without quinoa flour, laccase enzyme, and xanthan gum) for 7 days of storage. The results showed that quinoa flour and laccase enzyme had a significant effect on sensory properties including crust color, porosity, taste, aroma, firmness, and overall acceptibility(p<0.05) of breads. While the effect of quadratic level of gum on overall acceptibilityas well as the interaction of laccase enzyme and xanthan gum on bread firmness was significant (p<0.05). The optimal bread formulation consisted of 40% quinoa flour, 0.46% xanthan gum, and 2 U/g laccase enzyme. Comparison of the gluten - free optimal sample with the control gluten -free sample showed that the enthalpy and peak temperature of the control bread was higher than the optimal bread, which indicates more staleness. In terms of textural properties and sensory evaluation, the optimal sample was significantly better than the control sample. However, in terms of L* color indice, the control sample showed higher values (p<0.05 ) . [ABSTRACT FROM AUTHOR]

Predicting the dynamic response of key processes that take place in industrial biochemical systems such as the measurement of operating parameters by means of biosensors, before the biosensors themselves are prototyped, is of utmost importance. The advantages of performing mathematical modeling of biosensor systems in their development stages include cost reduction, easier response tuning and faster performance optimization. In most cases, the mathematical models for enzyme kinetics depend on multiple parameters. Finding the numerical values of such parameters usually requires carrying out a vast number of experiments, which is time intensive, expensive and involves the usage of specialized laboratory equipment. This work proposes the utilization of genetic algorithms as an alternative methodology for kinetic model parameter estimation of the oxidation of phenol in water, catalyzed by the laccase enzyme. The corresponding kinetics mathematical model of the oxidation reaction is used as a case study, to compare the results obtained using the genetic algorithms approach proposed with those found in the literature. The algorithm estimated the values of several parameters of the model, such as reaction rate constants, rate constant of transformation of oxygen by the electrode and stoichiometric coefficient, among others. The results found in this investigation by means of genetic algorithms show an agreement of 91%–99% with the data available in the literature. This approach also proved to be more accurate than the basic polynomial regression estimation method, which is commonly used and was implemented for comparison purposes. The proposed technique for parameters estimation in enzyme reaction models enabled the design of a phenol biosensor for concentrations ranging from 5 to 30 ppm. This technique has a high potential of application in the biosensor industry because of its cost savings, high speed and good accuracy. [ABSTRACT FROM AUTHOR]

Use of nanoparticles (NPs) in several commercial products has led to emergence of novel contaminants of air, soil and water bodies. The NPs may exhibit greater ecotoxicity due to nano-scale dependent properties over their bulk counterparts. The present investigation explores the effect of in vitro supplementation of TiO2, silica and silver NPs on radial growth and ultrastructural changes in the hyphae and spores of two mushroom genera, Ganoderma lucidum and Volvariella volvaceae. A concentration dependent decrease in radial growth on NP amended potato dextrose agar medium was recorded. However, in comparison to control, there was decrease in radial diameter on supplementation with TiO2 NPs while an increase was recorded for silica and silver NPs amendments as compared to their bulk salts at same concentrations after 48 h of incubation. Optical microscopy studies showed decrease in the number of spores while increase in spore diameter and thinning of hyphal diameter on NPs supplementation. Scanning electron microscopy analysis of fungal growth showed presence of deflated and oblong spores in two fruiting strains of Ganoderma while Volvariella exhibited decreased sporulation. Further, hyphal thinning and branching was recorded in response to NP amendments in both the test mushrooms. Enhancement of protein content was observed on NP compared to bulk supplementation for all cultures, concentrations and hours of incubation except for TiO2 NPs. Likewise, bulk and NP supplementations (at 100 mg L−1) resulted in enhanced laccase activity with occurrence of laccase specific protein bands on SDS-PAGE analysis.

