Pycnoporus sanguineus Polysaccharides as Reducing Agents: Self-Assembled Composite Nanoparticles for Integrative Diabetic Wound Therapy

Purpose

Diabetic foot ulcers (DFU) are severe complications of diabetes, posing significant health and societal challenges. Elevated levels of reactive oxygen species (ROS) at the ulcer site hinder wound healing in most patients, while individuals with diabetes are also more susceptible to bacterial infections. This study aims to synthesize a comprehensive therapeutic material using polysaccharides from Pycnoporus sanguineus to promote DFU wound healing, reduce ROS levels, and minimize bacterial infections.

Methods

Polysaccharides from P.sanguineus were employed as reducing and stabilizing agents to fabricate polysaccharide-based composite particles (PCPs) utilizing silver ions as templates. PCPs were characterized via UV-Vis, TEM, FTIR, XRD, and DLS. The antioxidant, antimicrobial, and cytotoxic properties of PCPs were assessed through in vitro and cellular experiments. The effects and mechanisms of PCPs on wound healing were evaluated using a diabetic ulcer mouse model.

Results

PCPs exhibited spherical particles with an average size of 57.29±22.41 nm and effectively combined polysaccharides' antioxidant capacity with silver nanoparticles' antimicrobial function, showcasing synergistic therapeutic effects. In vitro and cellular experiments demonstrated that PCPs reduced cellular ROS levels by 54% at a concentration of 31.25 μg/mL and displayed potent antibacterial activity at 8 μg/mL. In vivo experiments revealed that PCPs enhanced the activities of superoxide dismutase (SOD) and catalase (CAT), promoting wound healing in DFUs and lowering the risk of bacterial infections.

Conclusion

The synthesized PCPs offer a novel strategy for the comprehensive treatment of DFU. By integrating antioxidant and antimicrobial functions, PCPs effectively promote wound healing and alleviate patient suffering. The present study demonstrates a new strategy for the integrated treatment of diabetic wounds and expands the way for developing and applying the polysaccharide properties of P. sanguineus.

Bioremediation of triphenyl phosphate by Pycnoporus sanguineus: Metabolic pathway, proteomic mechanism and biotoxicity assessment

So far, no information about the biodegradability of TPhP by white rot fungi has previously been made available, herein, Pycnoporus sanguineus was used as the representative to investigate the potential of white rot fungi in TPhP bioremediation. The results suggested that the biodegradation efficiency of 5 mg/L TPhP by P. sanguineus was 62.84% when pH was adjusted to 6 and initial glucose concentration was 5 g/L. Seven biodegradation products were identified, indicating that TPhP was biotransformed through oxidative cleavage, hydroxylation and methylation. The proteomic analysis revealed that cytochrome P450s, aromatic compound dioxygenase, oxidizing species-generating enzymes, methyltransferases and MFS general substrate transporters might occupy important roles in TPhP biotransformation. Carboxylesterase and glutathione S-transferase were induced to resist TPhP stress. The biotreatment by P. sanguineus contributed to a remarkable decrease of TPhP biotoxicity. Bioaugmentation with P. sanguineus could efficiently promote TPhP biodegradation in the water-sediment system due to the cooperation between P. sanguineus and some putative indigenous degraders, including Sphingobium, Burkholderia, Mycobacterium and Methylobacterium. Overall, this study provided the first insights into the degradation pathway, mechanism and security risk assessment of TPhP biodegradation by P. sanguineus and verified the feasibility of utilizing this fungus for TPhP bioremediation applications.

