Phanerochaete Research Articles

Selective Adsorption of Lignin Peroxidase on Lignin for Biocatalytic Conversion of Poplar Wood Biomass to Value-Added Chemicals.

Lignin-first biorefineries aim to maximize the valorization of lignin by prioritizing its conversion over other biomass components. This study investigates the selective adsorption of lignin peroxidase (LiP) isozymes from white rot fungi Phanerochaete chrysosporium on lignin, aiming to enhance the biocatalytic conversion of poplar wood biomass into value-added chemicals. The research focuses on the adsorption characteristics of ten recombinant LiP isozymes, particularly PcLiP03, which exhibited the highest adsorption capacity on lignin and negligible adsorption on cellulose. Adsorption isotherms and structural analyses revealed that hydrophobic interactions significantly contribute to the selective adsorption of PcLiP03. Applying PcLiP03 in a continuous stirring cell system effectively converted lignin in unpretreated poplar wood to 2,6-dimethoxy-1,4-benzoquinone under ambient and mild conditions, highlighting its potential for selective lignin depolymerization in integrated biorefineries. This work underscores the importance of enzyme-substrate interactions and offers a promising approach for more efficient and sustainable biomass utilization.

Mutational analysis of Phanerochaete chrysosporium´s purine transporter.

We present here a mutational analysis of the purine transporter from Phanerochaete chrysosporium (PhZ), a member of the AzgA-like subfamily within the Nucleobase Ascorbate Transporters family. We identified key residues that determine its substrate specificity and transport efficiency. Thirteen PhZ mutants were generated and heterologously expressed in Aspergillus nidulans. The growth of mutant strains in the presence of purines and toxic analogues and the uptake rate of radiolabelled hypoxanthine were evaluated. Results revealed that ten mutants showed differences in transport compared to the wild-type PhZ: six mutants completely lost function, two exhibited decreased transport activity, and two showed increased hypoxanthine uptake. Subcellular localization and expression level analyses indicated that the differences in transport activity were not due to trafficking issues to the plasma membrane or protein stability. A three-dimensional model of PhZ, constructed with the artificial intelligence-based AlphaFold2 program, suggested that critical residues for transport are located in transmembrane segments and an internal helix. In the latter, the A418 residue was identified as playing a pivotal role in transport efficiency despite being far from the putative substrate binding site, as mutant A418V showed an increased initial uptake efficiency for the transporter´s physiological substrates. We also report that residue L124, which lies in the putative substrate binding site, plays a critical role in substrate transport, emerging as an additional determinant in the transport mechanism of this family of transporters. These findings underscore the importance of specific residues in AzgA-like transporters and enhance our understanding of the intricate mechanisms governing substrate specificity and transport efficiency within this family.

White rot fungi to decompose organophosphorus insecticides and their relation to soil microbial load and ligninolytic enzymes

The functional and structural features of microbial load in soil are influenced by the presence of insecticides. This study examined the impact of two organophosphorus insecticides, dimethoate and parathion on the microbial load of soil. The colony count of fungi, actinomycetes, bacteria, and nitrogen fixing bacteria was reduced after insecticides application at 7 and 14 days, but at 28 days the colony count began to increase. The growth of two white rot fungi including Pleurotus sajor-caju and Phanerochaete chrysosporium was affected by parathion, which was reflected by a decrease in colony radius to 1.85±0.05 and 0.75±0.06 cm, respectively, and by dimethoate, reflected by a decrease in colony radius to 3.33±0.12 and 1.85±0.05 cm, respectively at 40 mg/L compared to colony radius at control 7.90±0.12 and 7.50±0.06 cm, respectively. The applied low concentration (10 mg/L) encouraged P. sajor-caju and P. chrysosporium to remove up to 87.7% and 81.8% of dimethoate, respectively, and 69.20 and 68.30% of parathion, respectively compared with the decomposition at high dose (40 mg/L) at 28 days. The presence of insecticides induced the production of ligninolytic enzymes lignin peroxidase, laccase, and manganase peroxidase.