Oral malodor negatively impacts a person's quality of life and may affect up to 50% of the population. The aim of this randomized, placebo and no-product controlled, evaluator-blind, proof-of-concept study was to evaluate the effectiveness and safety of the single use of two experimental lozenges containing the laccase enzyme and green coffee extract (with and without flavor) in reducing intrinsic oral malodor. Following 12-16 h of avoidance of oral hygiene,156 generally healthy subjects presented at screening and baseline visits with a mean organoleptic odor intensity (OI) score of ⩾2 and an OralChroma TM reading of ⩾125 parts per billion (ppb) hydrogen sulfide (H 2 S) gas and were randomly assigned to receive either one of the two experimental lozenges, a placebo lozenge, or no-product. Following the supervised use of the assigned products, subjects' oral malodor was evaluated using OI assessments and OralChroma TM measurement for volatile sulfur compounds (VSCs) immediately following product use (approximately 5 min), and at 30 min, 1 h, 2 h, 3 h and 4 h. The two experimental lozenges, with and without flavor, showed significant reductions in OI scores compared with the placebo and no-product groups at all time points ( p < 0.001). At 5 min post-product use, the experimental lozenges, with and without flavor, were significantly better than the no-product group in reducing the VSCs ( p < 0.04). The results of individual VSC components (hydrogen sulfide, methyl mercaptan and dimethyl sulfide) were variable; both experimental lozenges notably reduced hydrogen sulfide and methyl mercaptan levels in most post-use assessments. Four minor adverse events were reported, none of which were directly linked to the product. In conclusion, the experimental lozenges, whether flavored or not, were safe and effective in reducing oral malodor over a span of 4 h, based on organoleptic OI scores.Clinical Trial No: NCT05950529., (Creative Commons Attribution license.)

Use of enzyme for extraction of nanocellulose from sugarcane bagasse is greener alternative. Literature indicates that effectiveness of these enzymes can be improved by auxiliary enzymes or mediators. In the current study, extraction of nanocellulose using laccase with these moderators, auxiliary enzyme glucose oxidase and mediator molecule, ABTS [2,2′-azinobis(3-ethylbenzthiazoline-6-sulfonate)] individually was done. Cellulose and lignin content, FT-IR, TGA and DSC analysis, XRD, SEM and PSA were done. Enzyme moderators improved the performance of laccase in lignin degradation. Lignin and cellulose content, crystallinity were used as parameters to optimize the concentrations, which was found to be ABTS (at 1.4 mM) and glucose oxidase (at 0.15 mg ml−1). At the optimal concentration, nanocellulose was extracted. Properties of nanocellulose obtained from both routes were compared. Size analysis revealed 339 nm and 636 nm for nanocellulose obtained with glucose oxidase and ABTS, respectively. Defibrillation was better in the case of the former one as seen from SEM. [ABSTRACT FROM AUTHOR]

Background: : Lead (Pb) is an important environmental pollutants that play a significant role in increasing the stability of some other pollutants by changing the microbial profile of the soil. Bacillus subtilis WPI is an abundant bacteria existing in wastewater. Because of laccase enzyme in this bacterium, the decomposition process of aromatic pollutants in wastewaters can be facilitated. We aimed to investigate the effect of different Pb concentrations on B. subtilis growth and biological activity of laccase enzyme in B. subtilis WPI. Material and Methods: B. subtilis WPI was isolated from the paper mill industrial wastewater of Hormozgan, Iran, from March to August 2017. After purification, the growth trend of B. subtilis WPI as well as the activity of laccase enzyme in different concentrations of Pb was investigated based on kinetic method. Results: Bacterial growth at Pb concentration of 400 mg/L reduced in a dose-dependent manner, and this decrease was significant at concentrations of 300 and 400 mg/L (P < 0.001). The level of laccase enzyme activity in the lead concentration range of 20-160 mg/L also reduced in a dose-dependent manner, which implied that the highest decrease was observed at lead concentration of 160 mg/L (P < 0.01). Our findings showed that there was no significant change in bacterial growth in lead concentration range of 20-200 mg/L, while a significant change was observed in the activity of laccase enzyme in the mentioned concentration range. Conclusion: Therefore, it seems that this reduction in enzyme activity can indirectly increase the stability of aromatic oil pollutants in the environment.