Fungal Treatment for the Valorization of Technical Soda Lignin

Technical lignins produced as a by-product in biorefinery processes represent a potential source of renewable carbon. In consideration of the possibilities of the industrial transformation of this substrate into various valuable bio-based molecules, the biological deconstruction of a technical soda lignin by filamentous fungi was investigated. The ability of three basidiomycetes (Polyporus brumalis, Pycnoporus sanguineus and Leiotrametes menziesii) to modify this material, the resultant structural and chemical changes, and the secreted proteins during growth on this substrate were investigated. The three fungi could grow on the technical lignin alone, and the growth rate increased when the media were supplemented with glucose or maltose. The proteomic analysis of the culture supernatants after three days of growth revealed the secretion of numerous Carbohydrate-Active Enzymes (CAZymes). The secretomic profiles varied widely between the strains and the presence of technical lignin alone triggered the early secretion of many lignin-acting oxidoreductases. The secretomes were notably rich in glycoside hydrolases and H₂O₂-producing auxiliary activity enzymes with copper radical oxidases being induced on lignin for all strains. The lignin treatment by fungi modified both the soluble and insoluble lignin fractions. A significant decrease in the amount of soluble higher molar mass compounds was observed in the case of P. sanguineus. This strain was also responsible for the modification of the lower molar mass compounds of the lignin insoluble fraction and a 40% decrease in the thioacidolysis yield. The similarity in the activities of P. sanguineus and P. brumalis in modifying the functional groups of the technical lignin were observed, the results suggest that the lignin has undergone structural changes, or at least changes in its composition, and pave the route for the utilization of filamentous fungi to functionalize technical lignins and produce the enzymes of interest for biorefinery applications.

Lipid-lowering effect of Pinus sp. sawdust and Pycnoporus sanguineus mycelium in streptozotocin-induced diabetic rats

The purpose of this study was to investigate the effect of diet supplementations on biochemical, hematological, and redox metabolism parameters in streptozotocin-induced diabetic rats. Healthy male Wistar rats and streptozotocin-induced diabetic rats were provided diets supplemented with 20% of Pinus sp. sawdust or Pycnoporus sanguineus mycelium for 4 weeks. Diabetic rats treated with both Pinus sp. sawdust- and P. sanguineus mycelium-supplemented diets presented a significant decrease in non-HDL cholesterol of 38.43% and 33.53% and triglycerides of 70.03% and 69.81%, respectively, compared to diabetic control. As far as we know, this is the first report of a significant decrease in serum lipids attributed to these supplementations. Even though with the alterations in hematological and redox metabolism parameters related to these diet treatments, our data suggest that Pinus sp. sawdust and Pycnoporus sanguineus mycelium could be a useful a diet supplement to control diabetic dyslipidemia in animals. PRACTICAL APPLICATIONS: Pinus sp. sawdust is a residue from the wood industry that can be reused as a substrate to cultivate Pycnoporus sanguineus mycelium. Both species have specific and rich natural compounds. The results of the present study surprisingly showed that diets supplemented with the isolated substrate (Pinus sp. sawdust) and Pycnoporus sanguineus mycelium significantly decrease non-HDL cholesterol and triglycerides in induced diabetic animal model. These new natural approaches can be interesting to develop a nutraceutical to treat dyslipidemia.

Ethanol extract of Pycnoporus sanguineus relieves the dextran sulfate sodium-induced experimental colitis by suppressing helper T cell-mediated inflammation via apoptosis induction

Inflammatory bowel disease (IBD) is a chronic relapsing inflammation involving the gut system, and disequilibrium of T helper (Th) cell paradigm has been recognized as critical pathogenesis. Pycnoporus sanguineus (L.) Murrill is a species of the white-rot basidiomycetes listed as food- and cosmetic-grade microorganisms. In this study, anti-inflammatory activity of the ethanol extract from P. sanguineus (PSE) was investigated in dextran sulfate sodium (DSS)-induced experimental colitis model. PSE recovered the DSS-caused weight loss, reversed the colon shortening, and ameliorated the histopathological lesion in colon, resulting in lower disease activity index (DAI). Levels of serumal lipopolysaccharide (LPS), colonic myeloperoxidase (MPO) in the colitis-suffering mice were declined by PSE treatment. PSE also improved the mucosal integrity by enhancing the expression of tight junction and adherens junction proteins in the colon, including ZO-1, occludin, claudin-1, and E-cadherin. Besides, PSE reduced helper T cells (Th) in the colon, together with an evident decrease of several Th cell-related cytokines. Moreover, it was found that in vitro, PSE suppressed T cells and the Th subset upon Concanavalin A (ConA)-stimulation by inducing apoptosis. In summary, PSE displayed a remission on the colitis-related inflammation, which would possibly rely on the epithelial barrier restoration by suppressing Th cells via apoptosis induction, highlighting a promising potential in the treatment for IBD.

