Crude Laccase Research Articles

Enhancing Laccase Production by Trametes hirsuta GMA-01 Using Response Surface Methodology and Orange Waste: A Novel Breakthrough in Sugarcane Bagasse Saccharification and Synthetic Dye Decolorization

Trametes hirsuta GMA-01 was cultivated in a culture medium supplemented with orange waste, starch, wheat bran, yeast extract, and salts. The fungus produced several holoenzymes, but the laccase levels were surprisingly high. Given the highlighted applicability of laccases in various biotechnological areas with minimal environmental impact, we provided a strategy to increase its production using response surface methodology. The immobilization of laccase into ionic supports (CM-cellulose, DEAE-agarose, DEAE-cellulose, DEAE-Sephacel, MANAE-agarose, MANAE-cellulose, and PEI-agarose) was found to be efficient and recuperative, showcasing the technical prowess of research. The crude extract laccase (CE) and CM-cellulose-immobilized crude extract (ICE) showed optimum activity in acidic conditions (pH 3.0) and at 70 °C for the CE and 60 °C for the ICE. The ICE significantly increased thermostability at 60 °C for the crude extract, which retained 21.6% residual activity after 240 min. The CE and ICE were successfully applied to sugarcane bagasse hydrolysis, showing 13.83 ± 0.02 µmol mL−1 reducing sugars after 48 h. Furthermore, the CE was tested for dye decolorization, achieving 96.6%, 71.9%, and 70.8% decolorization for bromocresol green, bromophenol blue, and orcein, respectively (0.05% (w/v) concentration). The properties and versatility of T. hirsuta GMA-01 laccase in different biotechnological purposes are interesting and notable, opening several potential applications and providing valuable insights into the future of biotechnological development.

Short Communication: Candida sp. isolated from mangrove soils for biological decolorization of textile reactive dyes

Abstract. Boontanom P, Chantarasiri A. 2024. Short communication: Candida sp. isolated from mangrove soils for biological decolorization of textile reactive dyes. Biodiversitas 25: 2595-2602. Effluent discharge from dye-related industries is a significant environmental pollution problem and a concern for human health. Dyes have harmful effects on aquatic organisms due to their toxic properties. One possible solution is using microorganisms for the biological decolorization of textile reactive dyes as an eco-friendly and potentially lucrative alternative to physicochemical processes. Therefore, this study isolated an effective dye-decolorizing yeast from mangrove soil samples in Thailand and investigated the decolorization efficiency of eight textile reactive dyes under experimental conditions. Yeasts have several advantages over other bacteria and fungi for the biological decolorization of textile reactive dyes, but the number of dye-decolorizing yeasts discovered in mangrove soils remains scarce. The most effective dye-decolorizing yeast, isolate RY21703, showed Remazol Brilliant Blue R (RBBR) decolorization of 37.50±0.07% within 72 h of incubation. This yeast isolate was genetically and phylogenetically identified as Candida sp. strain RY21703 and produced 0.97±0.08 U/mL of crude laccase activity, an essential enzyme in dye decolorization mechanisms. Candida sp. strain RY21703 showed strong decolorization efficiency after 72 h of incubation in all azo-reactive dyes, ranging from 27.32±3.34% (CI Reactive Orange 122) to 61.45±1.43% (CI Reactive Green 19). This strain also decolorized phthalocyanine reactive dye (CI Reactive Blue 21) by 60.71%. Findings suggested that this mangrove yeast can be used for the biological decolorization of dyeing wastewater.