Introduction: One of the important environmental problems in the international community is contamination with heavy metals from industrial development. Not only do these elements threaten human health but they also make changes in the natural state of the ecosystem. The purpose of this study was to investigate the effect of the heavy arsenic element on lactate enzyme activity in the Bacillus subtilis bacteria. Materials & Methods: Bacillus subtilis bacteria were isolated from the wastewater of paper and pasteboard industry of Hormozgan province from a depth of 51 cm below the surface of the soil and the strain was subjected to biochemical and morphological tests for screening. After determining the optimum growth conditions, the activity of the bacteria laccase enzyme in different concentrations of arsenic was measured from (5, 10, 15, and 20 mg.) was measured. The enzymatic activity of the strains was measured by the kinetic method at each concentration using a spectrophotometer at 634 nm using a 25 mM citrate buffer with pH 4.5 as a substrate. Findings: Maximum laccase enzyme activity in Bacillus subtilis bacteria was not significantly different at concentration of 5 mg/L of arsenic from maximum growth of bacteria in control sample and maximum growth of bacteria at concentration of 20 mg/L. However, by increasing the concentration of arsenic in the culture medium, the growth of the bacteria in the control sample, with the exception of its maximum growth in concentration of 20 mg/L, showed a significant difference with other concentrations (P

Abstract Background Renewable liquid biofuel production will reduce crude oil import of India. To displace the huge quantity of fossil fuels used for energy production, this research was focused on utilization of unexploited low-cost agricultural residues for biofuel production. Corncobs are a byproduct of corn processing industry, and till now it is not utilized for biofuel production, eventhough it has high lignocellulosic concent. In this study, combined hydrodynamic cavitation and enzymatic (HCE) method was evaluated as a pretreatment method of corncob for biofuel production. The most significant process parameters namely (i) enzyme loading (3–10 U g−1), (ii) biomass loading (2.5–5.0%), and (iii) duration (5–60 min) were optimized and their effects on combined HCE pretreatment of corncob was studied through response surface methodology for lignin reduction, hemicellulose reduction and cellulose increase. Results The highest lignin reduction (47.4%) was obtained in orifice plate 1 (OP1) under the optimized conditions namely biomass loading at 5%, enzyme loading at 6.5 U g−1 of biomass, and reaction duration of 60 min. The above tested independent variables had a significant effect on lignin reduction. The cavitational yield and energy consumption under the above-mentioned optimized conditions for OP1 was 3.56 × 10−5 g J−1 and 1.35 MJ kg−1, respectively. Conclusions It is evident from the study that HCE is an effective technology and requires less energy (1.35 MJ kg−1) than other biomass pretreatment methods.

Sixty four local isolated of Klebsiella spp. have been isolated from environment samples (soil and water). These isolates were identified and diagnosis according to phenotype and biochemical tests. These isolates were subjected to primary and secondary screening, to select the isolate with the highest laccase activity. Fifteen isolates chosen from primary screening for screening their enzyme activity in secondary screening. It has been found the Klebsiella(K7) has the highest productivity of the enzyme (12 Unit/ml).Klebsiella(K7) isolate was diagnosis by Vitak 2 system, it was identified asK. pneumonia. The laccase purified was characterization, the experiments showed that: The molecular weight of laccase was 120KD and the optimum pH for the purified laccase activity was 4.5 and for stability was 6.5. the optimum temperature for enzyme activity was 40°C, the enzyme showed that laccase lost 22, 23 and 20% of its initial activity at 20, 25 and 35°C, respectively. [ABSTRACT FROM AUTHOR]

