Search Results (59)

This work presents a new approach for lignocellulosic biomass pretreatment. The process is a sequential combination of extrusion (Ex) and semi-solid fermentation (SSF). To assess the Ex-SSF pretreatment efficiency, black spruce chips (wood residues) and corn stover (crop residues) were subjected to the process. The negative controls were the pretreatment of both residues with SSF alone without extrusion. Lignin peroxidase was the main ligninolytic enzyme contributing to the delignification in the negative controls. High lignin peroxide (LiP) activities were recorded for raw black spruce (53.7 ± 2.7 U/L) and corn stover (16.4 ± 0.8 U/L) compared to the Ex-SSF pretreated biomasses where the highest LiP activity recorded was 6.0 ± 0.3 U/L (corn residues). However, with the negative controls, only a maximum of 17% delignification was achieved for both biomasses. As for the Ex-SSF process, the pretreatments were preceded by the optimization of the extrusion (Ex) step and the semi-solid fermentation (SSF) step via experimental designs. The Ex-SSF pretreatments led to interesting results and offered cost-effective advantages compared to existing pretreatments. Biomass delignification reached 59.1% and 65.4% for black spruce and corn stover, respectively. For the analyses performed, it was found that manganese peroxidase (MnP) was the main contributor to delignification during the SSF step. MnP activity was up to 13.8 U/L for Ex-SSF pretreated black spruce, and 32.0 U/L for Ex-SSF pretreated corn stover, while the maximum MnP recorded in the negative controls was 1.4 ± 0.1 U/L. Ex-SSF pretreatment increased the cellulose crystallinity index (CrI) by 13% for black spruce and 4% for corn stover. But enzymatic digestibility of the Ex-SSF pretreated biomasses with 0.25 mL/g of enzyme led to 7.6 mg/L sugar recovery for black spruce, which is 2.3 times the raw biomass yield. The Ex-SSF pretreated corn stover led to 17.0 mg/L sugar recovery, which is a 44% improvement in sugar concentration compared to raw corn stover. However, increasing the enzyme content from 0.25 mL/g to 0.50 mg/L and 0.75 mg/L generated lower hydrolysis efficiency (the sugar recovery decreased). Full article

Persistent organohalogen pollutants—including halogenated nitrophenols (HNCs), trichloroethylene (TCE), and per- and polyfluoroalkyl substances (PFAS)—pose serious environmental and health risks due to their stability, toxicity, and bioaccumulation potential. This review critically assesses current remediation technologies including advanced oxidation processes (AOPs), adsorption, membrane filtration, and thermal treatments. While these methods can be effective, they are often limited by high costs, energy demands, toxic byproduct formation, and sustainability concerns. Emerging biological approaches offer promising alternatives. Among these, fungal-based degradation methods (mycodegradation) remain significantly underrepresented in the literature, despite fungi demonstrating a high tolerance to contaminants and the ability to degrade structurally complex compounds. Key findings reveal that white-rot fungi such as Phanerochaete chrysosporium and Trametes versicolor possess enzymatic systems capable of breaking down persistent organohalogens under conditions that inhibit bacterial activity. This review also identifies critical research gaps, including the need for direct comparative studies between fungal and bacterial systems. The findings suggest that integrating mycodegradation into broader treatment frameworks could enhance the environmental performance and reduce the long-term remediation costs. Overall, this review highlights the importance of diversifying remediation strategies to include scalable, low-impact biological methods for addressing the global challenge of organohalogen contamination. Full article

Biochemical monomer upcycling of plastic waste and its conversion into value-added products is deemed necessary, as it provides a greener and more sustainable solution to plastic waste management. In the current study, the polystyrene (PS) biodegradation potential of the fungus Phanerochaete chrysosporium NA3 was evaluated using various analytical techniques, such as Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), gel permeation chromatography (GPC), and high-performance liquid chromatography (HPLC). The biodegradation capacity of the fungal strain was further evaluated using a carbon dioxide (CO₂) evolution test, which showed that the PS films treated with NA3 produced more CO₂, indicating the strain’s ability to successfully utilize PS as a carbon source. The FTIR analysis of the PS films treated with NA3 showed modifications in the polymer chemical structure, including the formation of carbonyl and hydroxyl groups, which suggests the enzymatic dissociation of the polymer and the associated biodegradation mechanism. Pretreatments were found to be effective in modifying the polymer’s properties, making it more susceptible to microbial degradation, thus further accelerating the biodegradation process. The current study strongly advocates that P. chrysosporium (NA3) can be effectively used for the biochemical monomer recovery of PS waste and could be further utilized in the upcycling of plastic waste for its conversion into value-added products under the concept of circular economy. Full article

