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1.
Ola M. Gomaa John E. Linz C. A. Reddy 《World journal of microbiology & biotechnology》2008,24(10):2349-2356
Synthetic textile dyes are among the most dangerous chemical pollutants released in industrial wastewater streams. Recognizing
the importance of reducing the environmental impact of these dyes, the ability of the white rot fungus Phanerochaete chrysosporium to decolorize various textile dyes was investigated. This fungus decolorized 6 of the 14 structurally diverse dyes with varying
efficiency (between 14% and 52%). There was no discernable pattern of decolorization even among dyes of the same chemical
class, suggesting that attack on the dyes is relatively non-specific. Among the three dyes which showed >40% decolorization,
Victoria Blue B (VB) was chosen for further analysis because the ability of the fungus to decolorize VB was nearly independent
over a relatively broad concentration range. Blocking lignin peroxidase (LiP) and manganese peroxidase (MnP) production by
the fungus did not substantially affect VB decolorization. Inhibition of laccase production by adding various inhibitors to
shaken cultures reduced VB decolorization significantly suggesting a role for laccase in VB decolorization. When sodium azide
and aminotriazole were used to inhibit endogenous catalase and cytochrome P-450 oxygenase activities, there was 100% and 70%
reduction in VB decolorization, respectively. Adding benzoate to trap hydrogen peroxide-derived hydroxyl radicals resulted
in 50% decolorization of VB. Boiling the extracellular fluid (ECF) for 30 min resulted in approximately 50% reduction in VB
decolorization. Collectively, these data suggest that laccase, and/or oxygenase/oxidase and a heat-stable non-enzymatic factor,
but not Lip and MnP, play a role in VB decolorization by P. chrysosporium. 相似文献
2.
M. Sharari A. Jahan Latibari A. Guillet M. Aurousseau B. Mouhamadou Gh. Rafeiee A. Mirshokraei D. Parsapaghouh 《Biodegradation》2011,22(2):421-430
Biotreatment of bagasse effluent using Phanerochaete chrysosporium (white rot fungus) is investigated. This study confirmed that lignin is the major pollutant component in this effluent followed
by different carbohydrates. The treatment conditions must be very proper, especially in terms of biomass culture to achieve
a successful treatment. The best conditions of temperature, biomass concentration, pH and duration for biotreatment of this
effluent were 35°C, 552 mg l−1, 6 and 5 to 9 days, respectively. Under these conditions, a 9 days long treatment reduced by 98.7% the original biochemical
oxygen demand (of 2,780 mg l−1) and by 98.5% the dissolved chemical oxygen demand (initial 4,200 mg l−1). Moreover, fungal treatment reduced total dissolved solids from 3,950 to 575 mg l−1 and color from 560 mg l−1 PtCo to 111 mg l−1 PtCo. 相似文献
3.
The white-rot fungus Phanerochaete chrysosporium produces glucuronoyl esterase, a recently discovered carbohydrate esterase, during growth on sugar beet pulp. Two putative
genes encoding this enzyme, ge1 and ge2, were isolated and cloned. Heterologous expression in Aspergillus vadensis, Pycnoporus cinnabarinus and Schizophyllum commune resulted in extracellular glucuronoyl esterase activity, demonstrating that these genes encode this enzymatic function. The
amino acid sequence of GE1 was used to identify homologous genes in the genomes of twenty-four fungi. Approximately half of
the genomes, both from ascomycetes and basidiomycetes, contained putative orthologues, but their presence could not be assigned
to any of fungal class or subclass. Comparison of the amino acid sequences of identified and putative glucuronoyl esterases
to other types of carbohydrate esterases (CE) confirmed that they form a separate family of CEs. These enzymes are interesting
candidates for biotechnological applications such as the separation of lignin and hemicellulose. 相似文献
4.
