Search

The food enzyme laccase (benzenediol:oxygen oxidoreductase, i.e. EC 1.10.3.2) is produced with the non‐genetically modified Trametes hirsuta strain AE‐OR by Amano Enzyme Inc. A safety evaluation of this food enzyme was made previously, in which EFSA concluded that this food enzyme did not give rise to safety concerns when used in six food manufacturing processes. Subsequently, the applicant has requested to extend its use to include three additional processes and to revise the use levels. In this assessment, EFSA updated the safety evaluation of this food enzyme when used in a total of nine food manufacturing processes. Dietary exposure to the food enzyme–total organic solids (TOS) was calculated to be up to 0.030 mg TOS/kg body weight (bw) per day in European populations. Using the no observed adverse effect level previously reported (862 mg TOS/kg bw per day, the highest dose tested), the Panel derived a margin of exposure of at least 28,733. Based on the data provided for the previous evaluation and the revised margin of exposure in the present evaluation, the Panel concluded that this food enzyme does not give rise to safety concerns under the revised intended conditions of use. [ABSTRACT FROM AUTHOR]

In this study, silver-coated magnetic nanoparticles were synthesized, functionalized with MUA, and covalently immobilized laccase enzyme. FTIR, TEM, EDX, ESR and CV techniques were used for characterization. The optimum pH for free and immobilized laccase was found to be 3.0 while the optimum temperatures were 45 °C and 55 °C, respectively. It was observed that Km and Vmax values decreased at the end of immobilization process. When thermal stability was investigated, it was found that, immobilized enzyme showed higher stability than free. It was observed that the immobilized laccase retained 58.13% of its initial activity after 10 consecutive uses. Additionally, immobilized laccase was used successfully in the removal of some dyes and phenolic compounds. These results showed that the silver-coated magnetic nanoparticles synthesized in this study can be used effectively in enzymatic bioremediation. [ABSTRACT FROM AUTHOR]

Microorganisms play an important role in the degradation of lignin. The structural characteristics of lignin, the latest development of microbial species (including fungi, actinomycetes, and bacteria), key enzymes (laccase, lignin peroxidase, manganese peroxidase, versatile peroxidase, dye-decolorizing peroxidases, etc.) and mechanism of lignin degradation by the key enzymes, and synthesized high value-added products (including lipids, polyhydroxyalkanoates, vanillin, and feed, etc.) are reviewed. However, the degradation rate of lignin is still relatively low, which gready limits its application. Some efficient methods are proposed for improving the degradation efficiency and transformation efficiency of lignin, including genetic engineering and metabolic engineering technologies. The main aim is to provide theoretical support for the comprehensive utilization of lignin. [ABSTRACT FROM AUTHOR]

White-rot fungi differentially express laccases when they encounter aromatic compounds. However, the underlying mechanisms are still being explored. Here, proteomics analysis revealed that in addition to increased laccase activity, proteins involved in sphingolipid metabolism and toluene degradation as well as some cytochrome P450s (CYP450s) were differentially expressed and significantly enriched during 48 h of o-toluidine exposure, in Trametes hirsuta AH28-2. Two Zn2Cys6-type transcription factors (TFs), TH8421 and TH4300, were upregulated. Bioinformatics docking and isothermal titration calorimetry assays showed that each of them could bind directly to o-toluidine and another aromatic monomer, guaiacol. Binding to aromatic compounds promoted the formation of TH8421/TH4300 heterodimers. TH8421 and TH4300 silencing in T. hirsuta AH28-2 led to decreased transcriptional levels and activities of LacA and LacB upon o-toluidine and guaiacol exposure. EMSA and ChIP-qPCR analysis further showed that TH8421 and TH4300 bound directly with the promoter regions of lacA and lacB containing CGG or CCG motifs. Furthermore, the two TFs were involved in direct and positive regulation of the transcription of some CYP450s. Together, TH8421 and TH4300, two key regulators found in T. hirsuta AH28-2, function as heterodimers to simultaneously trigger the expression of downstream laccases and intracellular enzymes. Monomeric aromatic compounds act as ligands to promote heterodimer formation and enhance the transcriptional activities of the two TFs. [ABSTRACT FROM AUTHOR]

Endophytic microbial communities colonize plants growing under various abiotic stress conditions. Candelilla (Euphorbia antisyphilitica Zucc.) is a shrub that develops functionally in arid and semi‐arid zones of Mexico; these conditions generate an association between the plant and the microorganisms, contributing to the production of enzymes as a defense mechanism for resistance to abiotic stress. The objective of this research was to isolate and identify endophyte fungi of candelilla and bioprospection of these endophytic fungi for enzyme production using candelilla by‐products. Fungi were isolated and identified using ITS1/ITS4 sequencing. Their potency index (PI) was evaluated in producing endoglucanase, xylanase, amylase, and laccase. Fermentation was carried out at 30°C for 8 days at 200 rpm, with measurements every 2 days, using candelilla by‐products as substrate. All fungi exhibited higher cellulase, amylase, and laccase activities on the 2nd, 6th, and 8th day of fermentation, respectively, of fermentation. The fungus Aspergillus niger ITD‐IN4.1 showed the highest amylase activity (246.84 U/mg), the genus Neurospora showed the highest cellulase activity, reaching up to 13.45 FPU/mg, and the strain Neurospora sp. ITD‐IN5.2 showed the highest laccase activity (3.46 U/mg). This work provides the first report on the endophytic diversity of E. antisyphilitica and its potential role in enzyme production. [ABSTRACT FROM AUTHOR]

Coriolopsis trogii is a basidiomycete fungus which utilizes a large array of lignin-modifying enzymes to colonize and decompose dead wood. Its extracellular enzymatic arsenal includes laccases, i.e., polyphenol oxidases of relevant interest for different industrial applications thanks to their ability to oxidize a diverse range of natural and synthetic compounds. In this work, the production of laccases in C. trogii MUT3379 was explored and improved. From an initial production of ca. 10,000 U L−1, the fermentation process was gradually optimized, reaching a final yield of ca. 200,000 U L−1. An SDS-PAGE analysis of the secretome highlighted the presence of a main protein of ca. 60 kDa showing laccase activity, which was designated as Lac3379-1 once its primary sequence was established by tandem mass spectrometry. The characterization of Lac3379-1 revealed a remarkable enzymatic stability in the presence of surfactants and solvents and a diversified activity on a broad range of substrates, positioning it as an interesting tool for diverse biotechnological applications. The high-yield and robust production process indicates C. trogii MUT3379 as a promising cell factory for laccases, offering new perspectives for industrial applications of lignin-modifying enzymes. [ABSTRACT FROM AUTHOR]