Valorization of sugarcane bagasse for high-yield production of laccase through Aspergillus terreus for effective azo dye decolourization

Synthetic dyes such as azo dyes are significant pollutants in the wastewater released from various textile industries. The low biodegradability and production from synthetic sources with high shelf life make azo dyes a challenging material for degradation. This study used chemically mutated Aspergillus terrus in the laccase production under solid-state fermentation using sugarcane bagasse. Initially, the wild-type strain produced a laccase activity of 4.12 U/mL. Later, the alkaline pretreatment of sugarcane bagasse showed a significant increase in laccase activity by 38.9%. Further, random mutagenesis treatment with 100 mM EMS generated a hyper laccase-producing strain with a 2.3-fold increment in laccase activity compared to the wild-type strain. The enzyme displayed optimal activity at pH 6.5 and 35 °C. The metal ions such as Fe3+ (29.4 U/mL), Fe2+ (20.8 U/mL) and Cu2+ (18.05 U/mL) showed positive effects on laccase activity. The crude laccase was used to bioremediate Congo red, a prominent azo dye used in textile and pharmaceutical industries. The preliminary studies with a crude enzyme displayed 68.86% dye decolourization after 24 h of incubation. Additionally, with Taguchi orthogonal array optimization experiments, the maximal dye decolorization of 78.24% was achieved by maintaining crude enzyme concentration (20 U), dye concentration (25 mg/L) and pH 4.5.

Purification, kinetic characterization of thermostable multicopper oxidase from the oyster mushroom and its versatility for greener agro-pulp bio bleaching in the paper industry.

Production of a thermostable laccase from Pleurotus florida was reported for the first time, both in submerged and solid-state fermentation using agro-industrial residues. This enzyme was purified using ammonium sulphate precipitation (60-90%), Sephadex G-100 and DEAE column ion exchange chromatography, respectively. The laccase was purified to 21.49 fold with an apparent molecular weight of 66 kDa and had an optimal pH of 5 with temperature stability at 60°C. Metal ions such as Cu2+ (91.26 µmole/mL/min), Mg2+ (68.15 µmole/mL/min), and Fe2+ (1.73 µmole/mL/min) enhanced the laccase activity, but Fe2+ (1.73µmole/mL/min) inhibited the enzyme activity. The purified laccase had Km and Vmax of 16.68 mM and 26.73 µmole/mL/min for guaiacol as a substrate. The isolated enzyme was characterized by FT-IR which revealed bands at 3655.0 cm-1, 2894.7 cm-1, and 1151.7 cm-1 corresponding to primary amines, C-H stretch, and amide -III, respectively. The enzymatic bio bleaching of paddy straw pulp was found to be most effective which resulted in a lowering of kappa number and yellowness by 19.47% & 17.84% whereas an increase in brightness and whiteness by 41.92%. & -19.61%. Thus, this might be stated that the crude laccase from P. florida can be exploited to reduce the toxic waste load for managing environmental pollution and helps in enhancing the yield and quality of the paper.

BIODELIGNIFICATION OF AGRO-INDUSTRIAL WASTE AS THE SUBSTRATE TO PRODUCE LACCASE ENZYME FROM TRAMETES VERSICOLOR

Agro-industrial waste in Indonesia is a significant problem for the environment. Optimization of agro-industrial waste utilization is an exciting thing to be researched further. This study aims to utilize agro-industrial waste to optimize laccase enzyme production. The agro-industrial waste used is in the form of bagasse, rice straw, and corn stalks. The waste is used as biomass and treated to extract cellulose through bio-delignification. Cellulose serves as a substrate substance in the production of laccase enzymes. Laccase enzymes can be applied as a biocatalyst in the environmental, pharmaceutical, and chemical industries. Cellulose from agroindustry waste was synthesized by heat treatment using steam explosion with the operation conditions 200°C and 10 bar for 10 minutes. The production of laccase enzymes was done using the green technology submerged fermentation method for 32 hours at 25°C. The optimal result in producing laccase enzyme is using substrate from corn stalks and adding nutrients with an activity value of 25.46 U/mL. The reaction kinetics of laccase enzyme and commercial enzyme against 0.1 M substrate were modelled using the Euler method, and the k value was 2x10-4 min-1 (crude laccase) and 1.9x10-2 min-1 (commercial laccase).