Polysaccharide from Pycnoporus sanguineus ameliorates dextran sulfate sodium-induced colitis via helper T cells repertoire modulation and autophagy suppression

Inflammatory bowel disease (IBD) is a chronic autoimmune disease associated with various risk factors. Pycnoporus sanguineus (L.) Murrill is a saprotrophic fungus used worldwide for its industrial and medical purposes. Here, polysaccharide from P. sanguineus (PPS) was explored for its antiinflammatory potential in a murine colitis model of IBD induced by dextran sulfate sodium (DSS). PPS ameliorated the colitis as manifested by the lowered disease activity index (DAI), prolonged colon, and reduced serum lipopolysaccharide (LPS). PPS recovered the histological lesion by upregulating the expressions of Zonula occludens-1 (ZO-1), E-cadherin, and proliferating cell nuclear antigen (PCNA). PPS inhibited the helper T cells (Th)-mediated immune response by decreasing the proportions of Th cells (including Th2 cells, Th17 cells, and regulatory T cells), which was accompanied with reductions on myeloperoxidase (MPO) activity and releases of several interleukins and chemokines within the colon. Moreover, PPS exhibited an evident inhibition on autophagy, in which the ratio of light chain 3 (LC3) II/I was declined, while the expression of p62 and Beclin-1 was increased. The present study highlighted important clinical implications for the treatment application of PPS against IBD, which relies on the regulation of Th cells repertoire and autophagy suppression to restore epithelium barrier.

Genome sequence of the fungus Pycnoporus sanguineus, which produces cinnabarinic acid and pH- and thermo- stable laccases

Pycnoporus sanguineus, an edible mushroom, produces antimicrobial and antitumor bioactive compounds and pH- and thermo- stable laccases that have multiple potential biotechnological applications. Here we reported the complete genome of the species Pycnoporus sanguineus ACCC 51,180 by using the combination of Illumina HiSeq X Ten and the PacBio sequencing technology. The represented genome is 36.6 Mb composed of 59 scaffolds with 12,086 functionally annotated protein-coding genes. The genome of Pycnoporus sanguineus encodes at least 19 biosynthetic gene clusters for secondary metabolites, including a terpene cluster for biosynthesis of the antitumor clavaric acid. Seven laccases were identified, while 22 genes were found to be involved in the kynurenine pathway in which the intermediate metabolite 3-hydroxyanthranilic acid were catalyzed by laccases into cinnabarinic acid. This study represented the third genome of the genus Pycnoporus, and wound facilitate the exploration of useful sources from Pycnoporus sanguineus for future industrial applications.

Allergic Bronchopulmonary Mycosis Caused by Schizophyllum commune: A Special Interest in Positive Culture of Other Basidiomycetes Fungi

A 42-year-old man with asthma presented in 2007 with chest infiltration and productive cough. Pycnoporus sanguineus and Perenniporia tephropora were repeatedly isolated from sputum and bronchial washing fluids. Because we lacked immunologic evidence, we could not diagnose him with allergic bronchopulmonary mycosis (ABPM) due to these basidiomycetous fungi. At that time, serum-specific IgE and IgG against Schizophyllum commune findings were negative. Inhaled beclomethasone/salmeterol improved his condition. Seven years later, mucous plugs obtained via bronchoscopy at a relapse were compatible with allergic mucin. Because S. commune was isolated from mucous plugs and serum-specific IgG against S. commune turned positive, we diagnosed the patient with ABPM due to S. commune.

Effect of hexavalent chromium on the biodegradation of tetrabromobisphenol A (TBBPA) by Pycnoporus sanguineus

The influence of Cr(VI) on the degradation of tetrabromobisphenol A (TBBPA) by a typical species of white rot fungi, Pycnoporus sanguineus, was investigated in this study. The results showed that P. sanguineus together with its intracellular and extracellular enzyme could effectively degrade TBBPA. The degradation efficiency of TBBPA by both P. sanguineus and its enzymes decreased significantly when Cr(VI) concentration increased from 0 to 40 mg/L. The subsequent analysis about cellular distribution of TBBPA showed that the extracellular amount of TBBPA increased with the increment of Cr(VI) concentration, but the content of TBBPA inside fungal cells exhibited an opposite variation tendency. The inhibition of TBBPA degradation by P. sanguineus was partly attributed to the increase of cell membrane permeability and the decrease of cell membrane fluidity caused by Cr(VI). In addition, the decline of H⁺-ATPase and Mg²⁺-ATPase activities was also an important factor contributing to the suppression of TBBPA degradation in the system containing concomitant Cr(VI). Moreover, the activities of two typical extracellular lignin-degrading enzymes of P. sanguineus, MnP and Lac, were found to descend with ascended Cr(VI) level. Cr(VI) could also obviously suppress the gene expression of four intracellular enzymes implicated in TBBPA degradation, including two cytochrome P450s, glutathione S-transferases and pentachlorophenol 4-monooxygenase, which resulted in a decline of TBBPA degradation efficiency by fungal cells and intracellular enzyme in the presence of Cr(VI). Overall, this study provides new insights into the characteristics and mechanisms involved in TBBPA biodegradation by white rot fungi in an environment where heavy metals co-exist.