Efficacy of white rot fungal biomass of Phanerochaete chrysosporium for adsorption and removal of reactive red and reactive blue dyes from water

Water pollution has become a worldwide issue, particularly in developing countries. This study aimed to cleanse water contaminated with reactive red (RR-198) and reactive blue (RB-19) dyes via adsorption onto nonliving white rot fungal biomass Phanerochaete chrysosporium under different operational conditions. It was found that P. chrysosporium removed more of RB-19 than RB-198. The conditions of pH 3, temperature 50 °C, adsorbent dosage 0.6 g, particle sizes of adsorbent (0.25 mm), and contact time (30 min) were optimum for removal of the dyes. RR-198 and RB-19 were removed with levels of 78.4% and 86.4%, respectively at pH 3; 79.6% and 90.0%, respectively using 0.6 g of adsorbent dosage; 82.0% and 87.0%, respectively at 30 min; and 82.0% and 87.2%, respectively at 50 °C. Thus, dead P. chrysosporium biomass was shown to be a biosorbent for the uptake of RB-19 and RR-198 dyes.

Improving Hydrolytic Activity and Enantioselectivity of Epoxide Hydrolase from Phanerochaete chrysosporium by Directed Evolution.

Epoxide hydrolases (EHs) catalyze the conversion of epoxides into vicinal diols. The epoxide hydrolase gene from P. chrysosporium was previously cloned and subjected to site-directed mutation to study its enzyme activity, but the results were unsatisfactory. This study used error prone PCR and DNA shuffling to construct a PchEHA mutation library. We performed mutation-site combinations on PchEHA based on enzyme activity measurement results combined with directed evolution technology. More than 15,000 mutants were randomly selected for the preliminary screening of PchEHA enzyme activity alongside 38 mutant strains with increased enzyme activity or enantioselectivity. Protein expression and purification were conducted to determine the hydrolytic activity of PchEHA, and three mutants increased their activity by more than 95% compared with that of the wt. After multiple rounds of screening and site-specific mutagenesis, we found that F3 offers the best enzyme activity and enantioselectivity; furthermore, the molecular docking results confirmed this result. Overall, this study uncovered novel mutants with potential value as industrial biocatalysts.

Deciphering the biodegradation of thiamethoxam by Phanerochaete chrysosporium with natural siderite: Synergistic mechanisms, transcriptomics characterization, and molecular simulation

Fungi play vital roles in the fate of organic pollutants, particularly when interacting with minerals in aquatic and soil environments. Mechanisms by which fungi may mitigate pollutions in fungus-mineral interactions are still unclear. Inspired by biogeochemical cycling, we constructed a range of co-culture systems to investigate synergistic effects of the white-rot fungus Phanerochaete chrysosporium and the iron-bearing mineral siderite on thiamethoxam (THX) transformation, a common neonicotinoid pesticide. Co-culturing with siderite significantly enhanced THX transformation during the initial 10 days with a dose effect, achieving 86 % removal within 25 days. Fungi could affect siderite’s dissolution, transformation, and precipitation through their biological activities. These interactions triggered physiological adaptation and resilience in fungi. Siderite could enhance the activity of fungal ligninolytic enzymes and cytochrome P450, facilitating biotransformation. Genes expression related to growth, energy metabolism, and oxidative stress response upregulated, enhancing fungal resilience to THX. The primary THX degradation pathways included nitro-reduction, C-N cleavage, and de-chlorination. Molecular dynamics simulations provided insights into catalytic mechanisms of enzyme-THX interactions. Together, siderite could act as natural enhancers that endowed fungi to resist physical and chemical stresses in environments, providing insights into contaminants attenuation, fungal biomineralization, and the coevolution of the Earth's lithosphere and biosphere.

Role of white rot fungi in sustainable remediation of heavy metals from the contaminated environment

ABSTRACT Heavy metal contamination has severe impacts on the natural environment. The currently existing physico-chemical methods have certain limitations, restricting their wide-scale application. The use of biological agents like bacteria, algae, and fungi can help eliminate heavy metals without adversely affecting flora and fauna. Due to their inherent ability to withstand adverse environmental conditions, nowadays, mycoremediation approaches are receiving considerable attention for heavy metal removal from contaminated sites. In this review, we emphasised the role of white rot fungi in remediation of heavy metal along with different factors influencing biosorption, effects on exposed fungi, and the mechanisms involved. Bibliometric analysis tools have been applied to literature search and trend analysis of the research on white rot fungi-mediated heavy metal removal. Annual growth rates and average citations per document are 5.08% and 35.48, respectively. Phanerochaete chrysosporium, Pleurotus ostreatus, and Trametes versicolor have been widely explored for the remediation of heavy metals. In addition to providing some prospects, the review also highlighted a few limitations, including inconsistent removal and effects of environmental factors influencing the functioning of white rot fungi. Overall, white rot fungi have been found to have immense potential to be widely utilised for sustainable remediation of heavy metal-contaminated environments.