Effective Decolorization and Detoxification of Single and Mixed Dyes with Crude Laccase Preparation from a White-Rot Fungus Strain Pleurotus eryngii.

To fully harness the potential of laccase in the efficient decolorization and detoxification of single and mixed dyes with diverse chemical structures, we carried out a systematic study on the decolorization and detoxification of single and mixed dyes using a crude laccase preparation obtained from a white-rot fungus strain, Pleurotus eryngii. The crude laccase preparation showed efficient decolorization of azo, anthraquinone, triphenylmethane, and indigo dyes, and the reaction rate constants followed the order Remazol Brilliant Blue R > Bromophenol blue > Indigo carmine > New Coccine > Reactive Blue 4 > Reactive Black 5 > Acid Orange 7 > Methyl green. This laccase preparation exhibited notable tolerance to SO42- salts such as MnSO4, MgSO4, ZnSO4, Na2SO4, K2SO4, and CdSO4 during the decolorization of various types of dyes, but was significantly inhibited by Cl- salts. Additionally, this laccase preparation demonstrated strong tolerance to some organic solvents such as glycerol, ethylene glycol, propanediol, and butanediol. The crude laccase preparation demonstrated the efficient decolorization of dye mixtures, including azo + azo, azo + anthraquinone, azo + triphenylmethane, anthraquinone + indigo, anthraquinone + triphenylmethane, and indigo + triphenylmethane dyes. The decolorization kinetics of mixed dyes provided preliminary insight into the interactions between dyes in the decolorization process of mixed dyes, and the underlying reasons and mechanisms were discussed. Importantly, the crude laccase from Pleurotus eryngii showed efficient repeated-batch decolorization of single-, two-, and four-dye mixtures. This crude laccase demonstrated high stability and reusability in repeated-batch decolorization. Furthermore, this crude laccase was efficient in the detoxification of different types of single dyes and mixed dyes containing different types of dyes, and the phytotoxicity of decolorized dyes (single and mixed dyes) was significantly reduced. The crude laccase efficiently eliminated phytotoxicity associated with single and mixed dyes. Consequently, the crude laccase from Pleurotus eryngii offers significant potential for practical applications in the efficient decolorization and management of single and mixed dye pollutants with different chemical structures.

Biochemical Characterization of Laccase from Spirulina CPCC-695 and Their Role in Estrone Degradation.

The addition of exogenous endocrine disrupting compounds (EDCs) like estrone, in the food chain through the aquatic system, disrupts steroid biosynthesis and metabolism by altering either the genomic or non-genomic pathway that eventually results in various diseases. Thus, bioremediation of these compounds is urgently required to prevent their addition and persistence in the environment. Enzymatic degradation has proven to be a knight in shining armour as it is safe and generates no toxic products. The multicopper oxidases (E.C. 1.10.3.2 benzenediol: oxygen oxidoreductase), laccase with the potential to degrade both phenolic and non-phenolic substrates has recently gained attention. In this study, the laccase was purified, characterized, and used to study estrone degradation. The culture filtrate (crude laccase) was concentrated and precipitated using cold-acetone and dialyzed against tris buffer (50mM) giving a four-fold partially purified form, with 45.56% yield and 204.14 U/mg as specific activity and a single peak at 250-300nm. The partially purified laccase was approximately 80kDa as estimated by SDS-PAGE preferred ABTS as substrate. Both crude and partially purified laccase showed maximum activity at pH 3.0, 40°C, and 4mM ABTS. Kinetic constants (Km, Vmax) of crude and partially purified laccase were found to be 0.83mM; 494.31mM/min, and 0.58mM; 480.54mM/min respectively. Iron sulphate and sodium azide inhibited laccase maximally. Crude and partially purified laccase degradation efficiency was 87.55 and 91.35% respectively. Spirulina CPCC-695 laccase with efficient estrone degradation ability renders them promising candidates for EDCs bioremediation.