Degradation of 2,2',4,4'-tetrabromodiphenyl ether by Pycnoporus sanguineus in the presence of copper ions

The degradation of 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) by Pycnoporus sanguineus was investigated in order to explore the impact of the heavy metal Cu²⁺ on BDE-47 decomposition and the subsequent formation of metabolites, as well as to further elucidate the degradation mechanism of BDE-47. An increase in degradation rate from 18.63% to 49.76% in the first four days and its stabilization at (51.26 ± 0.08)% in the following days of BDE-47 incubation were observed. The presence of Cu²⁺ at 1 and 2 mg/L was found to promote the degradation rate to 56.41% and 60.79%, respectively, whereas higher level of Cu²⁺ (≥5 mg/L) inhibited the removal of BDE-47. The similar concentration effects of Cu²⁺ was also found on contents of fungal protein and amounts of metabolites. Both intracellular and extracellular enzymes played certain roles in BDE-47 transportation with the best degradation rate at 27.90% and 27.67% on the fourth and third day, individually. During the degradation of BDE-47, four types of hydroxylated polybrominated diphenyl ethers (OH-PBDEs), i.e., 6'-OH-BDE-47, 5'-OH-BDE-47, 4'-OH-BDE-17, 2'-OH-BDE-28, and two bromophenols, i.e., 2,4-DBP and 4-BP were detected and considered as degradation products. These metabolites were further removed by P. sanguineus at rates of 22.42%, 23.01%, 27.04%, 27.96%, 64.21%, and 40.62%, respectively.

iTRAQ-based proteomic profiling of Pycnoporus sanguineus in response to co-existed tetrabromobisphenol A (TBBPA) and hexavalent chromium

In current study, we investigated the changes of proteome profiles of Pycnoporus sanguineus after a single exposure of Cr(VI), TBBPA and a combined exposure of TBBPA and Cr(VI), with the goal of illuminating the cellular mechanisms involved in the interactions of co-existed TBBPA and Cr(VI) with the cells of P. sanguineus at the protein level. The results revealed that some ATP-binding cassette (ABC) transporters were obviously induced by these pollutants to accelerate the transportation, transformation and detoxification of TBBPA and Cr(VI). Cr(VI) could inhibit the bioremoval of its organic co-pollutants TBBPA through suppressing the expression of several key proteins related to the metabolism of TBBPA by P. sanguineus, including two cytochrome P450s, pentachlorophenol 4-monooxygenase and glutathione S-transferases. Furthermore, Cr(VI) possibly reduced the cell vitality and growth of P. sanguineus by enhancing the expression of imidazole glycerol phosphate synthase as well as by decreasing the abundances of proteins associated with the intracellular metabolic processes, such as the tricarboxylic acid cycle, purine metabolism and glutathione biosynthesis, thereby adversely affecting the biotransformation of TBBPA. Cr(VI) also inhibited the expression of peptidyl prolyl cis/trans isomerases, thus causing the damage of cell membrane integrity. In addition, some important proteins participated in the resistance to Cr(VI) toxicity were observed to up-regulate, including heat shock proteins, 26S proteasome, peroxiredoxins and three critical proteins implicated in S-adenosyl methionine synthesis, which contributed to reducing the hazard of Cr(VI) to P. sanguineus. The results of this study provide novel insights into the physiological responses and molecular mechanism of white rot fungi P. sanguineus to the stress of concomitant TBBPA and Cr(VI).