Use of nanoparticles (NPs) in several commercial products has led to emergence of novel contaminants of air, soil and water bodies. The NPs may exhibit greater ecotoxicity due to nano-scale dependent properties over their bulk counterparts. The present investigation explores the effect of in vitro supplementation of TiO2, silica and silver NPs on radial growth and ultrastructural changes in the hyphae and spores of two mushroom genera, Ganoderma lucidum and Volvariella volvaceae. A concentration dependent decrease in radial growth on NP amended potato dextrose agar medium was recorded. However, in comparison to control, there was decrease in radial diameter on supplementation with TiO2 NPs while an increase was recorded for silica and silver NPs amendments as compared to their bulk salts at same concentrations after 48 h of incubation. Optical microscopy studies showed decrease in the number of spores while increase in spore diameter and thinning of hyphal diameter on NPs supplementation. Scanning electron microscopy analysis of fungal growth showed presence of deflated and oblong spores in two fruiting strains of Ganoderma while Volvariella exhibited decreased sporulation. Further, hyphal thinning and branching was recorded in response to NP amendments in both the test mushrooms. Enhancement of protein content was observed on NP compared to bulk supplementation for all cultures, concentrations and hours of incubation except for TiO2 NPs. Likewise, bulk and NP supplementations (at 100mg L-1) resulted in enhanced laccase activity with occurrence of laccase specific protein bands on SDS-PAGE analysis. [ABSTRACT FROM AUTHOR]

In this study, hemp fibers have been pre-treated with laccase enzyme in different concentrations (1%, 2% and 3% w/v) for different durations using conventional, ultrasonic energy and microwave energy methods. Weight loss (%), tensile strength, elongation (%), whiteness (%), and surface topography (SEM) properties of pre-treated hemp fibers were investigated. After processing with laccase enzyme, the energy consumptions of these three methods were compared. Best results have been obtained in 20 minutes with the conventional method, 5 minutes with the ultrasonic energy method, and 1 minute with the microwave energy method. With laccase enzyme, microwave treated hemp fibers were improved after 3 minutes treatment. SEM results have also proved the improved physical properties and color changes due to the rough surface structure. DOI: http://dx.doi.org/10.5755/j01.ms.23.4.17469

Graphene and its derivates offer a wide range of possibilities in the electroanalysis field, mainly owing to their biocompatibility, low-cost, and easy tuning. This work reports the development of an enzymatic biosensor using reduced graphene oxide (RGO) as a key nanomaterial for the detection of contaminants of emerging concern (CECs). RGO was obtained from the electrochemical reduction of graphene oxide (GO), an intermediate previously synthesized in the laboratory by a wet chemistry top-down approach. The extensive characterization of this material was carried out to evaluate its proper inclusion in the biosensor arrangement. The results demonstrated the presence of GO or RGO and their correct integration on the sensor surface. The detection of CECs was carried out by modifying the graphene platform with a laccase enzyme, turning the sensor into a more selective and sensitive device. Laccase was linked covalently to RGO using the remaining carboxylic groups of the reduction step and the carbodiimide reaction. After the calibration and characterization of the biosensor versus catechol, a standard laccase substrate, EDTA and benzoic acid were detected satisfactorily as inhibiting agents of the enzyme catalysis obtaining inhibition constants for EDTA and benzoic acid of 25 and 17 mmol·L−1, respectively, and a maximum inhibition percentage of the 25% for the EDTA and 60% for the benzoic acid.

Laccases are multi-copper oxidases that can act as a catalyst the oneelectron oxidation of aromatic and non-aromatic compounds which include substituted phenols, several inorganic ions, and various nonphenolic compounds with the concomitant reduction of O2 to H2O. This research aims to utilize laccase-functionalized graphene oxide (GO) as effective biodegradation of pharmaceutical industry waste: diclofenac and ibuprofen. In this study, Laccase enzyme was isolated from white oyster mushroom and immobilized with GO that was synthesized from graphite powder. Afterward, GO-laccase would be applied in degradation of diclofenac and ibuprofen. The experimental results indicated the GO-laccase had a good biodegradability to degrade pharmaceutical industry waste. Some of the compounds derived from diclofenac are N-(2,6-Dichlorophenyl) indolin-2-one, 2- (2,6-Dichloro-phenylamino)-benzaldehyde, and 2,6-Dichloroaniline, and ibuprofen is 4-Isobutylacetophenone. [ABSTRACT FROM AUTHOR]