The enzymatic decolorization of leather azo dyes (AB 113 and AB 52) using crude fungal laccase: an eco-friendly approach towards pollution reduction

The enzymatic decolorization of leather azo dyes (AB 113 and AB 52) using crude fungal laccase: an eco-friendly approach towards pollution reduction

Systematic characterisation, and effect of nutritional and physical parameters on culturability, laccase production and dye decolorisation potential by P. pistillaris from Pakistan

Podaxis pistillaris is neutraceutically, cosmoceutically and medicinally recognised macrofungus. During this research work, this edible mushroom was systematically characterised. Its culturability, laccase production, and dye decolorisation potential were evaluated and optimised. Among the different media tested, PDA proved as most efficient medium for culturability of P. pistillaris. Conditions for laccase production were optimised in submerged state fermentation. Maximum laccase secretion was noted after 14th day of Incubation at 35 °C with 130 rpm and 5 pH of medium. Fructose and ammonium-phosphate was found as best carbon and nitrogen source, while wheat straw revealed as good ligno-cellulosic source for strengthening laccase production. Congo-red dye decolorisation capability by crude laccase enzyme was evaluated and found maximum decolorisation potential (92.2%) after 288h of incubation. From this pilot study, it was confirmed that this edible macrofungus has culturability, laccase production and dye decolorisation attributes that will further contribute in delignification, biosorption and bioremediation.

Deciphering ligninolytic enzymes in the secretome of Pycnoporus sp. and their potential in degradation of 2-chlorophenol.

Chlorophenols and their derivatives are persistent environmental pollutants, posing a threat to terrestrial and aquatic life. The biological approach for eliminating toxic contaminants is an effective, sustainable, and environmental friendly method. In this study, the crude enzymes present in the secretome of white-rot fungus (Pycnoporus sp.) were explored for the degradation of 2-chlorophenol. The activity of ligninolytic enzymes in the secretome was analyzed and characterized for their kinetics and thermodynamic properties. Laccase and manganese peroxidase were prevalent ligninolytic enzymes and exhibited temperature stability in the range of 50-65°C and pH 4-5, respectively. The kinetic parameters Michaelis constant (Km) and turnover number (Kcat) for Lac were 42.54μM and 45s-1 for 2,2'-azino-bis (3-ethylben- zothiazoline-6-sulfonic acid), and 93.56μM and 48s-1 towards 2,6-dimethoxyphenol whereas Km and Kcat for MnP were 2039μM and 294s-1 for guaiacol as substrate. Treatment with the crude enzymes laccase and manganese peroxidase results in the reduction of 2-chlorophenol concentration, confirmed by UV-visible absorption spectra and high-performance liquid chromatography analysis. The detoxification of 2-chlorophenol into less toxic forms was confirmed by the plate toxicity assay. This study demonstrated that crude enzymes produced by Pycnoporus sp. could potentially minimize the toxicity of phenolic compounds in a sustainable way.

Improved laccase production by Trametes versicolor using Copper-Glycyl-L-Histidyl-L-Lysine as a novel and high-efficient inducer.

A highly efficient strategy using Copper-Glycyl-L-Histidyl-L-Lysine (GHK-Cu) as a novel inducer was developed to enhance laccase production by Trametes versicolor. After medium optimization, laccase activity increased by 12.77-fold compared to that without GHK-Cu. The laccase production of 1113.8U L-1 was obtained by scaling-up culture in 5-L stirring tank. The laccase production induced by CuSO4 was poorer than that of GHK-Cu at the same mole concentration. GHK-Cu could increase the permeability of cell membrane with less damage, and it facilitated the adsorption, accumulation, and utilization of copper by fungal cells, which was beneficial for laccase synthesis. GHK-Cu induced better expression of laccase related genes than that of CuSO4, resulting in higher laccase production. This study provided a useful method for induced production of laccase by applying GHK chelated metal ion as a non-toxic inducer, which reduced the safety risk of laccase broth and provided the potential application of crude laccase in food industry. In addition, GHK can be used as the carrier of different metal ions to enhance the production of other metalloenzymes.