Hexavalent chromium induced oxidative stress and apoptosis in Pycnoporus sanguineus

White rot fungi have been proved to be a promising option for the removal of heavy metals, understanding their toxic response to heavy metals is conducive to developing and popularizing fungi-based remediation technologies so as to lessen the hazard of heavy metals. In this study, Cr(VI)-induced oxidative stress and apoptosis in Pycnoporus sanguineus, a species of white rot fungi were investigated. The results suggested that high level of Cr(VI) promoted the formation of ROS, including H₂O₂, O₂^•- and ·OH. With the increment of Cr(VI) concentration, the SOD and CAT activity along with GSH content increased within the first 24 h, but decreased afterward, companied with a significant enhancement of MDA content. Cr(VI)-induced oxidative damage further caused and aggravated apoptosis in P. sanguineus, especially at Cr(VI) concentrations above 20 mg/L. Cr(VI)-induced apoptosis was involved with mitochondrial dysfunction including mitochondrial depolarization, the enhancement of mitochondrial permeability and release of cytochrome c. The early and late apoptosis hallmarks, such as metacaspase activation, phosphatidylserine (PS) externalization, DNA fragmentation and the nuclear condensation and fragmentation were observed. Moreover, we also found disturbances of ion homeostasis, which was featured by K⁺ effluxes and overload of cytoplasmic and mitochondrial Ca²⁺.Based on these results, we suggest that Cr(VI) induced oxidative stress and apoptosis in white rot fungi, P. sanguineus.

Influence of co-existed tetrabromobisphenol A (TBBPA) and hexavalent chromium on the cellular characteristics of Pycnoporus sanguineus during their removal and reduction

Simultaneous TBBPA removal and Cr(VI) reduction by Pycnoporus sanguineus together with the effect of these co-existed pollutants on the fungal cellular characteristics were investigated in this study, aiming at illuminating the mechanism involved in the interactions between contaminants and microbial cells. The results revealed that Cr(VI) reduction and TBBPA removal declined from 92.5%, 75.4-30.6%, 44.8% when Cr(VI) concentration increased from 5 to 40mg/L, respectively. The removal efficiencies for Cr(VI) and TBBPA reached 61.4% and 94% separately under the optimum concentration of TBBPA at 10mg/L. Subsequent analyses indicated that the negative effect of Cr(VI) of high concentrations on Cr(VI) reduction and TBBPA removal was mainly attributed to the inhibition of fungal growth, intracellular proteins synthesis, cell viability and ATP enzyme activity. Compared with the moderate impact of TBBPA, the cell membrane of P. sanguineus was impaired severely and the surface morphology and intracellular structure changed dramatically in the presence of high concentration of Cr(VI) (above 10mg/L). This study also suggested that high level of TBBPA (15 and 20mg/L) promoted the synthesis of intracellular proteins and improved ATP enzyme activity within the first 48h of the reaction for enhancing the transportation and transformation of TBBPA.

Eichhornia crassipes: Agro-waster for a novel thermostable laccase production by Pycnoporus sanguineus SYBC-L1

The aim of this study was to explore the utilization of an intractable waster of Eichhornia crassipes in laccase production by Pycnoporus sanguineus SYBC-L1. E. crassipes as the sole carbon and nitrogen source was confirmed to produce laccase (7.26 U/g dry substrate). The fermentation medium for the maximum enzyme production was optimized and the laccase was then purified and characterized. The optimized culture medium was 25.1% E. crassipes, 13.9% sawdust, 1.5 mM CuSO₄, 40 μM gallic acid, 65% moisture content and initial pH 6.0. A maximum laccase activity of 32.02 U/g dry substrate was detected at 9th day, which was 4.5-fold compared to the initial medium. The molecular mass of the purified Lac-S was 58.4 kDa. The optimum activity of Lac-S for DMP was at pH 3.0 and 70°C. Lac-S showed not only high catalytic activities at low temperature, but also good stabilities toward pH and temperature. The residual catalytic activities of Lac-S were 30%, 40% and 50% at 0°C, 10°C and 20°C, and the half-lives at 50°C, 60°C and 70°C were 21.7, 9.7 and 1.5 h, respectively. The results provide a significant basis for E. crassipes further utilization and Lac-S specific application in harsh industry.