Cooperative catalytic system of Laccase enzyme (from Trametes versicolor) and 4-phenyl urazole in phosphate buffer/acetonitrile solution at 40 °C has been applied for the biomimetic aerobic oxidative aromatization of Hantzsch 1,4-dihydropyridines (1,4-DHPs) with excellent yields. [ABSTRACT FROM AUTHOR]

The aim of this article was to clarify which type of dye chromophores could be decolorized efficiently with the use of laccase enzyme. For this purpose, enzymatic degradation of different type of dye classes (4 reactive, 2 acid and 1 basic dye) having various chromophore groups was investigated by using commercial laccase from Cerrena unicolor. It was observed that the chromophore structure of dye is very important on enzymatic color removal efficiency. According to the experimental results, it was found that color removal efficiencies (20 mg/L initial dye) were 98.7% for RB220 (0.1 g/L enzyme after 6 h), 95.1% for RB19 (0.1 g/L enzyme after 48 h), 90.8% for AR42 (0.1 g/L enzyme after 48 h) while they were 60.9% for AR114 (0.25 g/L enzyme), 58.6% for RB21 (0.5 g/L enzyme), 39.7% for RR239 (0.25 g/L enzyme) even after seven days. As a result, it can be said that the highest decolorization rate was achieved for the reactive dye having formazan copper complex (RB220) chromophore. On the other hand, the enzymatic degradation of basic dye (BB9) was found to be rather difficult compared to the acid and reactive dyes used in this study and the maximum color removal was 42.8% after seven days. [ABSTRACT FROM AUTHOR]

Laccase enzyme was used as a pretreatment agent to delignify empty fruit bunches (EFB) for sugar production. The degree of delignification of the biomass was assessed directly by the percentage of pre-pretreatment weight loss (%) after pretreatment and indirectly by the amount of total sugar produced after saccharification of the pretreated biomass with cellulase enzymes. Process parameters such as pretreatment time, temperature, enzyme concentration, substrate concentration, pH, and substrate size were studied using a one-factor-at-a-time (OFAT) analysis. The combined effect of temperature and pH on the pretreatment was studied using the face-centered central composite design (FCCCD) of response surface methodology (RSM). The optimized conditions for EFB pretreatment using laccase enzyme were achieved as follows: sample size, 2 mm; temperature, 25 °C; time, 4 h; substrate concentration, 5% (w/v); pH 5; and enzyme concentration, 20 IU/g of EFB. Although higher pretreatment was achieved with substrates of 1 mm size and at a temperature of 35 °C, these conditions were not considered energetically sustainable because of the need for energy during milling for sample size reduction and energy for temperature maintenance at 35 °C.

The saccharification of laccase-pretreated empty fruit bunch (EFB) was optimized in a lab-scale experiment using one-factor-at-a-time (OFAT) and response surface methodology (RSM). After pretreatment, the degree of delignification was checked by noting the weight loss (%) after pretreatment, and also by the quantity of total sugar produced after saccharification with cellulase enzyme. OFAT studies of saccharification of the pretreated EFB showed that the biomass was best saccharified using cellulase enzyme at the following conditions: enzyme concentration of 30 IU/g of EFB, substrate concentration of 5.0% w/v, 50 °C, saccharification time of 24 h, and pH 5. This combination exhibited the highest yield of total sugar (28% w/w). Although 29% w/w yield was achieved with an enzyme concentration of 40 IU/g of EFB, this increase in yield was not proportional to the increased enzyme concentration and, therefore, was considered insignificant. Statistical analysis of the combined effects of pH and temperature showed that pH had a more significant effect than the temperature on the saccharification process, based on a P < 0.05 significance level. The effect of pH on total sugar production was more significant than the temperature in both linear and quadratic functions. In sum, the saccharification of laccase-pretreated EFB should follow the optimized process conditions achieved in the current study.

