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Formaldehyde as a proof and response to various kind of stress in some Basidiomycetes.

The influence of cadmium chloride and/or high temperature on the level of selected parameters were examined in both medium and mycelium of some Basidiomycetes belonging to white-rot fungi: Abortiporus biennis, Trametes versicolor and Cerrena unicolor. We investigated changes in the formaldehyde (FA) level and in the level of superoxide radical anions (SR). Accordingly, the capacity of three enzymes was also studied: two enzymes of the cellular antioxidative system - superoxide dismutase (SOD; EC 1.15.1.1), and catalase (CAT; EC 1.11.1.6), and laccase (LAC; EC 1.10.3.2) the main lignin-modifying enzyme, which is produced by white-rot fungi. During the first 24 hours after application of separate stressors, or jointly with two stressors to 10-day-old cultivation, changes in all selected parameters were observed. Moreover, we found significant changes in the levels of extracellular SR, FA and extra- and intracellular activity of LAC. Simultaneous action of two stressors in the fungal cultures decreased the extracellular LAC level, intracellular CAT activity and the level of SR in the medium compared to the control values, while using the two stress factors separately would strongly make these values increase. Stressful conditions brought a rapid increase in the level of FA in all fungal species. The results of our study, carried out on selected strains of Basidiomycetes, seem to have shown that: (I) LAC, the lignin-modifying enzyme, may have an important application in fungal stress response, and take part in the cross-protection between responses to heat shock and cadmium resistance; (2) the oxidative burst as a result of cadmium and high temperature treatment is an additional factor to damage fungal cells; (3) FA may be a determining factor in the phases of fungal stress syndrome.

Basidiomycota↗

[Analysis of higher basidiomycetous mitochondrial DNA with four-GC-cutter restriction enzymes].

The mitochondrial DNA band patterns emerged from basidiomycetous genomic DNA digested with four-GC-cutter restriction enzymes, HaeIII, CfoI and MspI, were reported in this paper. It was demonstrated that mtDNAs of higher basidiomycetes had abundant diversity after comparison of their band patterns, summated sizes, the number of fragments and homology among 12 strains of Agaricales, Aphyllophorales. The results also showed that the technique, displaying fungal mtDNA bands directly from their total DNA, would be more efficient and sensitive for analyses of fungal mtDNA RFLP if several four-GC-cutter restriction enzymes, instead of one, were used.

Agaricales↗

[Antitumor effects of intratumoral injection of Basidiomycetes preparations].

The antitumor effects of Basidiomycetes preparations in an experimental mouse model, the "double grafted tumor system" were analyzed. Some BRMs prevented metastases by utilizing the anti-tumor immunological cascade reactions, which activates macrophages in the body. The following Basidiomycetes preparations were analyzed: PSK was a hot water extract of cultured mycelia from Coliolus versicolor and a protein bound beta-glucan. Matsumax was extracted from mycelia of Tricholoma matsutake and was a protein bound (38%) a-glucan. The Agaricus preparation was extracted from fruit bodies of Agaricus blazei and a protein-bound (17%) a-glucan, beta-glucan. Himematsutake preparation was extracted from fruit body of Agaricus blazei (Himematsutake) and a protein bound (5%) glucan. Lentinan was purified from fruit bodies of Lentinus edodes and is a purified beta-glucan. PSK cured both primary and metastatic tumors in the double grafted tumor system. Lentinan inhibited the growth of neither primary nor metastatic tumors. Matsumax and Agaricus preparation cured primary tumor and inhibited the growth of metastatic tumor. Himematsutake preparation inhibited the growth of primary tumor. Immunosuppresive acidic protein (IAP) is produced by activated mactrophates. The PSK, Matsumax, Agaricus preparation and Himematsutake preparation induced IAP but Lentinan did not.

Agaricus↗

Degradation of crystalline cellulose by the brown-rot basidiomycete Fomitopsis palustris.