In the present work, brewer’s spent grain, BSG, the main by-product of beer production, was applied for the recovery of total polyphenols (TPs). Whole and ground BSG (wBSG and gBSG), derived from a Pilsen beer, was subjected to a solvent extraction using ethanol/water (50:50 v/v), and then, to improve TP recovery, microwave, ultrasound bath or probe pre-treatments were applied. The highest total phenolic content (TPC) (5.8 mg GAE/g_DW) was obtained with gBSG pre-treated with the ultrasound (US) probe for 15 min at 250 W. Solid-state fermentation (SSF) with Phanerochaete chrysosporium, in microcosms was investigated to improve the release of TPs. Microcosms were monitored by means of CO₂ production, the total proteins, and laccase activity. Fungal growth on gBSG, after only 10 days of fermentation, resulted in a 30% increase in the TPC compared to the unfermented substrate. Applying US probe-assisted extraction to fermented, ground BSG resulted in a 51% improvement compared to the untreated sample. Full article

This study focuses on the extraction of phenolic compounds from the fermentation of Phanerochaete chrysosporium and Gloeophyllum trabeum. The main goal was to synthesize phenol/chitosan microspheres and PVA films and characterized using FTIR, TGA, DSC, SEM, and mechanical tests to evaluate their physical, chemical, and mechanical properties for antimicrobial packaging applications. Homogeneous chitosan microspheres loaded with lignin-derived phenols were obtained, showing controlled release of antimicrobial compounds. The incorporation of phenolic microspheres into PVA/chitosan films resulted in significant improvements in mechanical properties: the films exhibited an elastic modulus of 36.14 ± 3.73 MPa, tensile strength of 12.01 ± 1.14 MPa, and elongation at break of 65.19 ± 5.96%. Thermal tests revealed that chitosan-containing films had enhanced thermal stability, with decomposition temperatures (T10) reaching 116.77 °C, compared to 89.28 °C for pure PVA. In terms of antimicrobial activity, PVA/chitosan/phenol films effectively reduced Lactobacillus growth and milk acidity, maintaining quality for up to 96 h at room temperature, outperforming controls with acetic acid and H₂O₂. The films also inhibit yeast growth for one week. In conclusion, phenols can be effective antimicrobial agents in dairy, but their use should be monitored. Additionally, PVA/chitosan-phenol films offer biodegradability, antimicrobial properties, and sustainability for diverse applications. Full article

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. Full article

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. Full article

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. Full article

The industrial sector plays a significant role in global economic growth. However, it also produces polluting effluents that must be treated to prevent environmental damage and ensure the quality of life for future generations is not compromised. Various physical, chemical, and biological methods have been employed to treat industrial effluents. Filamentous fungi, in particular, have garnered attention as effective bioremediation agents due to their ability to produce enzymes capable of degrading recalcitrant compounds, and adsorb different pollutant molecules. The novelty of the work reported herein lies in its comprehensive assessment of the research surrounding the use of white- and brown-rot fungi for removing phenolic compounds from industrial effluents. This study employs a systematic review coupled with scientometric analysis to provide insights into the evolution of this technology over time. It scrutinizes geographical distribution, identifies research gaps and trends, and highlights the most studied fungal species and their applications. A systematic review of 464 publications from 1945 to 2023 assessed the use of these fungi in removing phenolic compounds from industrial effluents. White-rot fungi were predominant (96.3%), notably Phanerochaete chrysosporium, Pleurotus ostreatus, Trametes versicolor, and Lentinula edodes. The cultures employing free cells (64.15%) stand out over those using immobilized cells, just like cultures with isolated fungi regarding systems with microbial consortia. Geographically, Italy, Spain, Greece, India, and Brazil emerged as the most prominent countries in publications related to this area during the evaluated period. Full article