The growing demand in industrial and biotechnological settings for more efficient enzymes with enhanced biochemical features, particularly thermostability and thermotolerance, necessitates a timely response. Renowned for their versatility, thermostable enzymes offer significant promise across a range of applications, including agricultural, medicinal, and biotechnological domains. This comprehensive review summarizes the structural attributes, catalytic mechanisms, and connection between structural configuration and functional activity of two major classes of thermostable enzymes: α-amylases and laccases. These enzymes serve as valuable models for understanding the structural foundation behind the thermostability of proteins. By highlighting the commercial importance of thermostable enzymes and the interest these generate among researchers in further optimization and innovation, this article can greatly contribute to ongoing research on thermostable enzymes and aiding industries in optimizing production processes via immobilization, use of stabilizing additives, chemical modification, protein engineering (directed evolution and mutagenesis), and genetic engineering (through cloning and expression of thermostable genes). It also gives insights to the exploration of suitable strategies and factors for enhancing thermostability like increasing substrate affinity; introducing electrostatic, intramolecular, and intermolecular hydrophobic interactions; mitigating steric hindrance; increasing flexibility of an active site; and N- and C-terminal engineering, thus resulting in heightened multipronged stability and notable enhancements in the enzymes' industrial applicability. [ABSTRACT FROM AUTHOR]

BACKGROUND: One significant component of new, rapid economic development is the creation of biodegradable polymers. One of these biopolymers is polyhydroxyalkanoate (PHA). This biodegradable, thermoplastic and water‐insoluble storage polymer can be generated from sustainable carbon sources. PHA may be effectively used for treating wastewaters by immobilizing enzymes. For eliminating micropollutants along with many phenolic compounds, laccase is considered as a potential enzyme. Hence, it has been known to be highly effective for water purification procedures. However, adequate immobilization is required for laccase to perform efficient catalysis. The immobilization procedure increases laccase stability with respect to reusability, temperature, pH and storage, making it superior to free laccase. RESULT: In the present study, laccase was partially purified from Beauveria pseudobassiana PHF4 by gel filtration chromatography and further immobilized on PHA microbeads. The crude extract displayed specific activity of 19.08 U mg−1 and PHA microbeads demonstrated immobilization efficiency of 77.44%. Characterization of PHA microbeads by scanning electron microscopy showed an increase in their size from 3–5 μm to 5–6 μm after the immobilization. Furthermore, catechol biodegradation by immobilized laccase was analyzed using UV–visible spectrophotometry (84.25% in 10 h), which was also confirmed by high‐performance liquid chromatography (83.65% in 24 h). CONCLUSION: Iimmobilizing laccase on PHA microbeads can help to address the pollution and environmental damage that catechol and similar chemicals cause also in an ecofriendly manner. © 2024 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

Copyright of Journal of Henan University of Technology Natural Science Edition is the property of Henan University of Technology Journal Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to improve the remediation effect of oil contaminated soil, ceramic particle volcanic rock composite carrier was prepared by improving the stirring crosslinking method, and immobilization of microorganisms/ laccase. Afterwards, SEM, BET, FTIR, and soil biological characteristics were combined to analyze the properties of immobilized carriers and their differences in the remediation of petroleum contaminated soil. One of the results shows that the composite carrier of ceramic particles and volcanic rocks has an improved petroleum hydrocarbon adsorption performance by about 50% compared to a single carrier. At the same time, the immobilized carrier prepared increased its specific surface area by 3.1%-51.1% and pore volume by 8.6%-50.9%. The immobilized microbial load reaches the order of 109 cells/g. The proportion of living cells stored for 15 days reached 60.89%. The relative activity of immobilized laccase remains above 19% after 5 cycles of recycling, and about 56% after 30 days of storage. The highest remediation effect of soil petroleum hydrocarbons is 58.98% (immobilized bacteria enzyme complex preparation). Soil dehydrogenase, urease, catalase and polyphenol oxidase were significantly improved. And there is a significant positive correlation with petroleum hydrocarbons. The microbial structure analysis showed that adding immobilized carrier would change the soil microbial community structure and lead to the emergence of dominant species, including Pseudomonas, Virgibacillus and Oceanobacillus. [ABSTRACT FROM AUTHOR]

Plant-based protein is considered a sustainable protein source and has increased in demand recently. However, products containing plant-based proteins require further modification to achieve the desired functionalities akin to those present in animal protein products. This study aimed to investigate the effects of enzymes as cross-linking reagents on the physicochemical and functional properties of hybrid plant- and animal-based proteins in which lupin and whey proteins were chosen as representatives, respectively. They were hybridised through enzymatic cross-linking using two laccases (laccase R, derived from Rhus vernicifera and laccase T, derived from Trametes versicolor) and transglutaminase (TG). The cross-linking experiments were conducted by mixing aqueous solutions of lupin flour and whey protein concentrate powder in a ratio of 1:1 of protein content under the conditions of pH 7, 40 °C for 20 h and in the presence of laccase T, laccase R, or TG. The cross-linked mixtures were freeze-dried, and the powders obtained were assessed for their cross-linking pattern, colour, charge distribution (ζ-potential), particle size, thermal stability, morphology, solubility, foaming and emulsifying properties, and total amino acid content. The findings showed that cross-linking with laccase R significantly improved the protein solubility, emulsion stability and foaming ability of the mixture, whereas these functionalities were lower in the TG-treated mixture due to extensive cross-linking. Furthermore, the mixture treated with laccase T turned brownish in colour and showed a decrease in total amino acid content which could be due to the enzyme’s oxidative cross-linking mechanism. Also, the occurrence of cross-linking in the lupin and whey mixture was indicated by changes in other investigated parameters such as particle size, ζ-potential, etc., as compared to the control samples. The obtained results suggested that enzymatic cross-linking, depending on the type of enzyme used, could impact the physicochemical and functional properties of hybrid plant- and animal-based proteins, potentially influencing their applications in food. [ABSTRACT FROM AUTHOR]

An unresolved issue with plant-based meat analog (PBMA) products is their lower texture and juiciness than animal-derived meat products. Almost all commercial PBMA patties are constructed using methylcellulose (MC). Thus, this study aimed to develop better formulations of binding systems for PBMA patties that simulate the physical properties of beef patties than MC binder. We investigated the formulations of binding systems using crosslinking-catalyzed enzymes (transglutaminase [TG] and laccase [LC]) and 2–4 % carbohydrate binders (MC and sugar beet pectin [SBP]). Texture profile analysis using a rheometer and sensory scores by nine panelists revealed that TG-catalyzed PBMA patties with 3 % MC and LC-catalyzed PBMA patties with 4 % SBP were similar to beef patties than PBMA patties constructed with any MC concentration. These findings suggest that binding systems using crosslinking-catalyzed enzymes and carbohydrate binders could bridge the gap in physical properties between the current MC-based PBMA and beef patties. [ABSTRACT FROM AUTHOR]