Improving the bioremoval of sulfamethoxazole and alleviating cytotoxicity of its biotransformation by laccase producing system under coculture of Pycnoporus sanguineus and Alcaligenes faecalis

The occurrence of sulfamethoxazole (SMX) in aquatic environment is a health concern. The presence of SMX significantly inhibited the laccase activity of Pycnoporus sanguineus with a lower removal efficiency of SMX. Although a laccase system with 2,20-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) eliminated 100% SMX within 6h, ABTS might cause an environmental issue. An alternative to SMX elimination is the coculture of Alcaligenes faecalis and P. sanguineus. The SMX removal efficiency at 48h under the coculture with vitamins was higher than that under their pure culture alone, indicating that a coculture was more efficient in eliminating SMX than a pure culture. Only 1% SMX was detected in mycelia, indicating that SMX elimination is achieved primarily through biotransformation rather than adsorption. Laccase production by the coculture effectively inhibited the accumulations of N4-acetyl-SMX and N-hydroxy-SMX and alleviated the cytotoxicity of SMX transformation products. The mixture of SMX and sulfadiazine inhibited their removal efficiency.

A High Redox Potential Laccase from Pycnoporus sanguineus RP15: Potential Application for Dye Decolorization

Laccase production by Pycnoporus sanguineus RP15 grown in wheat bran and corncob under solid-state fermentation was optimized by response surface methodology using a Central Composite Rotational Design. A laccase (Lacps1) was purified and characterized and the potential of the pure Lacps1 and the crude culture extract for synthetic dye decolorization was evaluated. At optimal conditions (eight days, 26 °C, 18% (w/w) milled corncob, 0.8% (w/w) NH₄Cl and 50 mmol·L⁻¹ CuSO₄, initial moisture 4.1 mL·g⁻¹), the laccase activity reached 138.6 ± 13.2 U·g⁻¹. Lacps1 was a monomeric glycoprotein (67 kDa, 24% carbohydrate). Optimum pH and temperature for the oxidation of 2,2’-azino-bis(3-ethylbenzthiazoline-6-sulfonate) (ABTS) were 4.4 and 74.4 °C, respectively. Lacps1 was stable at pH 3.0–8.0, and after two hours at 55–60 °C, presenting high redox potential (0.747 V vs. NHE). ABTS was oxidized with an apparent affinity constant of 147.0 ± 6.4 μmol·L⁻¹, maximum velocity of 413.4 ± 21.2 U·mg⁻¹ and catalytic efficiency of 3140.1 ± 149.6 L·mmol⁻¹·s⁻¹. The maximum decolorization percentages of bromophenol blue (BPB), remazol brilliant blue R and reactive blue 4 (RB4), at 25 or 40 °C without redox mediators, reached 90%, 80% and 60%, respectively, using either pure Lacps1 or the crude extract. This is the first study of the decolorization of BPB and RB4 by a P. sanguineus laccase. The data suggested good potential for treatment of industrial dye-containing effluents.

Biosynthesis of gold nanoparticles assisted by the intracellular protein extract of Pycnoporus sanguineus and its catalysis in degradation of 4-nitroaniline

The development of green procedure for the synthesis of gold nanoparticles (AuNPs) has gained great interest in the field of nanotechnology. Biological synthetic routes are considered to be environmentally benign and cost-effective. In the present study, the feasibility of AuNPs' synthesis via intracellular protein extract (IPE) of Pycnoporus sanguineus was explored. The characteristics of generated particles of formation, crystalline nature, and morphology and dimension were analyzed by UV-vis spectroscopy, X-ray diffraction (XRD) and transmission electron microscopy (TEM), respectively. UV-vis spectra exhibited strong absorption peaks in 520 to 560 nm, indicating the formation of AuNPs. XRD analysis revealed that the formed AuNPs were purely crystalline in nature. TEM observation showed that AuNPs with various shapes including spherical, pseudo-spherical, triangular, truncated triangular, pentagonal, and hexagonal, ranging from several to several hundred nanometers, were synthesized under different conditions. The average size of AuNPs decreased from 61.47 to 29.30 nm as the IPE addition increased from 10 to 80 mL. When the initial gold ion concentration changed from 0.5 to 2.0 mM, the average size rose from 25.88 to 51.99 nm. As in the case of solution pH, the average size was 84.29 nm with solution pH of 2.0, which diminished to 6.07 nm with solution pH of 12.0. Fourier transform infrared (FTIR) analysis implied that the functional groups including hydroxyl, amine, and carboxyl were involved in the reduction of gold ions and stabilization of AuNPs. The catalysis results showed that 0.019 mg of AuNPs with average size of 6.07 nm could catalyze the complete degradation of 12.5 μmol of 4-nitroaniline within 6 min and the degradation rate increased drastically with the addition of AuNPs. All the results suggested that the IPE of P. sanguineus could be potentially applied for the eco-friendly synthesis of AuNPs.