Optimization of laccase enzyme extraction from spent mushroom waste of Pleurotus florida through ANN-PSO modeling: An ecofriendly and economical approach

The cardinal focus of this study is to optimize the best reaction conditions for maximizing laccase activity from spent mushroom waste (SMW) of Pleurotus florida. Optimization process parameters were studied by the modeling techniques, artificial neural networking (ANN) embedded in particle swarm optimization (PSO), and response surface model (RSM). The best topology of ANN-PSO architecture was obtained on 4-10-1. The R2, IOA, MSE, and MAE values of the ANN model were obtained as 0.98785, 0.9939, 0.0023, and 0.0251 while, that of the RSM model were obtained as 0.74290, 0.9210, 0.0244, and 0.1110 respectively. The higher values of R2, IOA, and lower values of MSE and MAE of the ANN-PSO model depict that ANN-PSO outperformed compared to RSM and also verified the effectiveness of the ANN-PSO model. The ANN-PSO model performance demonstrates the robustness of the technique in optimizing laccase activity in SMW of P. florida. The optimization results revealed that pH 4.5, time 3 h, solid: solution ratio 1:5, and ABTS concentration of 1 mM was optimal for achieving maximum laccase activity at temperature 30 °C. The enzymatic activity of crude laccase enzyme was obtained as 1.185 U ml−1 without loss of enzyme activity. Additionally, crude laccase enzyme was 1.74 fold partially purified, and 83.54% of the enzyme was yielded. Out of all the independent process variables, ABTS and pH had an influence on laccase activity. Therefore, we anticipate that the findings of this investigation will reduce the ambiguity in maximizing laccase activity and ease the screening process. This study also highlights the comparative cost evaluation of crude laccase enzyme extracted from P. florida and commercial enzymes. There is a great potential for the utilization of the laccase enzyme extracted from SMW and using it for the degradation of recalcitrant micropollutants. Thus, SMW promises a cost-effective and sustainable approach leading towards circular economy.

Biotransformation of bisphenol A in vivo and in vitro by laccase-producing Trametes hirsuta La-7: Kinetics, products, and mechanisms

Bisphenol A (BPA) is a ubiquitous endocrine disruptor that poses adverse human health risks. Herein, biotransformation kinetics, products, and mechanisms of BPA undergoing a laccase-producing Trametes hirsuta La-7 metabolism were for the first time reported. Strain La-7 could completely biotransform ≤0.5 mmol·L−1 BPA within 6 d in vivo. Notably, its extracellular crude laccase solution (ECLS) and intracellular homogenized mycelium (HM) only required 6 h to convert 85.71% and 84.24% of 0.5 mmol·L−1 BPA in vitro, respectively. The removal of BPA was noticeably hampered by adding a cytochrome P-450 inhibitor (piperonyl butoxide) in HM, disclosing that cytochrome P-450 monooxygenase participated in BPA oxidation and metabolism. BPA intermediates were elaborately identified by high-resolution mass spectrometry (HRMS) combined with 13C stable isotope ratios (BPA: 13C12-BPA = 0.25: 0.25, molar concentration). Based on the accurate molecular mass, isotope labeling difference, and relative intensity ratio of product peaks, 6 versatile metabolic mechanisms of BPA, including polymerization, hydroxylation, dehydration, bond cleavage, dehydrogenation, and carboxylation in vivo and in vitro, were confirmed. Germination index values revealed that inoculating strain La-7 in a BPA-contaminated medium presented no phytotoxicity to the germinated radish (Raphanus sativus L.) seeds. In vivo, Mg2+, Fe2+, Fe3+, and Mn2+ were conducive to BPA removal, but Cd2+ and Hg2+ significantly obstructed BPA elimination. Additionally, strain La-7 also exhibited high-efficiency metabolic ability toward estrone (E1), 17β-estradiol (E2), and 17α-ethinylestradiol (EE2), with more than 96.13%, 96.65%, and 100% of E1, E2, and EE2 having been converted, respectively. Our findings provide an environmentally powerful laccase-producing fungus to decontaminate endocrine disruptor-contaminated water matrices by radical polymerization and oxidative decomposition.