Broad-spectrum biocatalysts enzymes, Laccases, have been implicated in the complete degradation of harmful pollutants into less-toxic compounds. In this study, two extracellularly produced Laccases were purified to homogeneity from two different Ascomycetes spp. Trichoderma lixii FLU1 (TlFLU1) and Talaromyces pinophilus FLU12 (TpFLU12). The purified enzymes are monomeric units, with a molecular mass of 44 kDa and 68.7 kDa for TlFLU1 and TpFLU12, respectively, on SDS-PAGE and zymogram. It reveals distinct properties beyond classic protein absorption at 270–280 nm, with TlFLU1's peak at 270 nm aligning with this typical range of type II Cu site (white Laccase), while TpFLU12's unique 600 nm peak signifies a type I Cu2+ site (blue Laccase), highlighting the diverse spectral fingerprints within the Laccase family. The Km and kcat values revealed that ABTS is the most suitable substrate as compared to 2,6-dimethoxyphenol, caffeic acid and guaiacol for both Laccases. The bioinformatics analysis revealed critical His, Ile, and Arg residues for copper binding at active sites, deviating from the traditional two His and a Cys motif in some Laccases. The predicted biological functions of the Laccases include oxidation–reduction, lignin metabolism, cellular metal ion homeostasis, phenylpropanoid catabolism, aromatic compound metabolism, cellulose metabolism, and biological adhesion. Additionally, investigation of degradation of polycyclic aromatic hydrocarbons (PAHs) by purified Laccases show significant reductions in residual concentrations of fluoranthene and anthracene after a 96-h incubation period. TlFLU1 Laccase achieved 39.0% and 44.9% transformation of fluoranthene and anthracene, respectively, while TpFLU12 Laccase achieved 47.2% and 50.0% transformation, respectively. The enzyme structure–function relationship study provided insights into the catalytic mechanism of these Laccases for possible biotechnological and industrial applications. [ABSTRACT FROM AUTHOR]

Phenoxy radical coupling reactions are widely used in nature for the synthesis of complex molecules such as lignin. Their use in the laboratory has great potential for the production of high value compounds from the polyphenol family. While the enzymes responsible for the generation of the radicals are well known, the behavior of the latter is still enigmatic and difficult to control in a reaction flask. Previous work in our laboratory using the enzymatic secretome of B. cinerea containing laccases has shown that incubation of stilbenes leads to dimers, while incubation of phenylpropanoids leads to dimers as well as larger coupling products. Building on these previous studies, this paper investigates the role of different structural features in phenoxy radical couplings. We first demonstrate that the presence of an exocyclic conjugated double bond plays a role in the generation of efficient reactions. In addition, we show that the formation of phenylpropanoid trimers and tetramers can proceed via a decarboxylation reaction that regenerates this reactive moiety. Lastly, this study investigates the reactivity of other phenolic compounds: stilbene dimers, a dihydro-stilbene, a 4-O-methyl-stilbene and a simple phenol with the enzymatic secretome of B. cinerea. The observed efficient dimerization reactions consistently correlate with the presence of a para-phenol conjugated to an exocyclic double bond. The absence of this structural feature leads to variable results, with some compounds showing low conversion or no reaction at all. This research has allowed the development of a controlled method for the synthesis of specific dimers and tetramers of phenylpropanoid derivatives and novel stilbene derivatives, as well as an understanding of features that can promote efficient radical coupling reactions. [ABSTRACT FROM AUTHOR]

Background: White-rot fungi are known to naturally produce high quantities of laccase, which exhibit commendable stability and catalytic efficiency. However, their laccase production does not meet the demands for industrial-scale applications. To address this limitation, it is crucial to optimize the conditions for laccase production. However, the regulatory mechanisms underlying different conditions remain unclear. This knowledge gap hinders the cost-effective application of laccases. Results: In this study, we utilized transcriptomic and metabolomic data to investigate a promising laccase producer, Cerrena unicolor 87613, cultivated with fructose as the carbon source. Our comprehensive analysis of differentially expressed genes (DEGs) and differentially abundant metabolites (DAMs) aimed to identify changes in cellular processes that could affect laccase production. As a result, we discovered a complex metabolic network primarily involving carbon metabolism and amino acid metabolism, which exhibited contrasting changes between transcription and metabolic patterns. Within this network, we identified five biomarkers, including succinate, serine, methionine, glutamate and reduced glutathione, that played crucial roles in co-determining laccase production levels. Conclusions: Our study proposed a complex metabolic network and identified key biomarkers that determine the production level of laccase in the commercially promising Cerrena unicolor 87613. These findings not only shed light on the regulatory mechanisms of carbon sources in laccase production, but also provide a theoretical foundation for enhancing laccase production through strategic reprogramming of metabolic pathways, especially related to the citrate cycle and specific amino acid metabolism. [ABSTRACT FROM AUTHOR]

Polypropylene (PP) is a major environmental problem in Malaysia because it has been ranked the 28th highest plastic polluter in the world (at 56kg per capita per year) in 2021. Landfilling is one of the most common ways of dealing with plastic because leachate may cause increased probability of cancer and neurological impairment in humans. The use of fungi in mycoremediation makes the process eco-friendly. In addition, fungi have a vast hyphal network and broader metabolic competence. The objective of this study was to investigate fungi remediation of PP via the detection of manganese peroxidase and laccase activity in Bushnell Haas Broth (BHB). PP degradation activity was measured via the activity of laccase and manganese peroxidase at a wavelength of 450nm and 610nm, respectively. Of the 17 species of fungi isolated from the Jeram landfill, 12 species of fungi showed growth in BHB with PP as the sole carbon source. Penicillium sp. 1, Aspergillus sp., Penicillium levitum, Talaromyces louisianensis, Aspergillus tamarii, Cunninghamella bertholletiae, Penicillium sp. 2 and Aspergillus niger demonstrated high and longer laccase activity, and these fungi could be considered as potential fungi. P. levitum, P. janthinellum, Penicillium sp, and T. louisianensis have high and longer MnP activity. In summary, P. levitum and T. louisianensis have a high and long duration of MnP and laccase activity in degrading PP, which can be developed and integrated into plastic waste management. [ABSTRACT FROM AUTHOR]

Nowadays, natural resources like lignocellulosic biomass are gaining more and more attention. This study was conducted to analyse chemical composition of dried and ground samples (500 μm) of various Algerian bioresources including alfa stems (AS), dry palms (DP), olive pomace (OP), pinecones (PC), and tomato waste (TW). AS exhibited the lowest lignin content (3.60 ± 0.60%), but the highest cellulose (58.30 ± 2.06%), and hemicellulose (20.00 ± 3.07%) levels. DP, OP, and PC had around 30% cellulose, and 10% hemicellulose. OP had the highest lignin content (29.00 ± 6.40%), while TW contained (15.70 ± 2.67% cellulose, 13.70 ± 0.002% hemicellulose, and 17.90 ± 4.00% lignin). Among 91 isolated microorganisms, nine were selected for cellulase, xylanase, and/or laccase production. The ability of Bacillus mojavensis to produce laccase and cellulase, as well as B. safensis to produce cellulase and xylanase, is being reported for the first time. In submerged conditions, TW was the most suitable substrate for enzyme production. In this conditions, T. versicolor K1 was the only strain able to produce laccase (4,170 ± 556 U/L). Additionally, Coniocheata hoffmannii P4 exhibited the highest cellulase activity (907.62 ± 26.22 U/L), and B. mojavensis Y3 the highest xylanase activity (612.73 ± 12.73 U/L). T. versicolor K1 culture showed reducing sugars accumulation of 18.87% compared to initial concentrations. Sucrose was the predominant sugar detected by HPLC analysis (13.44 ± 0.02 g/L). Our findings suggest that T. versicolor K1 holds promise for laccase production, while TW represents a suitable substrate for sucrose production. [ABSTRACT FROM AUTHOR]