This study demonstrated that the brown rot basidiomycete Fomitopsis palustris was able to degrade crystalline cellulose (Avicel). This fungus could also produce the three major cellulases (exoglucanases, endoglucanases, and beta-glucosidase) when the cells were grown on 2.0% Avicel. Avicel degraded by F. palustris showed a decrease in relative crystallinity from 83% to 78.5% after 14 days of incubation. The characterization study indicated that optimum pH was 4.5 and optimum temperature was 70 degrees C for exoglucanase (cellobiohydrolase) activity. Hydrolysis of Avicel by the crude enzyme from F. palustris yielded 1.6 mg/ml of glucose after 43 h, which corresponded to a cellulose conversion degree of 3.2%. Therefore, this study revealed for the first time that the brown rot basidiomycete F. palustris produces cellulases capable of yielding soluble sugars from crystalline cellulose.

Biodegradation, Environmental↗

[Carboxylic proteinase from the basidiomycete Russula decolorans Fr 0456].

A carboxylic proteinase has been isolated from a cultural filtrate of the basidiomycet Russula decolorans Fr 0456. A sequential chromatography on biospecific adsorbents containing polypeptide antibiotics gramicidin S and bacitracin used as ligands resulted in a 186-fold purification and 48% yield of the enzyme. The molecular weight of the enzyme is 35 000, pH-optimum of hemoglobin hydrolysis is 2,2, the isoelectric point lies at 4,9. The enzyme revealed a pronounced milk-clotting activity and is completely inactivated by the specific inhibitors of carboxylic proteinases--N-diazo-acetyl-N'-2,4-dinitrophenylethylenediamine and pepstatin. Its amino acid composition was also found to be similar to that of the carboxylic proteinases isolated from microscopic fungi. The data obtained suggest that the carboxylic proteinase from the basidiomycet Russula decolorans Fr 0456 is closely related to pepsin-like carboxylic proteinases, particularly to those produced by microscopic fungi.

Amino Acids↗

Cellular graviperception in the basidiomycete Flammulina velutipes--can the nuclei serve as fungal statoliths?

In search for the cellular mechanisms of graviperception in basidiomycete fruit bodies, nuclear and vacuole motility was investigated in the fungus, Flammulina velutipes. In this organism, hyphal nuclei are closely linked with the actin cytoskeleton, which is involved in gravity perception. Active motion of the nuclei appears aligned with the axis of gravity, and is maintained after spatial reorientation of the cell. The vacuoles showed low motility not aligned with the gravity axis at all. The nuclear density was determined with 1.22 g/cm3. Calculation of the forces exerted by the nuclei shows that nuclear displacement in the submicrometer range already fulfills the physical minimum condition for a statolith. Based on these findings, a function of nuclei as statoliths in basidiomycete hyphae is proposed.

Basidiomycota↗

Rare fatal simultaneous mould infection of the lung caused by Aspergillus flavus and the basidiomycete Coprinus sp. in a leukemic patient.

The basidiomycete Coprinus sp. was isolated repeatedly from bronchial secretions and bronchoalveolar lavage of a 40-year-old woman suffering from a relapse of acute lymphoblastic leukemia 5 years after she underwent autologous bone marrow transplantation. Post-mortem microbiological investigation of lung tissue revealed simultaneously growing Coprinus sp. and Aspergillus flavus. Histopathological examination of the lung demonstrated septate hyphae characteristic of both Aspergillus and Coprinus. The basidiomycete Coprinus sp. should be considered as a potential opportunistic pathogen because of its excellent growth at 37 degrees C.

Adult↗

PRODUCTION OF OOSPOREIN AND ITS LEUCO FORM BY BASIDIOMYCETE SPECIES.

Oosporein, a dibenzoquinone pigment previously obtained from an Ascomycete and from several species of Fungi Imperfecti, has been isolated from two basidiomycete species of the genus Phlebia. The leuco form, not previously reported as a natural product, accompanied the quinone in culture liquids.