Evaluation of Dye Decolourization ability of Laccase Produced Curvularia lunata SS17

The increasing discharge of dyes into the environment and their consequential ecological effects has necessitated the need for the ecofriendly decolourization methods. Laccases became enzymes of research interest due to their broad substrates specificities. The aim of the study was to purify, characterize and determine the decolourization ability of Curvularia lunata SS17 produced laccase. Laccase was produced using maize cob as substrate under optimized culture conditions and purified using Gel Filtration Chromatography. Biuret method was then used to estimate the protein contents of the crude and partially purified laccase. Specific activities, purification fold and yield (%) of the crude and purified laccase enzyme were also estimated. Decolourization potentials of the crude and partially purified enzyme were evaluated using four dyes namely: Congo red, Methylene blue, Bromocresol green and direct yellow. Elution profile of partially purified laccase revealed that fraction 5 had the highest laccase activity (3.654 U/mL). Optimum conditions for enzyme activity were estimated to be 35oC and pH 6. Enzyme activity of the partially purified laccase (3.654 U/mL) was observed to be higher than that of the crude laccase (1.635 U/mL). Also, the partially purified laccase had higher specific activity (1.87 U/mg) compared to that of the crude laccase (0.41 U/mg). Higher percentage dye decolourization potential was observed using the partially purified laccase compared to the crude laccase. Increase in percentage decolourization of the dyes by the partially purified laccase as well as crude laccase was observed as incubation time proceeds.

Purification and Characterization Laccase from Trametes versicolor (L.) Lloyd in Submerged Fermentation.

<b>Background and Objective:</b> Laccase is classified as an oxidoreductase enzyme that catalyzes oxidation reactions of phenolic groups by using oxygen as its electron acceptor. Laccase isolated from <i>Trametes versicolor</i> (L.) Lloyd has a wide range of applications in the industrial sector. The use of enzymes in the industrial sector requires pure enzyme conditions from impurities so that the enzyme can maximize its ability in converting the substrate. This study aims to obtain enzyme activity and the characteristic of purified laccase enzymes isolated from <i>Trametes versicolor</i> (L.) Lloyd. <b>Materials and Methods:</b> This study was conducted with an experimental method followed by descriptive analysis. The steps of this research consist of a qualitative assay of laccase enzyme, crude laccase extract desalting by Sephadex G-25, laccase purification by Sephadex G-100 and laccase optimum pH characterization. <b>Results:</b> The result of this study showed that purification of laccase from <i>Trametes versicolor </i>(L.) Lloyd with Sephadex G-25 increases laccase enzyme-specific activity which is 10.966 U mg<sup>1</sup> and reaches 2.93-fold purity. The highest laccase enzyme activity was achieved at pH 4 with a value of laccase activity 62.39 U L<sup>1</sup>. <b>Conclusion:</b> Based on current results, purifying laccase from <i>Trametes versicolor </i>(L.) Lloyd with Sephadex G-25 was recommended which resulting higher enzyme specific activity.

Tailor-made novel electrospun polycaprolactone/polyethyleneimine fiber membranes for laccase immobilization: An all-in-one material to biodegrade textile dyes and phenolic compounds

