Chrysosporium Strain Research Articles

Morphological and phylogenetic characterisations reveal nine new species of Chrysosporium (Onygenaceae, Onygenales) in China

Twenty-three strains of Chrysosporium were isolated from soil samples in different provinces of China. Phylogenetic analyses of ITS sequence data showed that these strains comprised nine new species and four already known species. The new species could be also distinguished from related species by their morphology. The results of phylogenetic and morphological analyses confirmed the nine new species of Chrysosporium. Descriptions and illustrations of these new species are provided.

The effect of microorganisms on the biomodification of montan resin from lignite

Montan resin (MR) is an industrial by-product or solid waste generated during the production of refined montan wax and is not typically reused. In this paper, a bio-modification method using three strains of microorganisms, Acinetobacter venetianus (AV), Pseudomonas aeruginosa (PA), and Phanerochaete chrysosporium (PC), was studied to promote the performance and bio-function of MR so that MR could be recycled. MR can be degraded by these three microorganisms, and their weight loss rates were similar over the treatment period of 15 days. Compared with the original MR, the hydrophilicity of modified MRs was improved, which was related to the increase in apparent oil-water partition coefficients (Kows) and oxygen-containing and hydrophilic groups in modified MRs based on IR and GC-MS analysis. The bio-function of modified MRs by the three strains in terms of promoting maize seed germination and seedling growth was greater compared with untreated MR. Overall, these findings indicate that biomodified MRs might have useful agriculture applications.

Decolorization and detoxification of different azo dyes by Phanerochaete chrysosporium ME-446 under submerged fermentation.

Azo dyes are widely used in the textile industry due to their resistance to light, moisture, and oxidants. They are also an important class of environmental contaminant because of the amount of dye that reaches natural water resources and because they can be toxic, mutagenic, and carcinogenic. Different technologies are used for the decolorization of wastewater containing dyes; among them, the biological processes are the most promising environmentally. The aim of this study was to evaluate the potential of Phanerochaete chrysosporium strain ME-446 to safely decolorize three azo dyes: Direct Yellow 27 (DY27), Reactive Black 5 (RB5), and Reactive Red 120 (RR120). Decolorization efficiency was determined by ultraviolet-visible spectrophotometry and the phytotoxicity of the solutions before and after the fungal treatment was analyzed using Lactuca sativa seeds. P. chrysosporium ME-446 was highly efficient in decolorizing DY27, RB5, and RR120 at 50 mg L-1, decreasing their colors by 82%, 89%, and 94% within 10 days. Removal of dyes was achieved through adsorption on the fungal mycelium as well as biodegradation, inferred by the changes in the dyes' spectral peaks. The intensive decolorization of DY27 and RB5 corresponded to a decrease in phytotoxicity. However, phytotoxicity increased during the removal of color for the dye RR120. The ecotoxicity tests showed that the absence of color does not necessarily translate to an absence of toxicity.

Phanerochaete chrysosporiumstrain B-22, a nematophagous fungus parasitizing Meloidogyne incognita.

The root-knot nematode Meloidogyne incognita has a wide host range and it is one of the most economically important crop parasites worldwide. Biological control has been a good approach for reducing M. incognita infection, for which many nematophagous fungi are reportedly applicable. However, the controlling effects of Phanerochaete chrysosporium strain B-22 are still unclear. In the present study we characterized the parasitism of this strain on M. incognita eggs, second-stage juveniles (J2), and adult females. The highest corrected mortality was 71.9% at 3 × 108 colony forming units (CFU) mL-1 and the estimated median lethal concentration of the fungus was 0.96 × 108 CFU mL-1. Two days after treatment with Phanerochaete chrysosporium strain B-22 eggshells were dissolved. A strong lethal effect was noted against J2, as the fungal spores developed in their body walls, germinated, and the resulting hyphae crossed the juvenile cuticle to dissolve it, thereby causing shrinkage and deformation of the juvenile body wall. The spores and hyphae also attacked adult females, causing the shrinkage and dissolution of their bodies and leakage of contents after five days. Greenhouse experiments revealed that different concentrations of the fungal spores effectively controlled M. incognita. In the roots, the highest inhibition rate for adult females, juveniles, egg mass, and gall index was 84.61%, 78.91%, 84.25%, and 79.48%, respectively. The highest juvenile inhibition rate was 89.18% in the soil. Phanerochaete chrysosporium strain B-22 also improved tomato plant growth, therefore being safe for tomato plants while effectively parasitizing M. incognita. This strain is thus a promising biocontrol agent against M. incognita.