Exploring the Biocontrol Potential of Phanerochaete chrysosporium against Wheat Crown Rot.

The worldwide occurrence of wheat crown rot, predominantly caused by the pathogen Fusarium pseudograminearum, has a serious impact on wheat production. Numerous microorganisms have been employed as biocontrol agents, exhibiting effectiveness in addressing a wide array of plant pathogens through various pathways. The mycelium of the white-rot fungus Phanerochaete chrysosporium effectively inhibits the growth of F. pseudograminearum by tightly attaching to it and forming specialized penetrating structures. This process leads to the release of intracellular inclusions and the eventual disintegration of pathogen cells. Furthermore, volatile organic compounds and fermentation products produced by P. chrysosporium exhibit antifungal properties. A comprehensive understanding of the mechanisms and modalities of action will facilitate the advancement and implementation of this biocontrol fungus. In order to gain a deeper understanding of the mycoparasitic behavior of P. chrysosporium, transcriptome analyses were conducted to examine the interactions between P. chrysosporium and F. pseudograminearum at 36, 48, and 84 h. During mycoparasitism, the up-regulation of differentially expressed genes (DEGs) encoding fungal cell-wall-degrading enzymes (CWDEs), iron ion binding, and mycotoxins were mainly observed. Moreover, pot experiments revealed that P. chrysosporium not only promoted the growth and quality of wheat but also hindered the colonization of F. pseudograminearum in wheat seedlings. This led to a delay in the development of stem base rot, a reduction in disease severity and incidence, and the activation of the plant's self-defense mechanisms. Our study provides important insights into the biocontrol mechanisms employed by P. chrysosporium against wheat crown rot caused by F. pseudograminearum.

Toxicity and decomposition activity inhibition of VO2 micro/nanoparticles to white rot fungus Phanerochaete chrysosporium

Vanadium dioxide (VO2) is an excellent phase transition material widely used in various applications, and thus inevitably enters the environment via different routes and encounters various organisms. Nonetheless, limited information is available on the environmental hazards of VO2. In this study, we investigated the impact of two commercial VO2 particles, nanosized S-VO2 and micro-sized M-VO2 on the white rot fungus Phanerochaete chrysosporium. The growth of P. chrysosporium is significantly affected by VO2 particles, with S-VO2 displaying a higher inhibitory effect on weight gain. In addition, VO2 at high concentrations inhibits the formation of fungal fibrous hyphae and disrupts the integrity of fungus cells as evidenced by the cell membrane damage and the loss of cytoplasm. Notably, at 200 μg/mL, S-VO2 completely alters the morphology of P. chrysosporium, while the M-VO2 treatment does not affect the mycelium formation of P. chrysosporium. Additionally, VO2 particles inhibit the laccase activity secreted by P. chrysosporium, and thus prevent the dye decoloration and sawdust decomposition by P. chrysosporium. The mechanism underlying this toxicity is related to the dissolution of VO2 and the oxidative stress induced by VO2. Overall, our findings suggest that VO2 nanoparticles pose significant environmental hazards and risks to white rot fungi.

Enhancing the thermostability of lignin peroxidase: Heme as a keystone cofactor driving stability changes in heme enzymes

Heme-containing enzymes, critical across life's domains and promising for industrial use, face stability challenges. Despite the demand for robust industrial biocatalysts, the mechanisms underlying the thermal stability of heme enzymes remain poorly understood. Addressing this, our research utilizes a ‘keystone cofactor heme-interaction approach’ to enhance ligand binding and improve the stability of lignin peroxidase (LiP). We engineered mutants of the white-rot fungus PcLiP (Phanerochaete chrysosporium) to increase thermal stability by 8.66 °C and extend half-life by 29 times without losing catalytic efficiency at 60 °C, where typically, wild-type enzymes degrade. Molecular dynamics simulations reveal that an interlocked cofactor moiety contributes to enhanced structural stability in LiP variants. Additionally, a stability index developed from these simulations accurately predicts stabilizing mutations in other PcLiP isozymes. Using milled wood lignin, these mutants achieved triple the conversion yields at 40 °C compared to the wild type, offering insights for more sustainable white biotechnology through improved enzyme stability.