In spite of many works on the biodegradation of textile dyes and phenolic compounds, we propose a new, inexpensive, environmentally friendly, and sustainable material based on electrospun fiber and immobilized laccase. The polycaprolactone (PCL)/polyethyleneimine (PEI) electrospun fibers were optimized and prepared by electrospinning technique according to the operational parameters like PCL concentration (12 wt%), PEI concentration (10 wt%), voltage (16 kV), needle tip-collector distance (20 cm), and injection speed (0.7 mL/h). Next, characterization studies were performed to investigate the morphology and structure of the electrospun fibers without and with laccase. The crude laccase was obtained by cultivating the white rot fungus T. trogii (TT), and T. versicolor (TV). The resulting electrospun fibers showed a smooth surface with a mean diameter of around 560 nm, and larger diameters were observed after laccase immobilization. According to the results, immobilization increased the stability properties of laccase such as storage, and operational. For instance, the residual activity of the PCL/PEI/TTL and PCL/PEI/TVL after 10 repeated cycles, was 33.2 ± 0.2% and 26.0 ± 0.9%, respectively. After 3 weeks of storage, they retained around 30% of their original activity. Moreover, the PCL/PEI/TTL and PCL/PEI/TVL were found to possess high decolorization yield to remove Orange II and Malachite Green textile dyes from solutions imitating polluted waters. Among them, the PCL/PEI/TTL exhibited the highest decolorization efficiencies of Orange II and Malachite Green after 8 continuous uses at pH 5 and a temperature of 50 °C, reaching over 86%, and 46%, respectively. Moreover, PCL/PEI/TTL and PCL/PEI/TVL effectively degraded the 2,6-dichlorophenol phenolic compound at an optimal pH and temperature range and exhibited maximum removal efficiency of 52.6 ± 0.1% and 64.5 ± 7.6%, respectively. Our approach combines the advantageous properties of electrospun fiber material and immobilization strategy for the efficient use of industrial scale important enzymes such as laccase in various enzymatic applications.

A new biocomposite based on microbial autocrine laccase-rice straw: Preparation, characterization and application

The immobilization of laccase on crop residues is a promising way to treat water containing bisphenol A (BPA), but the high cost of commercially available solutions of this enzyme indicates a need for research into feasible cost-effective alternatives. Here, a new biocomposite was developed based on a microbial autocrine laccase process, where rice straw served as the sole carbon source and as a carrier mixed with Comamonas testosteroni FJ17 ( C. testosteroni FJ17). A laccase-rice straw biocomposite (RS-Lac) was prepared via a one-step synthesis and subsequently evaluated for the removal of BPA. A response surface methodology was used to optimize the synthesis of RS-Lac, where the subsequent removal efficiency of BPA (500 μg L −1 ) by RS-Lac biocomposite increased from 46.1 (unoptimized) to 57.0% (optimized). The molecular weight (Mw) of laccase was identified by SDS-PAGE to be 34 kDa. SEM, CLSM , FTIR, and XRD results confirmed laccase secreted by C. testosteroni FJ17 was coated with polysaccharides , and these were successfully immobilized on rice straw. The specific surface area of RS-Lac increased from 2.79 to 5.37 m 2 g −1 following synthesis optimization, and zeta potential analyzer indicated that it carried a strong negative charge. In addition, RS-Lac was also used to successfully remove estrone (E1), 17β-estradiol (E2), Cu(II), Sb(Ⅲ), As(Ⅲ), and As(Ⅴ) to varying degrees, with removal efficiencies of 68.7%, 66.4%, 77.5%, 84.0%, 83.7%, and 91.6%, respectively. This broad versatility indicated that RS-Lac has great potential as a low-cost biocomposite for treating wastewater. • A rice straw-i autocrine laccase biocomposite was prepared in one-step. • Various characterizations confirmed that crude laccase immobilized on rice straw. • The rice straw was coated with polysaccharides and immobilized laccase. • Degradation of bisphenol A (57%) to small molecular fragments in solution. • Heavy metal ions (>77.5%) and estrogen (>66.4%) were removed.