Biotransformation of Endocrine-Disrupting Compounds in Groundwater: Bisphenol A, Nonylphenol, Ethynylestradiol and Triclosan by a Laccase Cocktail from Pycnoporus sanguineus CS43

The biodegradation of organic compounds present in water at trace concentration has become a critical environmental problem. In particular, enzymatic oxidation by fungal laccases offers a promising alternative for efficient and sustainable removal of organic pollutants in water. In this work, the biocatalytic ability of laccases from the Pycnoporus sanguineus CS43 fungus was evaluated. A filtered culture supernatant (laccase cocktail) evidenced an enhanced biotransformation capability to remove common endocrine-disruptor compounds (EDCs), such as bisphenol A, 4-nonylphenol, 17-α-ethynylestradiol and triclosan. A biodegradation of around 89-100 % was achieved for all EDCs using synthetic samples (10 mg L^-1) and after the enzymatic treatment with 100 U L^-1 (50.3 U mg ^-1). The biodegradation rates obtained were fitted to a first order reaction. Furthermore, enzymatic biocatalytic activity was also evaluated in groundwater samples coming from northwestern Mexico, reaching biotransformation percentages between 55 and 93 % for all tested compounds. As far as we know this is the first study on real groundwater samples in which the enzymatic degradation of target EDCs by a laccase cocktail from any strain of Pycnoporus sanguineus was evaluated. In comparison with purified laccases, the use of cocktail offers operational advantages since additional purification steps can be avoided.

Production and characterization of tyrosinase activity in Pycnoporus sanguineus CCT-4518 Crude extract

Tyrosinase is an enzyme of industrial interest. The production and characterization of tyrosinase from P. sanguineus CCT-4518 were investigated. The selection of inductors, luminosity influence, inoculum size and type of culture medium on the production of tyrosinase and the effect of inhibitors on enzyme activity were performed. Optimum conditions for intracellular tyrosinase production was observed after 2 days using 0.15% L-tyrosine as inducer, in the presence of light, with inoculum size of 10 mycelium discs, using 2% malt extract broth medium, incubated at 30°C, and constant agitation of 150 rpm. Tyrosinase activity was completely inhibited by the addition of 6 mM salicylhydroxamic acid or phenylthiourea, however an inhibition of 4.15% was recorded by the addition of 0.1 mM sodium azide. No inhibition could be detected in case of 0.1 mM phenyl methanesulfonyl fluoride addition. Optimal conditions for intracellular tyrosinase activity using L-dopa as substrate were observed at pH 6.6 and 45°C. Thermal stability studies indicated that the enzyme is stable at 45°C for 15 minutes. Higher temperatures decreased tyrosinase activity. Enzyme production was confirmed by non-denaturing polyacrylamide gel electrophoresis and the protein profile was investigated by denaturing polyacrylamide gel electrophoresis.

Production of laccase by Pynoporus sanguineus using 2,5 - Xylidine and ethanol

Enzyme application in biotechnological and environmental processes has had increasing interest due to its efficiency, selectivity and mainly for being environmentally healthful, but these applications require a great volume of enzymes. In this work the effect of different concentrations of ethanol and 2,5-xylidine on growth and production of laccase by Pycnoporus sanguineus was investigated. In a medium containing 200 mg.L(-1) of 2,5-xylidine or 50 g.L(-1) of ethanol, the maximum activity of laccase was 2019 U.L(-1) and 1035 U.L(-1), respectively. No direct correlation between biomass and activity of laccase was observed for any of the inducers used during the tests. Ethanol concentrations, larger than or equal to 20 g.L(-1), inhibited the radial growth of P. sanguineus. This study showed that ethanol, which has less toxicity and cost than the majority of the studied inducers, presents promising perspectives for laccase production by P. sanguineus.