Ascomycota↗

Transformations of progesterone by basidiomycetes.

A total of 254 basidiomycete cultures have been examined for their action on progesterone. Of these, 54 showed transformation products by thin-film and gas-liquid chromatography. The major product formed by eight of these organisms acting on progesterone has been isolated and identified.

Basidiomycota↗

POLYOL METABOLISM IN THE BASIDIOMYCETE SCHIZOPHYLLUM COMMUNE.

Niederpruem, Donald J. (Indiana University Medical Center, Indianapolis), Amtul Hafiz, and Lyle Henry. Polyol metabolism in the basidiomycete Schizophyllum commune. J. Bacteriol. 89:954-959. 1965.-The polyol metabolism of intact cells and extracts of the wood-rotting mushroom Schizophyllum commune was investigated during the developmental cycle. Exogenous polyols stimulated the cellular respiration of germlings, but were without effect on that of ungerminated basidiospores. Requisite enzymes of polyol metabolism were demonstrated in extracts of spores and of subsequent stages of development. Oxidation of mannitol and sorbitol appeared to be coupled to nicotinamide adenine dinucleotide (NAD) reduction and was favored in alkaline medium. Ketohexose formation was shown during mannitol oxidation, and the NAD-dependent oxidation of xylitol yielded ketopentose. Xylitol oxidation with nicotinamide adenine dinucleotide phosphate (NADP) as hydrogen acceptor led to pentose formation. Oxidation of reduced NAD was enhanced by fructose but not by sorbose. Reduction of aldohexose and pentose was dependent upon reduced NADP, and pentose reductase was maximal at pH 6.8. The specific activity of mannitol dehydrogenase was highest in extracts of vegetative mycelium. Growth in either glucose or xylose media had no significant effect on enzymes of polyol metabolism.

Alcohols↗

Influence of morphology and rheology on the production characteristics of the basidiomycete Cyathus striatus.

The influence of the pellet morphology of the basidiomycete Cyathus striatus on the production of the antibiotics striatals A, B, and C was investigated. The main operating parameters in fermenters of different sizes were the tip speed and the volumetric power input. Different methods were developed for quantification of morphological characteristics. The apparent viscosity of the suspension was measured with a cylinder rheometer. Sediment density was measured with a sedimentation apparatus. Particle size distributions were recorded with an image analysis system. By means of the presented measuring methods, morphological characteristics could be determined and enabled an early assessment of the fermentation course and the antibiotics production. During the exponential growth phase of the fungus the relative sediment height correlated with the biomass concentration. The pellet morphology at this stage influenced the later production of striatals. The yield of the striatals was markedly influenced by pellet size and sediment density. Since these morphological characteristics determine the rheological properties of the culture the measurement of the apparent viscosity of the culture in the production phase allowed predictions of the production yield.

Anti-Bacterial Agents↗

An expression system for the functional analysis of pheromone genes in the tetrapolar basidiomycete Schizophyllum commune.

The investigation of putative pheromone genes of basidiomycetes has been difficult since the small open reading frames are essentially annotated on the basis of a C-terminal farnesylation signal. In order to identify the functional reading frame, expression of small DNA fragments in the fungus is necessary. The expression system developed in the presented paper allows fusion to the promoter of the tef1 gene encoding the constitutively and highly expressed translation elongation factor EF1alpha. This system has been shown to be functional using an easily selectable gene, ura1. The application to identification of functional pheromone genes has been shown with the newly detected bap2(4) gene. The Bap2(4) pheromone is the first Balpha pheromone gene activating only a single receptor specificity.

Amino Acid Sequence↗

Analysis of expressed sequence tags from the anamorphic basidiomycetous yeast, Pseudozyma antarctica, which produces glycolipid biosurfactants, mannosylerythritol lipids.