Erika J. Espinosa-Ortiz Graciela Gonzalez-Gil Pascal E. Saikaly Eric D. van Hullebusch Piet N. L. Lens 《Applied microbiology and biotechnology》2015,99(5):2405-2418
The ability of Phanerochaete chrysosporium to reduce the oxidized forms of selenium, selenate and selenite, and their effects on the growth, substrate consumption rate, and pellet morphology of the fungus were assessed. The effect of different operational parameters (pH, glucose, and selenium concentration) on the response of P. chrysosporium to selenium oxyanions was explored as well. This fungal species showed a high sensitivity to selenium, particularly selenite, which inhibited the fungal growth and substrate consumption when supplied at 10 mg L?1 in the growth medium, whereas selenate did not have such a strong influence on the fungus. Biological removal of selenite was achieved under semi-acidic conditions (pH 4.5) with about 40 % removal efficiency, whereas less than 10 % selenium removal was achieved for incubations with selenate. P. chrysosporium was found to be a selenium-reducing organism, capable of synthesizing elemental selenium from selenite but not from selenate. Analysis with transmission electron microscopy, electron energy loss spectroscopy, and a 3D reconstruction showed that elemental selenium was produced intracellularly as nanoparticles in the range of 30–400 nm. Furthermore, selenite influenced the pellet morphology of P. chrysosporium by reducing the size of the fungal pellets and inducing their compaction and smoothness. 相似文献
5.
Lee H Choi YS Kim MJ Huh NY Kim GH Lim YW Kang SM Cho ST Kim JJ 《Folia microbiologica》2010,55(5):447-453
Seventy-nine white rot strains were screened to determine if they had the potential for use in the degradation of oligocyclic
aromates (PAHs) by measuring their dye-decoloration rate. Fourteen strains that were selected based on their dye-decoloration
rate were then evaluated for the ability to tolerate various levels of PAHs spiked in agar medium. The ability of white rot
fungi to degrade 3- or 4-ring PAHs (anthracene, phenanthrene, fluoranthene, pyrene) was determined. Two strains of Phanerochaete sordida (KUC8369, KUC8370) were possible PAHs degraders, degrading a significantly greater amount of phenanthrene and fluoranthene
than the culture collection strain P. chrysosporium (a known PAHs degrader). The production of manganese peroxidase, the only extracellular ligninolytic enzyme detected during
the cultivation, was evaluated. 相似文献
6.
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. 相似文献
7.
The potential use of fungal pellets for decolorization of the textile dyeing wastewater was evaluated. The live pellets of the fungus Phanerochaete chrysosporium were found to remove more than 95% of the color of this wastewater within 1 d. The dye-removal capacity was a function of time and was proportional to the agitation rate; the optimum temperature was 30 degrees C. Both live and dead pellets were further examined in a repeated-batch mode for 5 d. The decolorization performance of live pellets remained high and stable for 5 d and they showed twice to thrice higher decolorization capacity than dead pellets. 相似文献
8.
Degradation of 4-nitrophenol by the lignin-degrading basidiomycete <Emphasis Type="Italic">Phanerochaete chrysosporium</Emphasis> 总被引:2,自引:0,他引:2
The fungal metabolism of 4-nitrophenol (4-NP) was investigated using the lignin-degrading basidiomycete, Phanerochaete chrysosporium. Despite its phenolic feature, 4-NP was not oxidized by extracellular ligninolytic peroxidases. However, 4-NP was converted to 1,2-dimethoxy-4-nitrobenzene via intermediate formation of 4-nitroanisole by the fungus only under ligninolytic conditions. The metabolism proceeded via hydroxylation of the aromatic ring and methylation of phenolic hydroxyl groups. Although the involvement of nitroreductase in the metabolism of 2,4-dinitrotoluene by many aerobic and anaerobic microorganisms including P. chrysosporium has been reported, no formation of 4-aminophenol was observed during 4-NP metabolism. The formation of 1,2-dimethoxy-4-nitrobenzene was effectively inhibited by exogenously added piperonyl butoxide, a cytochrome P450 inhibitor, suggesting that cytochrome P450 is involved in the hydroxylation reaction. Thus, P. chrysosporium seems to utilize hydroxylation and methylation reactions to produce a more susceptible structure for an oxidative metabolic system. 相似文献
9.