Lactobionic acid (LBA) has diverse number of applications in pharmaceutical, food, chemical and nanotechnology fields. Bioproduction of LBA by bi-enzymatic cellobiose dehydrogenase (CDH)/laccase (LAC) is a system where CDH catalyses oxidation of lactose to LBA, whilst LAC has, at the same time, ability to regenerate the redox mediator as electron acceptor for CDH. In this study, CDH mutants derived from Phanerochaete chrysosporium produced in Pichia pastoris were used to determine LBA production rate with varying number of redox mediators. The highest specific productivity was observed for triple mutant CDH (tmCDH) for all redox mediators used in this study. The notable redox mediator was hydroquinone where specific productivity was 29.14 g L−1 kU−1 for tmCDH while specific productivity with DCIP was 27.2 g L−1 kU−1, with ABTS showed 19.1 g L−1 kU−1. Lactobionic acid production using bi-enzymatic system, CDH/LAC. Regeneration of different redox mediators. Recombinant mutants used in reaction system. [ABSTRACT FROM AUTHOR]

The genome of Trametes versicolor encodes multiple laccase isozymes, the expression of which is responsive to various conditions. Here, we set out to investigate the potential of orange peel extract as an inducer of laccase production in this white-rot fungus, in comparison to the previously identified inducing chemical compound, veratryl alcohol. For four geographically distinct T. versicolor strains, a positive correlation has been observed between their oxidative activity and incubation time in liquid cultures. The addition of 20% orange peel extract or 5 mM veratryl alcohol caused a rapid increase in the oxidative potential of T. versicolor M99 after 24 h, with a more pronounced effect observed for the orange peel extract. To elucidate the underlying molecular mechanisms of the induced laccase activity, a transcriptional gene expression analysis was performed for the seven individual laccase genes in T. versicolor, revealing the upregulation of several laccase genes in response to the addition of each inducer. Notably, the gene encoding TvLac5 demonstrated a substantial upregulation in response to the addition of 20% orange peel extract, likely contributing to the observed increase in its oxidative potential. In conclusion, our results demonstrate that orange peels are a promising agro-industrial side stream for implementation as inducing agents in large-scale laccase production with T. versicolor. [ABSTRACT FROM AUTHOR]

Alginate is a naturally occurring polymer derived from brown algae biomass, which has numerous applications in various fields. Chemical modification of alginate is widely used to improve alginate's physicochemical properties and provide new potential for multiple applications. In this article, we modified alginate with L-DOPA, using periodate oxidation and reductive amination, to obtain more suitable biopolymer for biocatalyst immobilization and hydrogel formation. Obtained modified alginate was used for the immobilization of laccase on cell walls. For this purpose, laccase from Streptomyces cyaneus was expressed on the surface of Saccharomyces cerevisiae EBY100 cells. The obtained cell wall laccase was immobilized within L-DOPA-alginate beads by crosslinking the L-DOPA-alginate with calcium ions and laccase. The effect of additional crosslinking of beads by green light-induced photopolymerization with eosin Y was investigated. The immobilized laccase systems were used for dye decolorization and investigated in multiple treatment processes. Beads with L-DOPA-alginate with a higher degree of modification (5.0 mol%) showed higher enzymatic activity and better decolorization efficiency than those with a lower degree of modification (2.5 mol%). Obtained immobilized biocatalysts are suitable for decolorizing dye Evans Blue due to their high efficiency and reusability. [ABSTRACT FROM AUTHOR]

Heavy metal contamination is one of the key environmental complications. Due to some disadvantages of conventional methods, the use of active organisms is becoming more popular technique to remove it. In the present study, primarily 35 bacterial strains were discovered in metal containing media. After being identified resistance power to different copper concentrations (100–1000 mg/l), JRHM33 had the highest level of resistance up to 1000 mg/l of copper. Using the 16S rRNA sequencing, bacterial strain JRHM33 was discovered and revealed 99% similarity to pseudomonas aeruginosa. Sequencing and bioinformatics study using conserved domain analysis supported the laccase gene is present in JRHM33 and has classification as a member of the multicopper oxidase superfamily, which has reduction capacity of metal ions. Analysis of phenotype microarray (PM) technology provides an insight into the metabolic profiling of microbial cell into Pseudomonas aeruginosa JRHM33. Furthermore, Using the central composite design of response surface methodology (CCD-RSM), the successive optimization of the process parameters was attempted for the maximum reduction of the copper. Maximum 68.71% Cu reduction was achieved at 6.71 pH, 90.61 min of incubation time, 5 ml of inoculum size, and 113 rpm of agitation. The generated model has R² value of 0.9834, indicating that the ANOVA gave it a very significant result. The findings of the validation experiment showed a remarkable similarity between the projected and experimental results. It is determined that bacterial strains isolated from metal-contaminated effluent employ their natural capacity to change toxic heavy metals into less harmful or nontoxic forms. [ABSTRACT FROM AUTHOR]

The presence of antibiotics in water systems and drinking water has detrimental effects on various organisms and poses health risks to both animals and humans. This study describes a sustainable approach using laccases to remove ciprofloxacin from water solutions. Laccases produced by monoculture of Trametes villosa and in co-culture with Pycnoporus sanguineus were immobilized using the method of cross-linked enzyme aggregates (CLEAs). The immobilization process was statistically optimized, and the biocatalysts were characterized and applied for biodegradation of ciprofloxacin at different concentrations. Laccase production was enhanced in co-culture conditions, yielding isoforms of molecular masses ranging from 55 to 45 kDa. Optimum conditions for immobilizing laccases by CLEAs were achieved with ammonium sulfate as a precipitant and glutaraldehyde as a cross-linker. Immobilization improved the thermal stability of the enzymes at 40 °C and 55 °C, and both forms of laccase CLEAs retained approximately 38% of their initial activity after five reuse cycles. Free and immobilized laccases demonstrated comparable efficiency in removing ciprofloxacin from aqueous solutions (at 2.5 mg L−1) with a 53–62% removal rate in the presence of 4-hydroxybenzoic acid as a natural redox mediator. The degradation of ciprofloxacin by laccases also reduced its antimicrobial activity against Escherichia coli. [Display omitted] • Co-culture of Trametes villosa with Pycnoporus sanguineus enhances laccase production. • Laccases immobilized as CLEAS exhibited improved thermal stability and reusability. • Free and immobilized laccases effectively catalyzed the degradation of ciprofloxacin • Enzymatic biodegradation of ciprofloxacin reduced its action against Escherichia coli. [ABSTRACT FROM AUTHOR]