A novel fungal and bacterial consortium promotes the degradation of rice straw: Conditions optimization and degradation properties

The rapid development of agriculture has led to the production of a large amount of crop straw, necessitating effective strategies for its management. Microbial degradation offers a promising method. In this study, a novel microbial consortium composed of Phanerochaete chrysosporium, Aspergillus niger, and Streptomyces griseorubens, known for their robust lignocellulose degradation capabilities, was constructed for rice straw degradation. The establishment of this microbial consortium was based on the growth curve and antagonistic tests. Orthogonal optimization revealed that Streptomyces griseorubens played a predominant role in the degradation of rice straw. The optimal degradation conditions were determined as follows: nitrogen source concentration of 2.5 gL−1, material-liquid ratio of 40 g L−1, inoculum size of 3%, and pH value of 9. Under these conditions, the degradation efficiency reached 42% within 15 days. The decomposition of lignocellulosic components in the straw was confirmed through various characterization methods. Additionally, as the degradation process progressed, there was a noticeable decrease in protein-like substances and an increase in humic acid-like substances in the degradation solution.

Pretreatment and saccharification of corn cobs using partially purified fungal ligninozymes

AbstractCorn cobs consist primarily of a lignocellulosic material comprising hemicellulose, cellulose, and lignin in a crystalline state, which is resistant to microbial saccharification. Bioethanol production from corn cobs has rarely been attempted, especially using chemical pretreatment methods.The present study deals with the production and purification of fungal (Phanerochaete chrysosporium MTCC 787 and Pleurotus florida PAU 22‐01) extracellular ligninolytic enzymes – lignin peroxidase (LiP), manganese peroxidase (MnP), and laccase (Lac) – followed by their utilization for the biological pretreatment of corn cobs along with saccharification using commercial cellulase. Crude LiP, MnP, and Lac demonstrated specific activity of 2.23, 2.1, and 2.63 U/mg, respectively.The one‐step purification of crude enzyme using diethyl amino ethyl (DEAE) cellulose ion exchange chromatography resulted in 11.3, 10.1 and 8.62‐fold purification of LiP, MnP and Lac activity, respectively, with corresponding specific activity of 25.1 U/mg (LiP), 21.2 U/mg (MnP) and 22.7 U/mg (Lac) in the partially purified ligninozymes. Using the latter, biological pretreatment of 2.5 g corn cobs in a reaction volume of 30 mL containing approximately 200 units of Lac, Lip and MnP enzymes (in phosphate buffer, pH 6) resulted in a maximum of 78.4% delignification with a saccharification efficiency of 97.1% using commercial cellulases.

Investigating Degradation in Extrusion-Processed Bio-Based Composites Enhanced with Clay Nanofillers

This research investigates the extrusion-based fabrication and characterization of nanocomposites derived from bio-sourced polypropylene (PP) and poly(butylene succinate) (PBS: a biodegradable polymer derived from renewable biomass sources such as corn or sugarcane), incorporating Cloisite 20 (C20) clay nanofillers, with a specific focus on their suitability for electrical insulation applications. The research includes biodegradation tests employing the fungus Phanerochaete chrysosporium to evaluate the impact of composition and extrusion conditions. These tests yield satisfactory results, revealing a progressive disappearance of the PBS phase, as corroborated by scanning electron microscopy (SEM) observations and a reduction in the intensity of Fourier transform infrared spectroscopy (FTIR) peaks associated with C-OH and C-O-C bonds in PBS. Despite positive effects on various properties (i.e., barrier, thermal, electrical, and mechanical properties, etc.), a high clay content (5 wt%) does not seem to enhance biodegradability significantly, highlighting the specific sensitivity of the PBS phase to the addition of clay during this process. This study provides valuable insights into the complex interplay of factors conditioning nanocomposite biodegradation processes and highlights the need for an integrated approach to understanding these processes. This is the first time that research has focused on studying the degradation of nanocomposites for electrical insulation, utilizing partially bio-sourced materials that contain PBS.