Kinetic studies of Bisphenol A in aqueous solutions by enzymatic treatment

Bisphenol A (BPA), which is a major component in the production of various consumer products, is one of the most significant endocrine-disrupting chemicals. In this research, the biocatalytic elimination of Bisphenol A using laccase produced by Phanerochaete chrysosporium was examined and optimized. The response surface methodology was used to study the effect of independent variables such as pH, temperature, initial laccase activity, initial Bisphenol A concentration, and the interactive effects of each variable on the removal of Bisphenol A and residual enzyme activity. Based on response surface plots, the maximum Bisphenol A removal (93%) was detected at a pH value of 8, temperature 40 °C, initial laccase concentration 3 U/ml, and initial Bisphenol A concentration 2 mM after 3 h of treatment. The results showed that pH and temperature are the primary determining factors in Bisphenol A elimination. Maximum reaction rate and Michaelis constant were calculated from the Lineweaver–Burk plots and are 20.12 µM−1 min and 820 µM, respectively. The linearity of the data on the Lineweaver–Burk plot and the excellent correlation coefficient imply that laccase has a propensity to pursue Michaelis–Menten kinetics. In the present study, a high Bisphenol A degradation velocity with a low Km value was attained using the enzyme produced by P. chrysosporium. The degradation of Bisphenol A by the crude extract of laccase using the P. chrysosporium strain would provide a cost effective solution and seems to be an attractive option for the removal of micropollutants, including the recognized and suspected endocrine disruptors.

High-yield production of manganese peroxidase, lignin peroxidase, and versatile peroxidase in Phanerochaete chrysosporium.

The white-rot fungus Phanerochaete chrysosporium secretes extracellular oxidative enzymes during secondary metabolism, but lacks versatile peroxidase, an enzyme important in ligninolysis and diverse biotechnology processes. In this study, we report the genetic modification of a P. chrysosporium strain capable of co-expressing two endogenous genes constitutively, manganese peroxidase (mnp1) and lignin peroxidase (lipH8), and the codon-optimized vpl2 gene from Pleurotus eryngii. For this purpose, we employed a highly efficient transformation method based on the use of shock waves developed by our group. The expression of recombinant genes was verified by PCR, Southern blot, quantitative real-time PCR (qRT-PCR), and assays of enzymatic activity. The production yield of ligninolytic enzymes was up to four times higher in comparison to previously published reports. These results may represent significant progress toward the stable production of ligninolytic enzymes and the development of an effective fungal strain with promising biotechnological applications.

Effect of Different Carbon Sources on Decolourisation of an Industrial Textile Dye Under Alkaline–Saline Conditions

White-rot fungal strains of Trametes versicolor and Phanerochaete chrysosporium were selected to study the decolourisation of the textile dye, Reactive Black 5, under alkaline-saline conditions. Free and immobilised T. versicolor cells showed 100% decolourisation in the growth medium supplemented with 15gl(-1) NaCl, pH 9.5 at 30°C in liquid batch culture. Continuous culture experiments were performed in a fixed-bed reactor using free and immobilised T. versicolor cells and allowed 85-100% dye decolourisation. The immobilisation conditions for the biomass and the additional supply of carbon sources improved the decolourisation performance during a long-term trial of 40days. Lignin peroxidase, laccase and glyoxal oxidase activities were detected during the experiments. The laccase activity varied depending on carbon source utilized and glycerol-enhanced laccase activity compared to sucrose during extended growth.

Biodegradation of atrazine by Phanerochaete chrysosporium in optimized conditions

Atrazine is an organochloride herbicide widely used for controlling grassy weeds in agriculture. In this study, biodegradation of atrazine with Phanerochaete chrysosporium strain and the optimum conditions of biodegradation were investigated. The amount of atrazine in the medium was determined through HPLC analysis. The biodegradation experiments were carried out indicated that the optimum incubation time was 5 days and the optimum medium pH was 3.0. In addition, the optimum incubation temperature was determined as 30◦C and the optimum agitation rate was determined as 150 rpm in the relevant experiments. The results of these experiments showed that the lignin peroxidase and manganese peroxidase enzymes do not have any effects on atrazin biodegradation.