Pseudozyma antarctica T-34 secretes a large amount of biosurfactants (BS), mannosylerythritol lipids (MEL), from different carbon sources such as hydrocarbons and vegetable oils. The detailed biosynthetic pathway of MEL remained unknown due to lack of genetic information on the anamorphic basidiomycetous yeasts, including the genus Pseudozyma. Here, in order to obtain genetic information on P. antarctica T-34, we constructed a cDNA library from yeast cells producing MEL from soybean oil and identified the genes expressed through the creation of an expressed sequence tags (EST) library. We generated 398 ESTs, assembled into 146 contiguous sequences. Based upon a BLAST search similarity cut-off of E<or=10(-5), 21.4% of all contigs were orphan, while 78.6% showed similarity to sequences in the protein database; 60.3% of all contiguous sequences shared significant identities to hypothetical protein of Ustilago maydis, which is a smut fungus and BS producer. Based on the gene expression study using real-time reverse transcriptase-PCR, the predicted genes, such as mannosyltranferase and acyltransferase, were demonstrated to be highly involved in MEL biosynthesis in soybean oil-grown cells.

Acyltransferases↗

Isozymes of lignin peroxidase and manganese(II) peroxidase from the white-rot basidiomycete Trametes versicolor. I. Isolation of enzyme forms and characterization of physical and catalytic properties.

The basidiomycete Trametes versicolor is a white-rot fungus and a potent degrader of lignin. The development of extracellular enzyme activities in the fungal culture under physiological conditions of secondary metabolism was investigated. Using the culture medium as starting material a large number of peroxidase forms were purified by the use of chromatographic techniques. Sixteen forms of lignin peroxidase and five forms of manganese(II) peroxidase were separated and the majority of these enzymes was characterized with respect to isoelectric point, molecular mass, and specific enzyme activity. The manganese(II) peroxidases showed a lower isoelectric point (pI 3.2-2.9) and a slightly higher molecular mass (44-45 kDa) than the lignin peroxidases (pI 3.7-3.1, and 41-43 kDa). Specific enzyme activities for the forms of lignin peroxidase, using veratryl alcohol as the substrate, were found to differ considerably. Certain differences in the specific enzyme activity were also observed among the forms of manganese(II) peroxidase. A multitude of peroxidase forms has previously been encountered in another white-rot fungus, Phanerochaete chrysosporium. The discovery that it also occurs in T. versicolor would suggest that this multiplicity could be a common feature among white-rot fungi and may be essential for the biodegradation of lignin.

Basidiomycota↗

Isozymes of lignin peroxidase and manganese(II) peroxidase from the white-rot basidiomycete Trametes versicolor. II. Partial sequences, peptide maps, and amino acid and carbohydrate compositions.

The basidiomycete Trametes versicolor, a white-rot fungus and potent degrader of lignin, produces multiple forms of extracellular peroxidases. Nine of these forms, six lignin peroxidases and three manganese(II) peroxidases, purified as described in the preceding paper, were characterized by amino-terminal sequencing, amino acid analyses, carbohydrate analyses, or peptide mapping. For two of the lignin peroxidase forms, tryptic peptides were isolated and sequenced to an extent corresponding to about 40 and 30%, respectively, of the primary structure. Eight of the nine peroxidases investigated were found to possess unique amino-terminal regions. A comparison of the sequences shows 57% of the residues to be identical, indicating a common ancestry for the lignin peroxidase and the manganese(II) peroxidase. The degree of identity among the five lignin peroxidases is about 80% and among the three manganese(II) peroxidases about 70%. Pairwise comparisons of the sequences disclosed that some of the lignin peroxidases are very closely related, either identical or differing only in a single amino acid residue of the thirty-five investigated. These close relationships are also supported by peptide mapping and by similarities in amino acid compositions. Tyr is absent in all isozymes. Lignin and manganese(II) peroxidases showed the presence of glucosamine and mannose in an amount corresponding to 3 to 6% of the molecular mass of the proteins. The carbohydrate compositions are compatible with the presence of 1, 2, and 3 sites of N-glycosylation. The results obtained strongly suggest that the complexity in the peroxidase pattern displayed by the fungus (T. Johansson and P.O. Nyman, Arch. Biochem. Biophys. 300, 49-56, 1993) can largely be accounted for by a heterogeneity at the gene level, probably in the form of multiple structural genes. Two recently published genes from genomic clones of T. versicolor are identical in sequence to two of the lignin peroxidases characterized here.