Commercial direct dyes are frequently employed in the dyeing of Jumputan, a traditional craft originating from South Sumatra, Indonesia. The introduction of synthetic dyes into the environment can have a detrimental impact on ecosystem stability, necessitating the implementation of remedial measures. There has been a growing interest in the utilization of White Rot Fungi (WRF) as a viable biological agent for the purpose of decolorizing and detoxifying synthetic colors. However, it is imperative to investigate the isolated WRF from Berbak-Sembilang National Park (TNBS) due to the varying capacities of decolorization and detoxification exhibited by each WRF. The study involved 5 WRF from TNBS screened in solid media, and grown in a liquid medium containing commercial direct dyes (direct turquoise, direct orange and direct yellow). WRF grown on liquid medium contains a single dye, mixture dyes and temperature characterization. It measured decolorization, biomass and enzyme activities. Toxicity is measured by the BSLT method. The findings indicated that 3 specific fungi, namely Phellinus noxius (BRB 11), Lentinus sajor-caju (BRB 12) and Leotrametes menziesii (BRB 73), exhibited a significant capacity to remove the color from both individual and mixture of direct dyes through the production of laccase and MnP enzymes. The optimal temperature for decolorization of the mixture of direct dyes was 35 °C for BRB 11 (61.4 %) and BRB 73 (60.7 %), whereas BRB 12 (47.4 %) exhibited optimal temperature at 30 °C. The toxicity assay conducted using A. salina showed a progressive rise in the LC50 value, from 15.37 mgL-1 in the control group to a range of 21.63 - 35.84 mgL-1 in the treated group, indicating a detoxification process. However, the most toxic isolate was BRB 12. This study proposes the potential of 2 isolates, Phellinus noxius (BRB 11) and Leotrametes menziesii BRB 73, from TNBS for degradation of single and mixture dye wastewater in the environment. [ABSTRACT FROM AUTHOR]

Bacterial infections are among the most critical global health challenges that seriously threaten the security of human. To address this issue, a biocompatible engineered living hydrogel patch was developed by co-embedding engineered photothermal bacteria (EM), photosensitizer (porphyrin) and reactive oxygen species amplifier (laccase) in a protein hydrogel. Remarkably, the genetice engineered bacteria can express melanin granules in vivo and this allows them to exhibit photothermal response upon being exposed to NIR-II laser (1064 nm) irradiation. Besides, electrostatically adhered tetramethylpyridinium porphyrin (TMPyP) on the bacterial surface and encapsulated laccase (Lac) in protein gel can generate highly toxic singlet oxygen (1O 2) and hydroxyl radical (·OH) in the presence of visible light and lignin, respectively. Interestingly, the engineered bacteria hydrogel patch (EMTL@Gel) was successfully applied in synergistic photothermal, photodynamic and chemodynamic therapy, in which it was able to efficiently treat bacterial infection in mouse wounds and enhance wound healing. This work demonstrates the concept of "fighting bacteria with bacteria" combining bacterial engineering and material engineering into an engineered living hydrogel path that can synergistically boost the therapeutic outcome. Genetically engineered bacteria produce melanin granules in vivo , exhibiting remarkable photothermal properties. These bacteria, along with a photosensitizer (TMPyP) and a reactive oxygen species amplifier (laccase), are incorporated into a biocompatible protein hydrogel patch. Under visible light, the patch generates toxic singlet oxygen (1O 2) and hydroxyl radical (·OH), demonstrates outstanding synergistic effects in photothermal, photodynamic, and chemodynamic therapy, effectively treating bacterial infections and promoting wound healing in mice. [Display omitted] [ABSTRACT FROM AUTHOR]

Discharge of the exhausted dye bath at the end of dyeing imposes a huge waste-water load, necessitating the use of fresh water for further processing. Due to the limited availability of fresh water, industries are compelled to remove the dyes from drained-out liquor to protect the environment and recycle the treated water for future processing. Discharged dyes create a film or layer of color on the water's surface, impeding the natural breakdown of substances and harm aquatic organisms. A significant proportion of effluent comprises synthetic dyes from azo, anthraquinone, triphenylmethane, indigo, and other groups. Several azo dyes and their cleaved by-products have been discovered to impact human health. Various established techniques are commonly employed to remove the color from dye; however, they have inherent restrictions. Due to increased demand, there is a growing need to explore cost-effective alternative treatments, such as biological integrated systems. The utilization of laccase for the decolorization of dyes presents a possible technological solution to address the drawbacks associated with current approaches. These enzymes can chemically react with and break down diverse substances. Laccases have been verified for their capacity to break down synthetic dyes in wastewater, resulting in the degradation of less hazardous products than the original dyes. This study examines the advantages and disadvantages of different technologies used to remove color from dyes. It also discusses the degradation mechanisms of several synthetic dyes catalyzed by laccase and the impact of factors, such as temperature, pH, dye concentration, etc. Additionally, the most recent studies on decolorization utilizing laccase are reviewed. [ABSTRACT FROM AUTHOR]

Mesotrione (MES) is a new environmental pollutant. Some reports have indicated that microbial enzymes could be utilized for MES degradation. Laccase is a green biocatalyst whose potential use in environmental pollutant detoxification has been considered limited due to its poor stability and reusability. However, these issues may be addressed using enzyme immobilization. In the present study, we sought to optimize conditions for laccase immobilization, to analyze and characterize the characteristics of the immobilized laccase, and to compare its enzymatic properties to those of free laccase. In addition, we studied the ability of laccase to degrade MES, and analyzed the metabolic pathway of MES degradation by immobilized laccase. The results demonstrated that granular zinc oxide material (G-ZnO) was successfully used as the carrier for immobilization. G-ZnO@Lac demonstrated the highest recovery of enzyme activity and exhibited significantly improved stability compared with free laccase. Storage stability was also significantly improved, with the relative enzyme activity of G-ZnO@Lac remaining at about 54% after 28 days of storage (compared with only 12% for free laccase). The optimal conditions for the degradation of MES by G-ZnO@Lac were found to be 10 mg, 6 h, 30 °C, and pH 4; under these conditions, a degradation rate of 73.25% was attained. The findings of this study provide a theoretical reference for the laccase treatment of 4-hy-droxyphenylpyruvate dioxygenase (HPPD)-inhibiting herbicide contamination. [ABSTRACT FROM AUTHOR]

Purpose: Although the combined plant-biochar remediation in improving soil contaminated by polycyclic aromatic hydrocarbons (PAHs) is considered efficient (Singha and Pandey in Crit Rev Biotechnol 41:749–766, 2021), the potential for application remains poorly known. This study used clones of Buchloe dactyloides to evaluate the effects of biochar on the capability of phytoremediation and rhizosphere soil contaminated with PAH. Materials and methods: Pot experiments were conducted to assess the effects of biochar on growth physiological parameters of B. dactyloides growth, accumulation of PAHs in B. dactyloides, and soil environment. Results and discussion: The results showed that the application of biochar increased the levels of antioxidants (free proline, glutathione, and ascorbic acid), antioxidant enzymes (catalase and laccase), and phytohormones (abscisic acid, indole acetic acid, jasmonic acid, salicylic acid, and gibberellin), decreased the accumulation of reactive oxygen species and lipid peroxidation in the roots, thereby enhancing the antioxidant defense ability and improving PAHs tolerance in roots of B. dactyloides. Moreover, the activities of enzymes (catalase, dehydrogenases, urease and protease) and soil nutrients in the rhizosphere soil were significantly increased, the content of PAHs decreased, and the health of the rhizosphere soil was improved. Conclusions: Biochar treatment promoted the accumulation of PAHs, improved soil environment and significantly enhanced the effects of phytoremediation. Therefore, the combined application of B. dactyloides and biochar can be considered as a feasible approach for the phytoremediation of PAH-contaminated soil. [ABSTRACT FROM AUTHOR]