Whole genome sequencing of the model white rot basidiomycete Phanerochaete chrysosporium has revealed the largest P450 contingent known to date in fungi, along with related phase I and phase II metabolic genes
and signaling cascade genes. As a part of their functional characterization, genome-wide expression profiling under physiologically
distinct conditions, nutrient-limited (ligninolytic) and nutrient-rich (non-ligninolytic), was investigated using a custom-designed
70-mer oligonucleotide microarray developed based on 190 target genes and 23 control genes. All 150 P450 genes were found
to be expressible under the test conditions, with 27 genes showing differential expression based on a >twofold arbitrary cut-off
limit. Of these, 23 P450 genes were upregulated (twofold to ninefold) in defined high-nitrogen cultures whereas four genes
were upregulated (twofold to twentyfold) in defined low-nitrogen cultures. Furthermore, tandem P450 member genes in ten of
the 16 P450 genomic clusters showed nonassortative regulation of expression reflecting their functional diversity. Full-length
cDNAs for two of the high-nitrogen upregulated genes pc-hn1 (CYP5035A1) and pc-hn2 (CYP5036A1) and partial cDNA for a low-nitrogen upregulated gene pc-ln1 (CYP5037A1) were cloned and characterized. The study provided first molecular evidence for the presence of active components
of the cAMP- and MAP kinase-signaling pathways in a white rot fungus; four of these components (cpka and ste-12 of cAMP pathway and two MAP kinases, mps1 and sps1) were significantly upregulated (fourfold to eightfold) under nutrient-limited conditions, implying their likely role in
the regulation of gene expression involved in secondary metabolism and biodegradation processes under these conditions. 相似文献
10.
A. M. Montiel-González F. J. Fernández N. Keer A. Tomasini 《Applied microbiology and biotechnology》2009,84(2):335-340
Fungal peroxidases and phenoloxidases are widely used in aromatic toxic compounds degradation. Peroxidases, such as lignin
peroxidase and manganese peroxidase, as well as laccases are mainly produced by basidiomycetes and to a lower extent by other
fungi, such as ascomycetes. Peroxidase-encoding genes have been described and homologous expression has been achieved in basidiomycetes.
Heterologous expression has also been achieved in some non-producing peroxidase ascomycetes, like Penicillium and Aspergillus. In this work, heterologous expression of peroxidase-encoding genes, lignin peroxidase, and manganese peroxidase was achieved
in a zygomycete producing only phenoloxidases (Amylomyces rouxii), aimed at coupling two different pathways used in nature for PCP removal in only one microbial strain. The ability of PCP
removal was assayed with one of the obtained transformants, resulting in increased activity with respect to the ability of
the parental strain cultured free of the inducer tyrosine (95% and 45%, respectively, of the initial PCP (12.5 mg L−1) in 120 h, or 100% and 49%, respectively, of the initial PCP after 144 h of liquid culture). 相似文献
11.
To prepare homologous DNA fragments as restriction fragment length polymorphism (RFLP) markers, the genes encoding phenol oxidase, chitinase, and xylanase were amplified from genomic DNA of Rosellinia necatrix strains. RFLP analysis using the amplified DNA fragments as probe was carried out, with segregation of the markers among two sets of F1 progenies isolated from an independent perithecium. RFLP was frequently found using rpo1 as the RFLP marker among strains of R. necatrix, which was isolated from single ascospores and the circumference of the perithecium. In each set, RFLPs of some F1 progenies were different from that of the parent strain. Random amplified polymorphic DNA (RAPD) also revealed that several strains, which were of different genotypes from the parent strain, were contained in the single ascospore culture isolated from the same perithecium. From these results, it is suggested that another strain, which was genetically different, was required for mating and development of the ascus in R. necatrix. Therefore, the life cycle in R. necatrix was presumed to be heterothallism. This is the first report about a heterothallic life cycle in R. necatrix. 相似文献
12.