Biodegradation of chrysene and benzo[a]pyrene and removal of metals from naturally contaminated soil by isolated Trametes versicolor strain and laccase produced thereof

The objective of this study was to assess the degradation rates of chrysene and benzo[a]pyrene, as well as the removal of aluminium and iron from contaminated soil collected in the upper layer (0–30 cm) in Lagos, Southwest Nigeria. Trametes versicolor was isolated from this soil and used in degradation experiments, with plantain peels as support. After 8 weeks, 81.0% of chrysene degradation was achieved by T. versicolor , and by adding support this increased to 91.0%. Benzo[a]pyrene was less degradable, with 38.0% and 49.1% of degradation, respectively. Trametes versicolor was also capable of accumulate 46.1% of aluminium and 57.2% of iron. By adding plantain peels, these amounts increased to 48.2% and 61.8%, respectively. At the same time, laccase was produced by Trametes versicolor on plantain peels, achieving 37.8 U/g of crude laccase during SSF at 30 °C for 3 weeks. Laccase degradation experiments were set up in packed-bed reactor (PBR), with a constant feed of 21.6 mL/day of laccase, with and without mediators. In 35 days, 75.8% degradation of chrysene was achieved by laccase. The highest degradation was observed with ABTS (2,2 ′ -Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid diammonium salt) as mediator, 87.9%. Benzo[a]pyrene degradation with laccase reached 35.6%, raising to 38.8 % with ferulic acid as mediator. In addition, 99.2% of iron and 99.6% of aluminium was removed by laccase, being the treatment for this last mediated with ABTS. • T. versicolor efficiently degrades chrysene in soil in the presence of metals. • Laccase from T .versicolor efficiently removes metals in heavily contaminated soil. • Influence of metal co-contamination on PAH dissipation is studied in soil matrices.

Enzymatic degradation and metabolic pathway of acid blue 129 dye by crude laccase from newly isolated Trametes hirsuta EDN 082

Crude laccase from Trametes hirsuta EDN 082 was used in this study for the decolorization of anthraquinone and azo dyes. Characterization of degradation products from one selected dye, Acid Blue 129 (AB129), was investigated using liquid chromatography high-resolution mass spectrometry (LC-HRMS). The results showed that laccase from T. hirsuta EDN 082 (0.25 U/mL dyes) was able to decolourize AB 129, AB 113, RBBR, AB 25, RB4, and RB5 dyes with a decolorization efficiency of 88%, 73%, 71%, 72%, 42%, and 6%, respectively for 7 h. During the degradation of AB129 dye, nine metabolites were identified and characterized by electrospray ionization–liquid chromatography–mass spectrometry Quadrupole-Time of flight (ESI-LCMS-Q-TOF) analysis. Evaluation of peak area showed decreasing of the two metabolites, 1-amino-4-hydroxy-9,10-dioxo-9,10-dihydroanthracene-2-sulfonic acid (D2) and 2,4,6-trimethylaniline (D4) during 7 h reaction indicated these two compounds become the centre of the degradation after cleaving the AB129 dye, and from these results, metabolic pathways were proposed. This study offers the potency of laccase from T. hirsuta EDN 082 for bioremediation of synthetic dyes in the fields.

LACCASE PRODUCTION BY NEWLY ISOLATED GANODERMA LUCIDUM WITH SOLID STATE FERMENTATION CONDITIONS AND ITS USING FOR DYE DECOLORIZATION

Laccase production capacity of newly isolated fungus Ganoderma lucidum was studied during solid state fermentation on solid substrates. Because wheat bran was detected as the most effective solid substrate, effect of various culture parameters and some inducers on laccase production in wheat bran media was investigated. Wheat bran with moisture content of 75%, pH 5.0 and 30 °C was the most effective medium and 10 mM copper addition supported the highest amount of laccase. In glass tray fermenter 2973±220 U/L laccase activity was obtained. Crude laccase gave the highest activity at 70 °C. It was stable at 60°C for 6 hours and retained 37% activity at 70 °C for 2 hours. It decolorized 61% of Remazol Brilliant Blue R within 20 min. Results showed that this strain could produce high amount of laccase and suitable inducer such as copper could induce its laccase production. The crude laccase obtained could be used for textile dye decolorization applications.