Analysis of the stakes of the Xianyang Ancient Ferry Site, Shaanxi, China

Historical records indicate that Xianyang Ancient Ferry Site, dating back over three millennia to the late Shang Dynasty, has been an important transportation hub in ancient times. The use of combined wooden stakes and stones is a special method for flood control among ancient flood prevention techniques. This research aims to evaluate the current preservation condition of these ancient wooden stakes. The dating of the wooden stakes at the site ranges between 940 ± 30 BP and 320 ± 30 BP. The fiber cross-section and microstructure images of the wooden samples indicate that the wood is attributed to Platycladus orientalis. SEM images indicate decay and deterioration of the wooden samples, with the presence of mold spores within the cavities. XRD, FTIR, and TG/DSC spectra of historical wooden samples collected from the site and fresh Platycladus orientalis wood samples demonstrate a significant decrease of cellulose crystallinity in the historical samples, leading to severe deterioration of the wood at the site. Five dominant mold species were identified, i.e., Aspergillus niger, Aspergillus flavus, Penicillium citrinum, Trichoderma, and Phanerochaete chrysosporium, which accelerate the degradation of cellulose and other polysaccharides. This research provides scientific evidence for the selection of reinforcement materials and guides curators and conservators to formulate conservation strategies in the future.

1H, 13C and 15N backbone resonance assignment of Cel45A from Phanerochaete chrysosporium

A glycoside hydrolase family 45 (GH45) enzyme from the white-rot basidiomycete fungus Phanerochaete chrysosporium (PcCel45A) was expressed in Pichia pastoris with 13C and 15N labelling. A nearly complete assignment of 1H, 13C and 15N backbone resonances was obtained, as well as the secondary structure prediction based on the assigned chemical shifts using the TALOS-N software. The predicted secondary structure was almost identical to previously published crystal structures of the same enzyme, except for differences in the termini of the sequence. This is the first NMR study using an isotopically labelled GH45 enzyme.

PAHs Biodegradation by Locally Isolated Phanerochaete chrysosporium and Penicillium citrinum from Liquid and Spiked Soil

In the present study, biodegradation of polycyclic aromatic hydrocarbons (PAHs) was examined using two fungal strains, namely P. chrysosporium and P. citrinum, isolated from locally contaminated soil. These two fungal strains were compared based on degradation properties under standardized conditions (pH 7.0, temperature 30oC, carbon source yeast extract) using PAH sole and a mixture of five different PAHs. In liquid media, PAH degradation was higher as compared to spiked soil by P. chrysosporium, followed by P. citrinum. In liquid culture, maximum degradation was 96.13% phenanathrene, 86.34% fluoranthene, 72.75% pyrene, 52.25% chrysene, and 40.16% benzo(a)pyrene by P. chrysosporium. PAH degradation in spiked soil was 78.5% phenanthrene, 65.91% fluoranthene, 61.73% pyrene, 48.2% chrysene, and 26.82% benzo(a)pyrene within 28 days by P. chrysosporium. Both local fungal isolates showed potential for degradation of PAHs alone and in PAH mixtures.

Thermotolerance Mechanism of Fungal GH6 Cellobiohydrolase. Part II. Structural Analysis of Thermotolerant Mutant from the Basidiomycete Phanerochaete chrysosporium.

Glycoside hydrolase family 6 cellobiohydrolase (GH6 CBH) is a group of cellulases capable of hydrolyzing crystalline cellulose. However, the synergistic reaction of GH6 CBH with other cellulases is hindered by its relatively low thermotolerance. We previously obtained a thermotolerant double mutant, C240S/C393S, of GH6 CBH from the basidiomycete Phanerochaete chrysosporium (PcCel6A) by replacing the two free cysteine (Cys) residues, C240 and C393, with serine (Yamaguchi et al., J Appl Glycosci. 2020; 67;79-86). In the accompanying paper (Part I; Yamaguchi et al., J Appl Glycosci. 2024; 71: 55-62), we measured the temperature dependence of the activity and folding of C240S/C393S and its single mutants, C240S and C393S, and found that replacement of C393 was the major contributor to the increased thermotolerance of C240S/C393S. Here, in order to investigate the mechanism involved, we crystallized the wild-type and the mutant enzymes and compared their X-ray crystal structures. The overall structures of the wild-type and the three mutant enzymes were similar. However, C240S/C393S had the lowest relative B-factor at both the N-terminal loop (residues 172-177) and the C-terminal loop (residues 390-425). This result suggests that reduced structural fluctuation of the substrate-enclosing loops, possibly due to stronger hydrogen bonding involving C393, could account for the increased thermotolerance of C240S/C393S.