An oligopeptide transporter gene family in Phanerochaete chrysosporium

Oligopeptide transporters are believed to translocate their substrates across the membrane from the extracellular environment into cell. In the present study, sixteen oligopeptide transporter (OPT) orthologs (PcOPT1 to PcOPT16) were identified in Phanerochaete chrysosporium strain BKMF1767. They were predicted to encode integral membrane proteins with 13 to 16 transmembrane domains. The cDNA and genomic sequences of these genes were confirmed by clone sequencing and Transcriptome Sequencing. Based on sequence similarities, the PcOPT genes can be grouped into three different subfamilies. Comprehensive analysis revealed correlations between gene groupings and gene structures. The PcOPT genes showed differential expression patterns at different metabolic stages or in various stress conditions, suggesting that they may play different functional roles. PcOPT14 was able to mediate the uptake of tetrapeptide KLGL when heterologously expressed in Saccharomyces cerevisiae. This study provides some basic genomic information for OPT genes in P. chrysosporium and will be useful for elucidating their roles in growth, stress response and survival of this organism. Moreover, the results can help us to better understand the complexity of metabolism of P. chrysosporium.

Aspergillus flavus: A potential Bioremediator for oil contaminated soils

Biodegradation is cost-effective, environmentally friendly treatment for oily contaminated sites by the use of microorganisms. In this study, laboratory experiments were conducted to establish the performance of fungal isolates in degradation of organic compounds contained in soils contaminated with petrol and diesel. As a result of the laboratory screening, two natural fungal strains capable of degrading total organic carbons (TOC) were prepared from isolates enriched from the oil contaminated sites. Experiments were conducted in Erlenmeyer flasks under aerobic conditions, with TOC removal percentage varied from 0.7 to 32% depending on strains type and concentration. Strains Phanerocheate chrysosporium and Aspergillus niger exhibited the highest TOC removal percentage of 32 and 21%, respectively, before nutrient addition. TOC removal rate was enhanced after addition of nutrients to incubated flasks. The highest TOC reduction (45%) was estimated after addition of combination of nitrogen, phosphorus and sulphur to Phanerocheate chrysosporium strains. Results of experimental work carried out elucidate that the fungi like Phanerocheate chrysosporium and Aspergillus niger were capabled of producing enzymes at a faster rate to decompose the substrate hydrocarbon and released more CO2 and hence these potential fungi can be utilized effectively as agents of biodegradation in waste recycling process and Bioremediation of oil contaminated sites.

Validation and application of HPLC–ESI-MS/MS method for the quantification of RBBR decolorization, a model for highly toxic molecules, using several fungi strains

A novel analytical method using HPLC–MS/MS operating in selected reaction monitoring (SRM) for evaluation of fungi efficacy to decolorize Remazol Brilliant Blue R (RBBR) dye solution was developed, validated and applied. The method shows high sensibility allowing the detection of 4.6pM of RBBR. Four fungal strains were tested in liquid medium, three strains of Aspergillus (Aspergillus aculeatus, Aspergillus flavus and Aspergillus fumigatus) and Phanerochaete chrysosporium. All fungi were able to degrade the dye, with efficiencies ranging from 40% for P. chrysosporium up to 99% for A. flavus during a 30-day incubation period. During the experiment, increased accumulation of degradation products was observed in A. flavus cultures containing RBBR. Through the use of full scan HPLC–MS technique it was possible to propose the biogenesis of the microbial metabolic degradation pathway. Screening using microorganisms and RBBR may be hereafter used to investigate microbial biodegradation of high toxicity molecules such as dioxins.

Cloning, expression and characterization of an aryl-alcohol dehydrogenase from the white-rot fungus Phanerochaete chrysosporium strain BKM-F-1767

BackgroundThe white-rot fungus Phanerochaete chrysosporium is among the small group of fungi that can degrade lignin to carbon dioxide while leaving the crystalline cellulose untouched. The efficient lignin oxidation system of this fungus requires cyclic redox reactions involving the reduction of aryl-aldehydes to the corresponding alcohols by aryl-alcohol dehydrogenase. However, the biochemical properties of this enzyme have not been extensively studied. These are of most interest for the design of metabolic engineering/synthetic biology strategies in the field of biotechnological applications of this enzyme.ResultsWe report here the cloning of an aryl-alcohol dehydrogenase cDNA from the white-rot fungus Phanerochaete chrysosporium, its expression in Escherichia coli and the biochemical characterization of the encoded GST and His6 tagged protein. The purified recombinant enzyme showed optimal activity at 37°C and at pH 6.4 for the reduction of aryl- and linear aldehydes with NADPH as coenzyme. NADH could also be the electron donor, while having a higher Km (220 μM) compared to that of NADPH (39 μM). The purified recombinant enzyme was found to be active in the reduction of more than 20 different aryl- and linear aldehydes showing highest specificity for mono- and dimethoxylated Benzaldehyde at positions 3, 4, 3,4 and 3,5. The enzyme was also capable of oxidizing aryl-alcohols with NADP + at 30°C and an optimum pH of 10.3 but with 15 to 100-fold lower catalytic efficiency than for the reduction reaction.ConclusionsIn this work, we have characterized the biochemical properties of an aryl-alcohol dehydrogenase from the white-rot fungus Phanerochaete chrysosporium. We show that this enzyme functions in the reductive sense under physiological conditions and that it displays relatively large substrate specificity with highest activity towards the natural compound Veratraldehyde.