S. V. Nikiforova N. N. Pozdnyakova O. E. Makarov M. P. Chernyshova O. V. Turkovskaya 《Microbiology》2010,79(4):456-460
The effect of cultivation conditions on chrysene bioconversion by the fungus Pleurotus ostreatus D1 was shown. Under the laccase production conditions, transformation of this polycyclic aromatic hydrocarbon occurs with
accumulation of the quinone metabolite. Under both the laccase and versatile peroxidase production conditions, chrysene degradation
occurs, with the stages leading to phthalic acid formation and its further utilization. The formation of phthalic acid as
a metabolite of chrysene degradation by white rot fungi was revealed for the first time. The data obtained suggest that the
laccase revealed on the mycelial surface and the extracellular laccase are probably involved at the initial stages of chrysene
metabolism, whereas versatile peroxidase seems to be required for oxidizing the metabolites formed. 相似文献
13.
Summary A ubiquitous white rot fungus Schizophyllum commune was used for the first time to study the degradation of ferulic acid. Vanillic acid was observed as one of the major products of ferulic acid catabolism, with vanillin formed as an intermediate. Almost 99.9% ferulic acid with a initial concentration of 5 mM was consumed by this fungus after 16 days of incubation at 37 °C. 相似文献
14.
Melanin was decolorized by lignin peroxidase fromPhanerochaete chrysosporium. This decolorization reaction showed a Michaelis-Mentens type relationship between the decolorization rate and concentration
of two substrates: melanin and hydrogen peroxide. Kinetic constants of the decolorization reaction were 0.1 OD475/min (V
max) and 99.7 mg/L (K
m) for melanin and 0.08 OD475/min (V
max) and 504.9 μM (K
m) for hydrogen peroxide, respectively. Depletion of hydrogen peroxide interrupted the decolorization reaction, indicating
the essential requirement of hydrogen peroxide. Pulsewise feeding of hydrogen peroxide continued the decolorizing reaction
catalyzed by lignin peroxidase. These results indicate that enzymatic decolorization of melanin has applications in the development
of new cosmetic whitening agents. 相似文献
15.
Two repeated DNA sequences isolated from a partial genomic DNA library of Helianthus annuus, p HaS13 and p HaS211, were shown to represent portions of the int gene of a Ty3 /gypsy retroelement and of the RNase-Hgene of a Ty1 /copia retroelement, respectively. Southern blotting patterns obtained by hybridizing the two probes to BglII- or DraI-digested genomic DNA from different Helianthus species showed p HaS13 and p HaS211 were parts of dispersed repeats at least 8 and 7 kb in length, respectively, that were conserved in all species studied. Comparable hybridization patterns were obtained in all species with p HaS13. By contrast, the patterns obtained by hybridizing p HaS211 clearly differentiated annual species from perennials. The frequencies of p HaS13- and p HaS211-related sequences in different species were 4.3x10(4)-1.3x10(5) copies and 9.9x10(2)-8.1x10(3) copies per picogram of DNA, respectively. The frequency of p HaS13-related sequences varied widely within annual species, while no significant difference was observed among perennial species. Conversely, the frequency variation of p HaS211-related sequences was as large within annual species as within perennials. Sequences of both families were found to be dispersed along the length of all chromosomes in all species studied. However, Ty3 /gypsy-like sequences were localized preferentially at the centromeric regions, whereas Ty1/ copia-like sequences were less represented or absent around the centromeres and plentiful at the chromosome ends. These findings suggest that the two sequence families played a role in Helianthusgenome evolution and species divergence, evolved independently in the same genomic backgrounds and in annual or perennial species, and acquired different possible functions in the host genomes. 相似文献
16.