Background and Objectives: Laccase is the most abundant member of protein family that catalyzes the oxidation of substituted phenols. Laccases are used as biocatalysts for decolorization and bleaching in dye industries, detoxification in environment, and juice clarification in food industries. The present study aimed at producing recombinant laccase, purifying with high yield and fold, and characterizing biochemical and kinetic properties of the purified laccase. Materials and Methods: In this laboratory study, recombinant Trametes laccase, which was successfully expressed in yeast host in extracellular form, was purified through ultrafiltration and gel chromatography methods. The purification process yield and fold was determined and after molecular weight determination, physiochemical properties of recombinant laccase were studied and its thermostability was determined. All tests were conducted with at least 3 times repetition and mean and standard deviation calculation. Results: Purification strategy showed that laccase was successfully purified with 5.67 fold and 49.7% yield and the molecular weight of recombinant laccase was determined 65KDa. Optimum pH and temperature of the recombinant laccase were determined 4.8 and 60°C, respectively. Its kinetic properties were also determined. The thermostability assessment showed that purified laccase is highly thermostable. Conclusion: The results indicated that gel chromatography purification method can be an ideal to achieve high yield and fold purification of recombinant laccase with keeping enzyme properties and high thermostability, so that the recombinant purified laccase with high yield and fold can be used in drug, textile, and food industries, and environment and its detoxification. [ABSTRACT FROM AUTHOR]

In this study (34) samples of fungal from infected fruits and vegetables were isolated related to the following species:Alternariaalternata,Aspergillusflavus,A. niger,Fusarium sp. and Penicillium sp. Their ability to produce Laccase enzyme was studied and the study showed the ability of (11) fungal isolates to produce this enzyme and the A. alternata is the strongest one to produce the Laccase enzyme reaching (1.35 U/ml). Optimization of some nutritional and physical factors in the basal medium in order to intensify the production from A. alternata. The optimization studies revealed that the maximum Laccase production was achieved when the production medium was at the following conditions: pH 5.5 sucrose as a carbon source, yeast extract as nitrogen source was (4.01 u/ ml). [ABSTRACT FROM AUTHOR]

The first report on aerobic in situ generation and regeneration of N -phenyltriazolinedione, a valuable oxidizing agent, from a catalytic amount of N -phenyl urazole in the presence of a laccase enzyme is presented. The application of a 4-phenyl urazole/Laccase/O 2 as a new cooperative catalytic oxidation system is reported for a transition-metal-free and halogen free oxidative homo-coupling reaction of structurally diverse thiols to their corresponding disulfides with good to excellent yields in a phosphate buffer solution under mild reaction conditions. [ABSTRACT FROM AUTHOR]

Six different bacterial and fungal isolates included Pseudomonas sp., Bacillus sp., Candida sp., Klaveromyces sp., Aspergillus sp. and Streptomyces sp. were tested to produce laccase enzyme by using submerged fermentation, Streptomyces sp., Candida sp., and Pseudomonas sp. were chosen as being the heaviest in terms of enzyme production, and were tested for laccase production by solid state fermentation using different supports such as a solid media including sawdust with 0.06% xylene, sawdust and bran mixture (2:1) with 0.06% xylene. By using a combination of sawdust and bran (2:1), the productivity of laccase produced from Streptomyces sp., Candida and Pseudomonas sp. reached 177.8, 144.3 and 103.46 U. g-1 respectively. Streptomyces sp., isolate was chosen for laccase production. Optimum conditions for laccase production was determined from the selected isolate Streptomyces sp. by using an amalgamation of sawdust and bran (2:1) in pH 5.5 and the medium was incubated at 30oC for 14 days. This specific activity for laccase enzyme reached 1315 U.mg-1. The maximum removal efficiency of textile dyes such as (yellow, red and black) by crude laccase was reached 87%, 43% and 74% respectively after a period of 3 hours. [ABSTRACT FROM AUTHOR]