Thermotolerance Mechanism of Fungal GH6 Cellobiohydrolase. Part I. Characterization of Thermotolerant Mutant from the Basidiomycete Phanerochaete chrysosporium.

Cellobiohydrolase (CBH), belonging to glycoside hydrolase family 6 (GH6), plays an essential role in cellulose saccharification, but its low thermotolerance presents a challenge in improving the reaction efficiency. Based on a report that chimeric CBH II (GH6) engineered to remove non-disulfide-bonded free Cys shows increased thermotolerance, we previously mutated the two free Cys residues to Ser in GH6 CBH from the basidiomycete Phanerochaete chrysosporium (PcCel6A) and obtained a thermotolerant double mutant, C240S/C393S (Yamaguchi et al., J. Appl. Glycosci. 2020; 67: 79-86). Here, characterization of the double mutant revealed that its activity towards both amorphous and crystalline cellulose was higher than that of the wild-type enzyme at elevated temperature, suggesting that the catalytic domain is the major contributor to the increased thermotolerance. To investigate the role of each free Cys residue, we prepared both single mutants, C240S and C393S, of the catalytic domain of PcCel6A and examined their residual activity at high temperature and the temperature-dependent changes of folding by means of circular dichroism measurements and thermal shift assay. The results indicate that the C393S mutation is the main contributor to both the increased thermotolerance of C240S/C393S and the increased activity of the catalytic domain at high temperature.

Experimental study on the mechanism of coal spontaneous combustion inhibition by degradation of white-rot fungus

To investigate the mechanism of inhibition of spontaneous combustion of coal by degradation of white-rot fungus, the changes of macroscopic oxidizing characteristics and microstructure of the degraded coal were investigated by the programmed temperature-raising test and the in situ Fourier-transform infrared spectroscopy experiments. The difference in gas production between the degraded coal and the blank samples indicated that the degradation inhibited the oxidation process of coal, and the intensity of the inhibition effect was different at different oxidation stages. The strongest inhibition effect was found in the accelerated oxidation stage, i.e. 80–140 °C. To further analyze the micro-mechanism of the degradation of Phanerochaete chrysosporium affecting the spontaneous combustion of coal, the relative contents of active functional groups in coal samples were compared. The results showed that the degradation affected the relative contents of hydroxyl, aliphatic hydrocarbon, and oxygenated functional groups in coal. Among them, the most significant changes of –OH and –CO- were observed at 80–140 °C. Thus, it was analyzed that Phanerochaete chrysosporium could degrade the macromolecular structure of coal by generating biological enzymes to reduce the number of oxidizable functional groups such as –OH, –CH2, –CH3, –CO-, and so on, thus reducing the risk of spontaneous combustion of coal.

Valorizing fungal diversity for the degradation of fluoroquinolones

Continued widespread use of antibiotics, especially fluoroquinolones, raises environmental concerns, as its driving bacterial resistance and disrupts microbial ecosystems. Here we investigate the biodegradation of ten fluoroquinolone antibiotics (six for medical use and four for veterinary use) by ligninolytic fungi, including Trametes versicolor, Bjerkandera adusta, Porosterum spadiceum, Irpex lacteus, Pleuroteus ostreatus, Phanerochaete chrysosporium, Pycnoporus cinnabarinus, Ganoderma lucidum, and Gloeophyllum trabeum. The results show significant variations between strains in the efficiency of antibiotic transformation. B. adusta and P. spadiceum were the fungi that most efficiently reduced antibiotic concentrations and were able to totally degrade eight and six antibiotics, respectively, within a 15-day period. T. versicolor and P. ostreatus also showed the ability to effectively degrade antibiotics. Specifically, T. versicolor degraded six out of the ten fluoroquinolone antibiotics by more than 70 %, while P. ostreatus degraded the tested antibiotics between 43 % and 100 %. The remaining antibiotic activity did not always correlate with a reduction in antibiotic concentrations, which points to the presence of post-transformation antimicrobial metabolites. This study also explores the potential mechanisms used by these fungi to remove selected models of fluroquinolones via enzymatic routes, such as oxidation by laccases, heme-peroxidases, and cytochrome P450, or via adsorption on fungal biomass.