Studying Pneumocystis has proven to be a challenge from the perspective of propagating a significant amount of the pathogen in a facile manner.
The study of several fungal pathogens has been aided by the use of invertebrate model hosts. Our efforts to infect the invertebrate
larvae Galleria
mellonella with Pneumocystis proved futile since P. murina neither caused disease nor was able to proliferate within G. mellonella. It did, however, show that the pathogen could be rapidly cleared from the host. 相似文献
17.
Noel H. Holmgren 《Brittonia》2018,70(1):115-139
A revision of Penstemon sect. Saccanthera subsect. Serrulati includes a new species (P. salmonensis), a new variety (P. triphyllus var. infernalis), and the elevation of a subspecies to species (P. curtiflorus), bringing the total number of species to eight, which are keyed and described, complete with nomenclature and type citations. 相似文献
18.
A genetic transformation system has been developed for callus cells of Crataegus
aronia using Agrobacterium
tumefaciens. Callus culture was established from internodal stem segments incubated on Murashige and Skoog (MS) medium supplemented with
5 mg l−1 Indole-3-butyric acid (IBA) and 0.5 mg l−1 6-benzyladenine (BA). In order to optimize the callus culture system with respect to callus growth and coloration, different
types and concentrations of plant growth regulators were tested. Results indicated that the best average fresh weight of red
colored callus was obtained on MS medium supplemented with 2 mg l−1 2,4-dichlorophenoxyacetic acid (2,4-D) and 1.5 mg l−1 kinetin (Kin) (callus maintenance medium). Callus cells were co-cultivated with Agrobacterium harboring the binary plasmid pCAMBIA1302 carrying the mgfp5 and hygromycin phosphotransferase (hptII) genes conferring green fluorescent protein (GFP) activity and hygromycin resistance, respectively. Putative transgenic calli
were obtained 4 weeks after incubation of the co-cultivated explants onto maintenance medium supplemented with 50 mg l−1 hygromycin. Molecular analysis confirmed the integration of the transgenes in transformed callus. To our knowledge, this
is the first time to report an Agrobacterium-mediated transformation system in Crataegus
aronia. 相似文献
19.
The maT clade of transposons is a group of transposable elements intermediate in sequence and predicted protein structure to mariner and Tc transposons, with a distribution thus far limited to a few invertebrate species. We present evidence, based on searches of publicly available databases, that the nematode Caenorhabditis briggsae has several maT-like transposons, which we have designated as CbmaT elements, dispersed throughout its genome. We also describe two additional transposon sequences that probably share their evolutionary history with the CbmaT transposons. One resembles a fold back variant of a CbmaT element, with long (380-bp) inverted terminal repeats (ITRs) that show a high degree (71%) of identity to CbmaT1. The other, which shares only the 26-bp ITR sequences with one of the CbmaT variants, is present in eight nearly identical copies, but does not have a transposase gene and may therefore be cross mobilised by a CbmaT transposase. Using PCR-based mobility assays, we show that CbmaT1 transposons are capable of excising from the C. briggsae genome. CbmaT1 excised approximately 500 times less frequently than Tcb1 in the reference strain AF16, but both CbmaT1 and Tcb1 excised at extremely high frequencies in the HK105 strain. The HK105 strain also exhibited a high frequency of spontaneous induction of unc-22 mutants, suggesting that it may be a mutator strain of C. briggsae. 相似文献
20.
Fluorescein derivatives added into the growth medium were decolorized during submerged cultivation of Phanerochaete chrysosporium. The highest decrease of absorbance A450 was observed in the growth phase regardless of the presence of inducers Tween 80 or poly(ethylene glycol) (PEG). Fluorescein linked to PEG was prepared and, after addition to cultures, shown to stimulate the production of lignin peroxidase. Passing of fluorescing substances into hyphae (observed by confocal microscopy) showed that they were concentrated on some structures inside hyphae. 相似文献