In order to improve the performance of white rot fungi, especially the model species Phanerochaete chrysosporium in tetrabromobisphenol A (TBBPA) degradation, the strategy of synergizing Phanerochaete chrysosporium with nano iron oxides was considered; however, the effects of different nano iron oxides on Phanerochaete chrysosporium are still unknown. In this study, 20 nm γ-Fe₂O₃, 30 nm α-Fe₂O₃, 20 nm Fe₃O₄, and 200 nm Fe₃O₄ were used, and the fungal growth, oxidative stress, and ability to degrade TBBPA were monitored. The results showed that the addition of four nano iron oxides did not inhibit the growth of Phanerochaete chrysosporium. The effective antioxidant defense system of Phanerochaete chrysosporium could cope with almost all oxidative pressure induced by 200 nm Fe₃O₄. But when the size of nano iron oxide became significantly smaller or when the type of iron oxide changed from Fe₃O₄ to Fe₂O₃, a higher intracellular hydrogen peroxide (H₂O₂) content, lower intracellular superoxide dismutase (SOD) and catalase (CAT) activities and higher extracellular lactate dehydrogenase (LDH) activity were induced. When nano iron oxides synergized with Phanerochaete chrysosporium, the removal of TBBPA in all groups was slightly improved and mostly due to the degradation of TBBPA, with smaller iron oxides showing more enhancement for the degradation of TBBPA, while 200 nm Fe₃O₄ only enhanced the adsorption of TBBPA. The enhanced degradation of TBBPA showed no significant correlation with lignin-degrading enzyme activities but was closely correlated with the intracellular H₂O₂ concentration. Full article

This study assesses the efficacy of three white-rot fungi—Bjerkandera adusta, Phanerochaete chrysosporium, and Trametes versicolor—in degrading synthetic dyes and lignin in pulp and paper mill effluents, which annually contribute around 40,000 million cubic meters of dyed waste. Exploiting the structural resemblance of dyes to lignin, the fungi utilize ligninolytic enzymes—lignin peroxidase, manganese peroxidase, and laccase—to break down the pollutants. Initial mycoremediation trials in synthetic dye solutions with Direct black 80, Direct yellow 11, Basic brown 1, Orange II, and Red 8 BLP achieved decolorization rates of 70–80% within 7 days, except for Red 8 BLP. Both soluble and insoluble lignin fractions were significantly reduced, with an overall removal rate of 80–90%. Contrary to prior beliefs about the recalcitrance of azo dyes, B. adusta demonstrated substantial biodegradation capabilities, even on non-lignocellulosic substrates, such as dairy waste. The decolorization efficacy varied with dye structure, suggesting that efficiency should not be judged solely on color reduction. Remarkably, B. adusta also effectively decolorized and removed lignin from actual mill effluents without pH alteration, indicating a viable low-cost bioremediation strategy. This invites further investigation into optimizing B. adusta for industrial wastewater biodecolorization, especially in the field of PAHs (Polycyclic Aromatic Hydrocarbons) and EDCs (Endocrine Disrupting Chemicals). Full article