Extracellular laccase produced from a novel soil bacterium Brevibacterium halotolerans N11 (KY883983) was purified with molecular weight of 55 kDa. Different carriers such as Ca-alginate, agarose-agar, agar-agar, alginate-gelatin mixed gel and polyacrylamide gel were utilized for laccase immobilization through this study. Kinetic properties of immobilized laccase showed that, K m value was slightly increased while V max was decreased compared to free counterpart. The optimum pH and temperature values were increased from 5 and 35 °C to 6 and 40 °C of free and immobilized laccases, respectively. Also, the thermal stability of immobilized laccase is more than the free one with Tm values of 58 °C and 26 °C, respectively. The immobilized laccase could be reused for seven continuous cycles with retained 65% of its initial activity. Thus, the immobilization process improved the enzyme thermal stability, reusability and reduced the enzyme cost. Due to synthetic dyes released to the environments and their low biodegradability, this study focused on the potential role of free and immobilized laccases as agents for biodegradation of synthetic dyes, especially: azo, triarylmethane and anthraquinone dyes under different conditions. Therefore, the biodegradation of different synthetic dyes by free and immobilized laccases was also studied. Both the free and the immobilized laccases exhibited high decolorization efficiency to congo red dye (50 mg L −1 ) at 40 °C for free enzyme and 50 °C for immobilized laccase after 24 h and pH 5.5. Our results confirm the role of B. halotolerans N11 laccase in dye decolorization and wastewater detoxification. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the potential of crude oil removal by fungal strains isolated from Arak refinery. The results showed that the RH10 strain is a potent strain as a surfactant producer and degrader of petrochemical hydrocarbons. The strain was identified as a Fusarium neocosmosporiellum and could degrade 58% of hydrocarbons in the minimal medium and reduce the surface tension from 45 to 26.5 mN m−1. Moreover, residual crude oil analysis with Fourier transform infrared spectrophotometry showed that this strain was able to degrade 50% of aliphatic compounds. To investigate the mechanism of degradation, oxidase enzymes were assayed and it was found that F. neocosmosporiellum can produce 1.94 U L−1 of laccase in 10 g L−1 crude oil. Carbon, nitrogen, phosphorus and soil pattern optimization in a microcosm study showed that this strain removed 44% and 27% of the crude oil from contaminated soil in 1% and 5% crude oil concentrations, respectively. Under optimum condition, 9.66 g kg−1 crude oil was removed by F. neocosmosporiellum when the initial oil concentration was 50 g kg−1, at the end of 150 days microcosm experiment. The results demonstrated the promising potential of fungi strain for cleaning of contaminated soil. [ABSTRACT FROM AUTHOR]

A novel carbon-fiber-brush air cathode microbial fuel cell (MFC) with low-cost mushroom Ganoderma laccase enzyme was used to treat molasses wastewater. Experimental results indicate that the laccase activity of Ganoderma lucidum was considerably greater than Pleurotus eryngii and Simplicillium obclavatum . The maximal laccase activity (108 U/L) was reached in the presence of 125 µM of CuSO 4 on day eight. Adding the laccase broth to the cathode clearly enhanced the MFC performance. The MFC with crude laccase broth generated more electricity (420 mV) than with filtered broth (300 mV). Increasing the liquid level of the cathode and increasing the sets of cathodes increased the generation of electricity. Under optimal operational conditions, a power density of 40 mW cm 2 was achieved and the MFC effectively maintained the power generation as long as 45 days. DGGE profile and dendrogram analysis were also used to investigate the microbial community structure in the anode chamber. [ABSTRACT FROM AUTHOR]

Azo dyes are a common pollutant in industrial wastewater, especially in textile industries. Due to their indigenous toxicity and environmental and water resources hazards, public concerns are increasingly growing to find a suitable solution. In recent years, enzyme-based processes, particularly the use of laccase enzymes for wastewater treatment, have received broad awareness due to their performance and sustainability. This study investigated the activity, crude enzyme production and decolorization performance of the laccase enzyme from Megasporoporia sp. in solid-state media. The production of the enzyme in solid-state media was executed in two coupled modes of biphenyl as inducer and without biphenyl. The results showed a 62% increase in biphenyl enzyme production in the culture medium. Then the produced enzyme was used for decolorization examination for four different azo dyes. Enzyme activity and optimized dye removal performance were investigated for each dye at a different temperature, pH and times. Laccase enzyme from Megasporoporia sp. provides valuable insights into the potential use of these enzymes from an unstudied biological source for sustainable treatment of industrial wastewater contaminated with azo dyes. By understanding production parameters and optimizing enzyme performance conditions, this research can contribute to developing enzyme-based processes that offer a suitable solution to mitigate the environmental and water resource hazards associated with azo-dye pollution in different industries. • The laccase showed high efficiency in the Azo dyes removal. • Solid-state fermentation provided high laccase production using Megasporoporia sp. • Biphenyl as an inducer showed a high-efficiency rate of laccase production. • The greatest decolorization effect of laccase was displayed on the malachite green. [ABSTRACT FROM AUTHOR]