Scarcity of water is becoming a big issue. Most of the water is used in industrial sectors including pharmaceutical, food, textiles, leather, and cosmetics. Industrial effluent water is unable to treat and reuse due to their intricate nature. Effluent water contains synthetic azo dyes since they employ synthetic azo dyes as a major coloring agent. Existing approaches are ineffective in treating effluent containing synthetic azo dyes. Synthetic azo dyes containing effluent water can be treated biologically to overcome the drawbacks of physical and chemical processes. In this research work, novel organism was isolated from tannery effluent water. Isolated organisms were screened and selected for effective degradation of azo dyes. One such organism is Citrobacter freundii which effectively degrade the effluent water containing synthetic azo dyes and allowing it to reuse for variety of purpose. Phytotoxicity study of the treated water was carried out and the study confirms non toxicity nature of the treated water. In‐silico screening was carried out to test the interaction efficacy of enzymes such as Laccase, Azo reductase, and peroxidase which are responsible for effective dye degradation with synthetic azo dyes. In silico studies showed better interactions between synthetic azo dyes and enzymes. This is the novel report on showing the effective degradation of synthetic azo yellow dye by using C. freundii isolated from tannery effluent. [ABSTRACT FROM AUTHOR]

Copyright of International Journal of Advances in Engineering & Pure Sciences is the property of Marmara University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the Western Himalayas, the turnover of litterfall for the economically important tree species Picea smithiana (spruce) is very high (9708.17 ± 1341.07 kg/ha/y), and the decomposition rates (decay constant – k) are also very low ranging from 0.221 to 0.294. Accordingly, 10–13 years is required to decompose 95% of the total litter in these forests. This high turnover of litter, coupled with slow decomposition rates, is the main hindrance in the natural establishment of this coniferous species. The regeneration of these forests is not keeping pace with the removal of tree species, and this problem has resulted in the depletion of growing stock over a large area. Keeping in view the economic importance of this tree species and the poor regeneration caused by the accumulation of litter, this study aimed to isolate Trichoderma, owing to its fast-growing nature, from the rhizosphere of P.smithiana to evaluate its degradation potential to manage the leaf litter by composting to convert it to a more usable product called compost which can be supplemented to the same ecosystem to ameliorate the soil quality and growth of the trees. The Trichoderma was qualitatively screened for its enzymatic activity based on forming a hydrolytic zone. The results revealed that out of six enzymes screened, it was found to be positive for four enzymes: Amylase (29 ± 2.08 mm), lipase (25 ± 1.52 mm), laccase (85 ± 2.64 mm), and cellulase (39 ± 2.08 mm). Due to the ability of Trichoderma to produce cellulase and laccase enzymes, it can be inferred that it can degrade the main components of litter, that is, cellulose and lignin. [ABSTRACT FROM AUTHOR]

Edible fungi have certain photo-sensitivity during the mushroom emergence stage, but there have been few relevant studies on the responses of Ganoderma lucidum to different light irradiation conditions. Ganoderma lucidum were planted in an environmentally controllable mushroom room with different light supply modes that were, respectively, continuous white light (CK), red light (R), green light (G), blue light (B), and intermittent red light (R-), green light (G-), and blue light (B-), with a total light intensity of 15 μmol·m−2·s−1 and a light/dark (L/D) period of 12 h/12 h for each treatment. The interval in intermittent light treatments was 30 min. The optimal light supply mode suitable for the growth of Ganoderma lucidum was explored by analyzing the characteristics, nutritional quality, and extracellular enzyme activity in mushrooms exposed to different light treatments. The results showed that red light (whether in continuous or intermittent supply modes) inhibited the fruiting body differentiation of Ganoderma lucidum, showing delayed differentiation or complete undifferentiation. The highest stipe length and pileus diameter of fruiting bodies were detected under G- treatment, which were, respectively, increased by 71.3% and 3.2% relative to the control. The highest weight of fruiting bodies was detected under G treatment, which was significantly increased by 21.4% compared to the control (p < 0.05). Intermittent light mode seemed to be more conducive to the size development of the fruiting body, while continuous light mode was beneficial for increasing the weight. The highest contents of crude protein and total triterpenes in pileus were detected under G treatment (significantly 14.9% and 28.1% higher than the control, respectively), while that of the crude polysaccharide was detected under G- treatment (significantly 35.7% higher than the control) (p < 0.05). The highest activities of extracellular enzymes such as cellulase, hemicellulase, laccase, lignin peroxidase, and amylase were detected in fruiting bodies subjected to G treatment, which were significantly increased by 11.9%~30.7% in the pileus and 9.5%~44.5% in the stipe. Green light might increase the weight and nutrient accumulation in the pileus of Ganoderma lucidum via up-regulating the extracellular enzyme activities. This study provides an effective light supply strategy for regulating the light environment in the industrial production of Ganoderma lucidum. [ABSTRACT FROM AUTHOR]

The emergence of environmental endocrine disruptor chlorobenzene (CB) in surface water and its potential environmental impacts have attracted serious global attention. It is still very difficult to achieve effective degradation of it by catalytic oxidation process under mild conditions. Here, an optimized method for degrading CB in aqueous solution using Trametes versicolor laccase and surfactant-assisted laccase-mediator (SALM) system was investigated. The use of a Tween 80 surfactant enhanced the solubility of CB and promoted its efficient degradation. Under favorable conditions, the SALM system yielded a degradation efficiency of 43.5% and a dechlorination efficiency of 41.55% for CB (25 mg/L) within 24 h. The possible degradation pathway of CB by this system was speculated by detecting the intermediates produced during the reaction. The outcome of the proliferation assays on MCF-7 human breast cancer cells demonstrated a reduction in the estrogenic activity of the CB solution following treatment with the SALM system. Furthermore, the influence of the quantity and positional variation of chlorine substituents on the degradation process was methodically investigated. Moreover, molecular analyses were employed to study the detailed interaction mechanism between laccase and CB, which revealed that the hydrophobic interaction contributed dominantly to binding process. These findings provide an efficient and environmentally friendly degradation system for the development of purification strategies for halogenated pollutants.

A variety of important agricultural crops host fungi from the Aspergillus genus can produce cancerogenic secondary metabolites such as aflatoxins. Consequently, novel strategies for detoxification and their removal from food and feed chains are required. Here, detoxification of Aflatoxin B1 (AFB1) by the Bacillus subtilis multi-copper oxidase CotA (BsCotA) was investigated. This laccase was recombinantly produced in E. coli while codon optimization led to duplication of the amount of active protein obtained. CuCl2 was added to the cultivation medium leading to a 25-fold increase of Vmax corresponding to improved incorporation of Cu2+ into the enzyme protein which is essential for the catalytic reaction. To avoid potential cytotoxicity of Cu2+, cultivation was performed at microaerobic conditions indeed leading to 100x more functional protein when compared to standard aerobic conditions. This was indicated by an increase of Vmax from 0.30 ± 0.02 to 33.56 ± 2.02 U/mg. Degradation kinetics of AFB1 using HPLC with fluorescence detection (HPLC-FLD) analysis indicated a theoretical substrate saturation above solubility in water. At a relatively high concentration of 500 μg/L, AFB1 was decomposed at 10.75 μg/Lh (0.17 nmol*min−1*mg−1) at a dosage of 0.2 μM BsCotA. AFQ1 and epi-AFQ1 were identified as the initial oxidation products according to mass spectrometry (i.e., HPLC-MS, HPLC-QTOF). None of these molecules were substrates for laccase but both decomposed in buffer. However, decomposition does not seem to be due to hydration of the vinyl ether in the terminal furan ring. Genotoxicity of the formed AFB1 was assessed in several dilutions based on the de-repression of the bacterial SOS response to DNA damage indicating about 80-times reduction in toxicity when compared to AFQ1. The results of this study indicate that BsCotA has high potential for the biological detoxification of aflatoxin B1.