The conversion of lignocellulosic biomass to second-generation biofuels through enzymes is achieved at a high cost. Filamentous fungi through a combination of oxidative enzymes can easily disintegrate the glycosidic bonds of cellulose. The combination of cellobiose dehydrogenase (CDH) with lytic polysaccharide monooxygenases (LPMOs) enhances cellulose degradation in many folds. CDH increases cellulose deconstruction via coupling the oxidation of cellobiose to the reductive activation of LPMOs by catalyzing the addition of oxygen to C-H bonds of the glycosidic linkages. Fungal LPMOs show different regio-selectivity (C1 or C4) and result in oxidized products through modifications at reducing as well as nonreducing ends of the respective glucan chain. T. reesei LPMOs have shown great potential for oxidative cleavage of cellobiose at C1 and C4 glucan bonds, therefore, the incorporation of heterologous CDH further increases its potential for biofuel production for industrial purposes at a reduced cost. We introduced CDH of Phanerochaete chrysosporium (PcCDH) in Trichoderma reesei (which originally lacked CDH). We purified CDH through affinity chromatography and analyzed its enzymatic activity, electron-donating ability to LPMO, and the synergistic effect of LPMO and CDH on cellulose deconstruction. The optimum temperature of the recombinant PcCDH was found to be 45 °C and the optimum pH of PcCDH was observed as 4.5. PcCDH has high cello-oligosaccharide k_cat, K_m, and k_cat/K_m values. The synergistic effect of LPMO and cellulase significantly improved the degradation efficiency of phosphoric acid swollen cellulose (PASC) when CDH was used as the electron donor. We also found that LPMO undergoes auto-oxidative inactivation, and when PcCDH is used an electron donor has the function of a C1-type LPMO electron donor without additional substrate increments. This work provides novel insights into finding stable electron donors for LPMOs and paves the way forward in discovering efficient CDHs for enhanced cellulose degradation. Full article

The significant neutralization of waste streams required after the acidic bio-oxidation of sulfidic gold ores could be avoided by performing a novel treatment at circumneutral pH with an in situ neutralization. For the first time, the white-rot fungus Phanerochaete chrysosporium was incubated in a modified culture medium containing corn steep, an industrial waste product, to support microbial activity and, subsequently, the oxidation of a sulfidic ore at an initial circumneutral pH environment. In this investigation, the concentration of the native culture medium ingredients was first evaluated with response surface methodology to attain maximum sulfide oxidation. The statistical analysis proposed a modified culture medium composed of 12.86 g/L glucose, 2.20 g/L malt extract, 1.67 g/L yeast extract, and 0.49 g/L MgSO₄·7H₂O to reach a maximum of 28.7% sulfide oxidation after 14 d-bio-oxidation. pH-controlled batch cultures showed that an increase in initial pH in the range of 5.8 to 7.0 reduced the microbial activity, affecting sulfide oxidation. In addition, the modified culture medium at which yeast extract was substituted with 1.67 g/L corn steep produced comparable microbial activity and sulfide oxidation after 14 d, attaining 21.6% at 5% w/v with a maximum 39 U/L lignin peroxidase and 116 U/L manganese peroxidase. A 40.6% sulfide oxidation and 43.8% gold recovery were obtained after 42 d three-cycle replenishing bio-oxidation and 24 h cyanidation, respectively. Overall, corn steep waste showed the potential to substitute more expensive culture medium ingredients, supporting microbial activity and oxidation of sulfidic gold ores at an initial circumneutral pH and contributing to circularity of waste management. Full article

Polycyclic aromatic hydrocarbons (PAHs) are persistent environmental pollutants that pose a threat to human health. Among these PAHs, benzo[a]pyrene (BaP), a five-ring compound, exhibits high resistance to biodegradation. White-rot fungus Phlebia acerina S-LWZ20190614-6 has demonstrated higher BaP degradation capabilities compared with Phanerochaete chrysosporium and P. sordida YK-624, achieving a degradation rate of 57.7% after 32 days of incubation under a ligninolytic condition. To further enhance the biodegradation rate, three nonionic surfactants were used, and the addition of 1 or 2 g·L⁻¹ of polyethylene glycol monododecyl ether (Brij 30) resulted in nearly complete BaP biodegradation by P. acerina S-LWZ20190614-6. Interestingly, Brij 30 did not significantly affect the activity of manganese peroxidase and lignin peroxidase, but it did decrease laccase activity. Furthermore, the impact of cytochrome P450 on BaP degradation by P. acerina S-LWZ20190614-6 was found to be relatively mild. Transcriptomic analysis provided insights into the degradation mechanism of BaP, revealing the involvement of genes related to energy production and the synthesis of active enzymes crucial for BaP degradation. The addition of Brij 30 significantly upregulated various transferase and binding protein genes in P. acerina S-LWZ20190614-6. Hence, the bioremediation potential of BaP by the white-rot fungus P. acerina S-LWZ20190614-6 holds promise and warrants further exploration. Full article