Amino Acid Sequence↗

The complete amino acid sequences of two serine proteinase inhibitors from the fruiting bodies of a basidiomycete, Pleurotus ostreatus.

The complete amino acid sequences of two isomeric endogenous inhibitors, IA-1 and IA-2, both of which specifically inhibit an intracellular serine proteinase (proteinase A) purified from the fruiting bodies of a higher basidiomycete, Pleurotus ostreatus, were determined. Both inhibitors are acidic polypeptides with respective molecular masses of 8307 and 8244 Da, as determined by plasma desorption mass spectral analyses, and their N-terminal serine residue is blocked by acetylation. The fragments generated from the inhibitors by proteolytic and chemical cleavages were subjected to amino acid composition, sequence, and mass spectral analyses. The sequence and molecular mass information for the peptides established that the inhibitors both consisted of 76 amino acid residues and differed from each other in that aspartic acid and glutamic acid residues at residues 12 and 15 of IA-1 were replaced by glycine and aspartic acid in IA-2, respectively. The molecular masses of IA-1 and IA-2 were calculated to be 8309 and 8237, based on the sequence data. The action of carboxypeptidase Y on IA-1 resulted in a complete loss of the inhibitory activity along with successive release of glutamine and threonine from the C-terminus. Cyanogen bromide cleavage of Met38-Pro39 and Met41-Lys42 in IA-1 and hydroxylamine degradation of IA-2 completely abolished their inhibitory activity. These results suggest that the whole molecules of both inhibitors are essential to their inhibitory activities. Their structural resemblance to propeptides of subtilisin family proteinases revealed their mechanism of action.

Amino Acid Sequence↗

1,4-Benzoquinone reductase from basidiomycete Phanerochaete chrysosporium: spectral and kinetic analysis.

The reaction mechanism of a 1,4-benzoquinone reductase from the wood-rotting basidiomycete Phanerochaete chrysosporium was investigated. The native, oxidized, FMN-containing enzyme was reduced quantitatively by NADH and the resulting reduced enzyme was reoxidized in the presence of one equivalent of 2,6-di-methoxy-1,4-benzoquinone (DMBQ). The stoichiometry of NADH oxidation versus DMBQ reduction is 1:1. The enzyme catalyzes the reduction of quinones to hydroquinones by a ping-pong steady-state mechanism. However, inhibition is observed at low NADH concentrations. Quinone products derived from the autooxidation of the unstable compounds 1,2,4-trihydroxybenzene and 5-chloro-2,3,4-trihydroxybenzene also appear to be substrates for the quinone reductase. The enzyme reduces the one-electron acceptors ferricyanide and ferricytochrome c (Cc3+) with rates of 58.4 and 0.08%, respectively, compared to DMBQ. The stoichiometry of NADH oxidation versus ferricyanide reduction is 1:2. In the presence of quinones the rates of Cc3+ and ferricyanide reduction are increased, owing to the nonenzymatic reduction of these acceptors by enzyme-generated hydroquinone products. Dicumarol and Cibacron blue are competitive inhibitors with respect to NADH, with Ki values of 2.1 and 0.30 microM, respectively. Reconstitution of the apoprotein with FMN yields a fully active enzyme at an FMN-to-protein ratio of 2:1, suggesting that the flavin content of the enzyme is two molecules of FMN per dimer.

Basidiomycota↗