For the first time, we used laccase (LA) and hydrogen peroxide (H2O2) in supercritical fluid of carbon dioxide (SCF-CO2) to develop a method of bleaching cashmere fiber production in an ecofriendly way. The obtained results found that the whiteness of the cashmere was improved significantly involving a high bleaching efficient with this method, as well as influenced notably by the dosages of H2O2 and LA, bleaching temperature, pressure and duration. Various natural colorants on the cashmere sample were effectively decomposed and removed by the bleaching ingredients from the H2O2 and biologic catalyst of LA via an efficient transfer of those species onto cashmere surfaces from (H2O2 + LA+PEG1000 + H2O)/SCF-CO2 system. Particularly, this supercritical bleaching method with LA and H2O2 in SCF-CO2 reduced the number of damages to the cashmere fibers. Furthermore, we also successfully validated the supercritical removal of colorants by using X-ray energy spectroscopy (EDS) and scanning electron microscopy (SEM) analysis. Strength measurements and thermogravimetric (TG) and differential thermogravimetric (DTG) analysis demonstrate that supercritical bleaching had a reduced impact on the thermal and mechanical properties of the cashmere fiber. An optimized enzymatic-oxygen bleaching process in SCF-CO2 was further recommended by accompanying with a high whiteness value at 83.36 and an acceptable alkali solubility at 15.55 %. This developed supercritical bleaching method is prospective to be utilized for clear production of cashmere fibers by avoiding an extensive use of chemicals and the generation of heavy wastewater, as well as with less or non-effluent discharge.

Ganoderma, a well-known genus in the Ganodermataceae family, has caused the extinction of several tree species due to its pathogenicity. This study explored the pathogenic effect of a newly identified Ganoderma species on trees and its competitive efficiency against Trichoderma species. Ganoderma camelum sp. nov. is characterized by small sessile basidiomata and a velvety, soft, camel-brown pileus. Phylogenetic analysis and ITS rDNA sequences indicated that the species were Trichoderma and Ganoderma camelum. Both fungal species competed antagonistically by secreting laccase. The laccase activity of G. camelum, with a value of 8.3 ± 4.0 U/mL, demonstrated the highest competitive activity against Trichoderma species. The laccase produced by T. atroviride (2.62 U/mL) was most effective in countering the pathogenic action of the novel G. camelum. The molecular weights of laccase were determined using SDS-PAGE (62.0 kDa for G. camelum and 57.0 kDa for T. atroviride). Due to the white rot induced by this Ganoderma species in the host tree, G. camelum showed the highest percentage inhibition of radial growth (76.3%) compared to T. atroviride (28.7%). This study aimed to evaluate the competitive antagonistic activity of Ganoderma and Trichoderma on malt extract agar media in the context of white rot disease in the host tree. This study concluded that the laccase from G. camelum caused weight loss in rubber wood blocks through laccase action, indicating tissue injury in the host species. Therefore, it was also concluded that G. camelum was more effective in pathogenic action of the host and resisted the biological action of T. atroviride. In principal components analysis (PCA), all the species associated with laccase exhibited a very strong influence on the variability of the system. The PIRG rate (percentage inhibition of radial growth) was strongly and positively correlated with laccase activity.

Abstract Background Azo dyes represent a common textile dye preferred for its high stability on fabrics in various harsh conditions. Although these dyes pose high-risk levels for all biological forms, fungal laccase is known as a green catalyst for its ability to oxidize numerous dyes. Methods Trichoderma isolates were identified and tested for laccase production. Laccase production was optimized using Plackett–Burman Design. Laccase molecular weight and the kinetic properties of the enzyme, including Km and Vmax, pH, temperature, and ionic strength, were detected. Azo dye removal efficiency by laccase enzyme was detected for Congo red, methylene blue, and methyl orange. Results Eight out of nine Trichoderma isolates were laccase producers. Laccase production efficiency was optimized by the superior strain T. harzianum PP389612, increasing production from 1.6 to 2.89 U/ml. In SDS-PAGE, purified laccases appear as a single protein band with a molecular weight of 41.00 kDa. Km and Vmax values were 146.12 μmol guaiacol and 3.82 μmol guaiacol/min. Its activity was stable in the pH range of 5–7, with an optimum temperature range of 40 to 50 °C, optimum ionic strength of 50 mM NaCl, and thermostability properties up to 90 °C. The decolorization efficiency of laccase was increased by increasing the time and reached its maximum after 72 h. The highest efficiency was achieved in Congo red decolorization, which reached 99% after 72 h, followed by methylene blue at 72%, while methyl orange decolorization efficiency was 68.5%. Conclusion Trichoderma laccase can be used as an effective natural bio-agent for dye removal because it is stable and removes colors very well.

为促进漆酶在花生饼粕中黄曲霉毒素B1（AFB1）脱除中的实际应用，以霉变花生饼为实验对象，利用漆酶降解AFB1，考察加酶量、体系pH、反应温度、反应时间及料液比对AFB1降解率的影响，优化漆酶降解花生饼中AFB1的工艺条件，并通过分子对接分析漆酶与AFB1的相互作用方式。结果表明：漆酶降解花生饼中AFB1的最优工艺条件为加酶量5 U/g、体系pH 6.0、反应时间48 h、反应温度45 ℃、料液比1∶ 10，在此条件下漆酶对花生饼中AFB1的降解率高达83.5%，AFB1残留量为15.8 μg/kg，符合国标要求（≤50 μg/kg）；分子对接分析表明AFB1与漆酶活性空腔中的氨基酸残基His109、Ser110、His111、Ser113、His452、Asp456间形成了氢键网络，漆酶降解AFB1的机制可能与该氢键网络有关。综上，漆酶对花生饼中AFB1具有高效的降解活性，在发霉花生饼脱毒处理中有较大应用前景。In order to promote the practical application of laccase in the removal of aflatoxin B1 (AFB1) in peanut cake/meal, moldy peanut cake was used as the experimental object to degrade AFB1 by laccase. The effects of enzyme dosage, system pH, reaction temperature, reaction time and solid-liquid ratio on the degradation rate of AFB1 were investigated, and the process conditions for the degradation of AFB1 in peanut cake by laccase were optimized. The interaction model between laccase and AFB1 was analyzed by molecular docking. The results showed that the optimal conditions for the degradation of AFB1 in peanut cake by laccase were obtained as follows: enzyme dosage 5 U/g, system pH 6.0, reaction time 48 h, reaction temperature 45 ℃ and solid-liquid ratio 1∶ 10. Under these conditions, the degradation rate of AFB1 in peanut cake was as high as 83.5%, and the residual amount of AFB1 was 15.8 μg/kg, which met the requirements of national standard(≤50 μg/kg). Molecular docking results showed that a hydrogen bond network was formed between AFB1 and the amino acid residues His109, Ser110, His111, Ser113, His452 and Asp456 in the active cavity of laccase. The mechanism of degradation of AFB1 by laccase might be related to the hydrogen bond network. In summary, laccase has high degradability to AFB1, which has great application prospect in detoxification treatment of moldy peanut cake.