The direct aerobic oxidation of 4-substituted urazoles using the laccase enzyme from Trametes versicolor in a phosphate buffer solution at ambient temperature, and subsequent cross-coupling with sodium benzenesulfinates was investigated to afford arylsulfonyl-1,2,4-triazolidine-3,5-dione derivatives in good to high yields. [ABSTRACT FROM AUTHOR]

White-rot fungi are considered to be promising biotechnological tools to complement or replace the current technologies for the treatment of effluents from textile production plants. The aim of this work was to investigate the decolorization capacity of Ganoderma weberianum B-18 in solid state fermentation with sugarcane bagasse as a substrate and ligninolytic inducer as well as to decolorize and detoxify industrial effluents by this strain in a laboratory scale packed-bed bio-reactor. The results demonstrated that G. weberianum B-18 indeed showed to possess decolorization capacity in solid state fermentation with sugarcane bagasse supplemented with synthetic dyes. Moreover, fungal biomass of G. weberianum B-18 immobilized in sugarcane bagasse in a packed-bed bioreactor was shown to efficiently decolorize and detoxify different dyes and authentic industrial effluents in semi-continuous conditions. In this decolorization process, laccase enzymes secreted by the fungus played the main role. Hence, a packed-bed reactor with G. weberianum B-18 immobilized in sugarcane bagasse seems to be a suitable system for the further development of an efficient bioprocess for large-scale treatment of dye-containing wastewaters. [ABSTRACT FROM AUTHOR]

This research investigates the effects of titanium dioxide (TiO2) on the laccase enzyme immobilization and the BPA removal performance of the ceramic membranes. There were four types of experimental ceramic membranes: the ceramic membrane, TiO2-coated membrane, laccase-immobilized membrane, and laccase-immobilized TiO2-coated membrane. The laccase concentrations were varied between 0, 500, 2500 and 5000 U L–1. The experimental results revealed that TiO2 improved the laccase immobilization as TiO2 increased the membrane surface area, formed the mesoporous structure and induced the stronger binding between the membrane surface and the enzyme. Moreover, the laccase-immobilized TiO2-coated membrane with 5000 U L–1 laccase concentration achieved the highest BPA removal efficiency of 93%. The TiO2-coated membrane could achieve a higher BPA removal efficiency (31%) than the ceramic membrane (9%) and the 500 U L–1 laccase-immobilized membrane (20%). The finding was attributable to the improved degradation of organic pollutants as a result of higher photocatalytic performance under visible light and the enhanced organic-pollutants adsorption capacity of the TiO2-coated membrane. [ABSTRACT FROM AUTHOR]

In this study, hemp fibers have been pre-treated with laccase enzyme in different concentrations (1%, 2% and 3% w/v) for different durations using conventional, ultrasonic energy and microwave energy methods. Weight loss (%), tensile strength, elongation (%), whiteness (%), and surface topography (SEM) properties of pre-treated hemp fibers were investigated. After processing with laccase enzyme, the energy consumptions of these three methods were compared. Best results have been obtained in 20 minutes with the conventional method, 5 minutes with the ultrasonic energy method, and 1 minute with the microwave energy method. With laccase enzyme, microwave treated hemp fibers were improved after 3 minutes treatment. SEM results have also proved the improved physical properties and color changes due to the rough surface structure. [ABSTRACT FROM AUTHOR]