Biochemical and Molecular Characterization of Secreted α-Xylosidase from Aspergillus niger

α-Linked xylose is a major component of xyloglucans in the cell walls of higher plants. An α-xylosidase (AxlA) was purified from a commercial enzyme preparation from Aspergillus niger, and the encoding gene was identified. The protein is a member of glycosyl hydrolase family 31. It was active on p-nitrophenyl-α-d-xyloside, isoprimeverose, xyloglucan heptasaccharide (XXXG), and tamarind xyloglucan. When expressed in Pichia pastoris, AxlA had activity comparable to the native enzyme on pNPαX and IP despite apparent hyperglycosylation. The pH optimum of AxlA was between 3.0 and 4.0. AxlA together with β-glucosidase depolymerized xyloglucan heptasaccharide. A combination of AxlA, β-glucosidase, xyloglucanase, and β-galactosidase in the optimal proportions of 51:5:19:25 or 59:5:11:25 could completely depolymerize tamarind XG to free Glc or Xyl, respectively. To the best of our knowledge, this is the first characterization of a secreted microbial α-xylosidase. Secreted α-xylosidases appear to be rare in nature, being absent from other tested commercial enzyme mixtures and from the genomes of most filamentous fungi.

A quantitative method for fungal ligninolytic enzyme screening studies

AbstractScreening is conducted to select a fungus with desired characteristics intended for various applications, e.g. bioremediation and enzyme production. A qualitative method was used in this study for screening of fungal ligninolytic enzyme activities. The fungal ligninolytic activity was correlated with its growth from the screenings to identify a suitable fungus for solid substrate fermentation. Four strains of fungi, namely, Phanerochaete chrysosporium, Pycnoporus sanguineus, Phlebia radiata and Pleurotus sajor‐caju, were screened for their ligninolytic enzyme activities using guaiacol and remazol brilliant blue‐R (RBB‐R) as screening reagents. The screenings were conducted at both, the optimal growth temperature of each fungus and 35 °C. All the fungi, except P. radiata, showed positive guaiacol oxidation and RBB‐R decolourisation activities. On the basis of the results, P. sajor‐caju may be a suitable fungus for use in bioconversion of lignocellulose because it maintained guaiacol oxidation and RBB‐R decolourisation activities at 35 °C. Its halo‐to‐colony area ratios of guaiacol oxidation and RBB‐R decolourisation after 6 days were 7.0 and 2.7, respectively. In the subsequent growth study, the measured colony area was closely correlated with the dry fungal cell weight with a regression value (R2) of 0.971. Thus, the colony size could be used as an indicator of fungal growth if the screening media do not significantly slow the growth of fungus. Copyright © 2010 Curtin University of Technology and John Wiley & Sons, Ltd.

Ligninolytic Enzymes Produced by Phanerohaete Chrysosporium 1038 and Biotransformation of Lignin

ABSTRACTThe influence of nitrogen and Mn2+ ions concentrations in growth medium on the activity of extracellular lignin degradation enzymes: lignin peroxidase (LiP—EC 1.11.1.14), manganese peroxidase (MnP—EC 1.11.1.13) and laccase (Lac—EC 1.10.3.2), produced by Phanerochaete chrysosporium strain 1038, was studied. Evidence for de lignification processes was provided by FTIR spectroscopy after 24 h incubation of lignin samples with concentrated extracellular fluids of activated strain 1038. FTIR spectra showed decrease of carboxylic groups and increase of hydroxylated and methoxylated aliphatic groups, which indicates an oxidative cleavage. The resulting modifications of the lignin structure are due to the low specificity of the ligninolytic enzyme system, consisting of extracellular LiP, MnP and Lac. The addition of 3.5mg/L Mn2+, 63 mg/L Cu2+ and 2.5mM veratryl alcohol is necessary for the activation of lignolytic complex and obtaining of optimal conditions for delignification process after incubation of lignin samples with fluids from the strain. The effect of growth conditions on the enzyme activities of Phanerochaete chrysosporium 1038 and efficiency of delignification procedure are discussed.