The main reasons that make mankind look for new sources of energy are decreasing dependence on fossil fuels and reducing pollution. Wastewater treatment with the help of microbial fuel cells is an area where these two goals can be combined. Microbial fuel cells, in which microorganisms catalyze the oxidation of organic substances, represent a new and promising alternative for electricity generation. The creation of an efficient cathode in such systems is the important problem. It is evident that in these applications an oxygen (air) electrode is a promising cathode. In this study, the oxygen biocathode based on the laccase enzyme Pleurotus ostreatus HK-35 was developed and its electrochemical properties were studied depending on the immobilization method of the enzyme on the surface of a carbon-graphite electrode and the type of the electrolyte. It was experimentally established that laccase injection using a sol-gel matrix was the effective method for immobilizing laccase on the surface of a carbon-graphite electrode. It was shown that the more efficient operation of the laccase-based biocathode was observed in a phosphate-citrate (pH 4.0) buffer solution, i.e., in an acidic environment.

Abstract Laccases are multicopper oxidases able to oxidize several phenolic compounds and find application in numerous industrial applications. Among laccase producers, white-rot fungi represent a valuable source of multiple isoforms and isoenzymes of these multicopper oxidases. Here we describe the identification, biochemical characterization, and application of laccase 2 from Trametes polyzona (TP-Lac2), a basidiomycete fungus emerged among others that have been screened by plate assay. This enzyme has an optimal temperature of 50 °C and in acidic conditions it is able to oxidize both phenolic and non-phenolic compounds. The ability of TP-Lac2 to decolorize textile dyes was tested in the presence of natural and synthetic mediators at 30 °C and 50 °C. Our results indicate that TP-Lac2 most efficiently decolorizes (decolorization rate > 75%) malachite green oxalate, orange G, amido black10B and bromocresol purple in the presence of acetosyringone and 2,2′-azinobis (3-ethylbenzthiazoline-6-sulfonate)—ABTS. Overall, the laccase mediator system consisting of TP-Lac2 and the natural mediator acetosyringone has potential as an environmentally friendly alternative for wastewater treatment in the textile industry.

Abstract Background EnZolv is a novel enzyme-based, eco-friendly biomass pretreatment process that has shown great potential in the field of textile engineering and biotechnology. It employs laccase from Hexagonia hirta MSF2 and 2% ethanol in the process of delignification. The process is designed to evaluate optimal conditions to remove lignin and other impurities from cotton spinning mill waste (CSMW), without compromising the quality and strength of the fibers. CSMW is a low-cost and readily available source of cellulose, making it an ideal candidate for delignification using EnZolv. By optimizing the pretreatment conditions and harnessing the potential of enzymatic delignification, this research aims to contribute to more sustainable and efficient ways of utilizing lignocellulosic biomass in various industries for the production of biochemical and bioproducts. Results The present study emphasizes the EnZolv pretreatment in the delignification of cotton spinning mill wastes irrespective of the cellulose content. EnZolv process parameters such as, moisture content, enzyme load, incubation time, incubation temperature, and shaking speed were optimized. Under pre-optimized conditions, the percent lignin reduction was 61.34%, 61.64%, 41.85%, 35.34%, and 35.83% in blowroom droppings (BD), flat strips (FS), lickerin fly (LF), microdust (MD) and comber noils (CN), respectively. Using response surface methodology (RSM), the statistically optimized EnZolv pretreatment conditions showed lignin reduction of 59.16%, 62.88%, 48.26%, 34.64%, and 45.99% in BD, FS, LF, MD, and CN, respectively. Conclusion Traditional chemical-based pretreatment methods often involve harsh chemicals and high energy consumption, which can have detrimental effects on the environment. In contrast, EnZolv offers a greener approach by utilizing enzymes that are biodegradable and more environmentally friendly. The resulting fibers from EnZolv treatment exhibit improved properties that make them suitable for various applications. Some of the key properties include enhanced cellulose recovery, reduced lignin content, and improved biophysical and structural characteristics. These improvements can contribute to the fiber's performance and processability in different industries and future thrust for the production of cellulose-derived and lignin-derived bioproducts. Graphical Abstract

Industrial wastewater often contains harmful dyes, posing significant environmental challenges. This study used computational tools to investigate the interactions between the low-degradability Azo dye, Reactive Blue 19, and laccase enzyme from two fungi species, Lentinus sp. WR2 and Trametes versicolor, as well as the protein Xyn5B (GH30) from Bacillus sp. BP7. Physiochemical characterization indicated acidic properties for Lentinus sp. WR2 and T. versicolor, while basic characteristics for Bacillus sp. BP7. Secondary structure (SOPMA analysis) revealed that most laccases had random coiling, enhancing protein flexibility. The negative GRAVY index revealed favorable water interaction for Lentinus sp. WR2 and Bacillus sp. BP7. The ERRAT plot validated the laccase 3D structure. The molecular docking results were compared using active site prediction and docking score. Lentinus sp. WR2 is linked with Reactive Blue 19 through a single residual amino acid THR 168; T. versicolor is linked through GLY 101, TRP 98, and TRP 512; and Bacillus sp. BP7 exhibited four linkages: VAL 262, TYR 263, TRP 117, and THR 260. The molecular docking results showed that Xyn5B demonstrated laccase activity and bound effectively with Reactive Blue 19, outperforming a commonly used fungal laccase in dye degradation. These findings enhance our understanding of enzyme-substrate interactions and highlight the potential of Xyn5B in eco-friendly dye degradation.

Phlebia radiata is a widespread white-rot basidiomycete fungus with significance in diverse biotechnological applications due to its ability to degrade aromatic compounds, xenobiotics, and lignin using an assortment of oxidative enzymes including laccase. In this work, a chemical screen with 480 conditions was conducted to identify chemical inducers of laccase expression in P. radiata. Among the chemicals tested, phenothiazines were observed to induce laccase activity in P. radiata, with promethazine being the strongest laccase inducer of the phenothiazine-derived compounds examined. Secretomes produced by promethazine-treated P. radiata exhibited increased laccase protein abundance, increased enzymatic activity, and an enhanced ability to degrade phenolic model lignin compounds. Transcriptomics analyses revealed that promethazine rapidly induced the expression of genes encoding lignin-degrading enzymes, including laccase and various oxidoreductases, showing that the increased laccase activity was due to increased laccase gene expression. Finally, the generality of promethazine as an inducer of laccases in fungi was demonstrated by showing that promethazine treatment also increased laccase activity in other relevant fungal species with known lignin conversion capabilities including Trametes versicolor and Pleurotus ostreatus.