The white-rot fungus Phanerochaete chrysosporium: conditions for the production of lignin-degrading enzymes

Investigating optimal conditions for lignin-degrading peroxidases production by Phanerochaete chrysosporium (P. chrysosporium) has been a topic for numerous researches. The capability of P. chrysosporium for producing lignin peroxidases (LiPs) and manganese peroxidases (MnPs) makes it a model organism of lignin-degrading enzymes production. Focusing on compiling and identifying the factors that affect LiP and MnP production by P. chrysosporium, this critical review summarized the main findings of about 200 related research articles. The major difficulty in using this organism for enzyme production is the instability of its productivity. This is largely due to the poor understanding of the regulatory mechanisms of P. chrysosporium responding to different nutrient sources in the culture medium, such as metal elements, detergents, lignin materials, etc. In addition to presenting the major conclusions and gaps of the current knowledge on lignin-degrading peroxidases production by P. chrysosporium, this review has also suggested further work, such as correlating the overexpression of the intra and extracellular proteins to the nutrients and other culture conditions to discover the regulatory cascade in the lignin-degrading peroxidases production process, which may contribute to the creation of improved P. chrysosporium strains leading to stable enzyme production.

Application of improved chemical–mechanical pulp from poplar wood in the packing paper composition

Populus deltoides variety Onda wood was used for obtaining of improved chemical–mechanical pulp (CMP) under laboratory conditions by preliminary treatment of wood chips with three types of enzymes, such as lignin peroxidase, manganese peroxidase and laccase, produced by Phanerochaete chrysosporium strain 1038.

Lignocellulolytic enzyme production from submerged fermentation of paddy straw.

Five strains of cellulolytic bacteria and four strains of Phanerochaete chrysosporium were evaluated for the lignocellulolytic enzyme production during submerged fermentation (SmF) of paddy straw. Extra-cellular enzyme assay for CMCase, FPase, Cellobiase, Xylanase, Lignin peroxidase and Laccase enzymes was performed after 7 and 15 days of submerged fermentation. Cellulomonas cellulans MTCC 23, Cytophaga hutchinsonii NCIM 2338 and Phanerochaete chrysosporium MTCC 787 were found to produce higher lignocellulolytic enzyme activities than rest of the cultures after 15 days of fermentation.

Decolorization of semisolid olive residues of “alperujo” during the solid state fermentation by Phanerochaete chrysosporium, Trametes versicolor, Pycnoporus cinnabarinus and Aspergillus niger

Studies were carried out on decolorization of semisolid olive mill residues called “alperujo” (AL), by four strains of Phanerochaete chrysosporium, Trametes versicolor, Pycnoporus cinnabarinus and Aspergillus niger in solid state frementation (SSF). Fungal strains were selected by their ability to grow on olive mill waste water. The treatment of AL with P. chrysosporium led to higher removal of organic matter and decolorization than P. cinnabarinus and T. versicolor. The strain A. niger leads to a relative improvement of the biodegradability of OMW. Using P. chrysosporium, the treatment of AL substrate in SSF showed an efficient decolorization and an appreciable COD and phenolic content removal only in the presence of a support. Sugarcane bagasse used as support improved the oxygen transfer in the culture. The extracellular fluid of P. chrysosporium (composed mainly of LiP) exhibited high ability to decolorize AL showing the efficiency of the enzyme produced. A percentage of sugarcane bagasse equal to 30% was an optimal condition to improve the growth and the decolorization of AL. The results showed good prospects of using the three basidiomycetes, in particular P. chrysosporium, for the Decolorization of AL.

Decolorization of high concentrations of synthetic dyes by the white rot fungus Bjerkandera adusta strain CCBAS 232

Among thirty different basidiomycetes screened, Bjerkandera adusta strain CCBAS 232, Phanerochaete chrysosporium strain CCBAS 571 and Pleurotus ostreatus strain CCBAS 473 showed the best decolorization properties. B. adusta strain CCBAS 232 was able to decolorize a number of chemically different synthetic dyes (Orange G, Amaranth, Remazol Brilliant Blue R, Cu-phthalocyanine and Poly R-478) at relatively high concentrations of 2–4 g L −1 both on solid and in liquid medium. This strain also grew easily and produced biomass under these conditions. Unlike P. chrysosporium and P. ostreatus, B. adusta was able to efficiently decolorize all tested dyes. These properties and also a good ligninolytic enzyme production predetermine B. adusta strain CCBAS 232 for biotechnological applications.