Polyporaceae

Two laccase isoenzymes produced by Pleurotus eryngii were purified to electrophoretic homogeneity (42- and 43-fold) with an overall yield of 56.3%. Laccases I and II from this fungus are monomeric glycoproteins with 7 and 1% carbohydrate content, molecular masses (by sodium dodecyl sulfate-polyacrylamide gel electrophoresis) of 65 and 61 kDa, and pIs of 4.1 and 4.2, respectively. The highest rate of 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate) oxidation for laccase I was reached at 65 degrees C and pH 4, and that for laccase II was reached at 55 degrees C and pH 3.5. Both isoenzymes are stable at high pH, retaining 60 to 70% activity after 24 h from pH 8 to 12. Their amino acid compositions and N-terminal sequences were determined, the latter strongly differing from those of laccases of other basidiomycetes. Antibodies against laccase I reacted with laccase II, as well as with laccases from Pleurotus ostreatus, Pleurotus pulmonarius, and Pleurotus floridanus. Different hyd...

Two isoforms of laccase produced from the culture supernatant of Pycnoporus sanguineus were partially purified by phenyl-Sepharose chromatography. Molecular masses of the enzymes were 80 kDa (Lac I) and 68 kDa (Lac II). Optimum activity of Lac I was at pH 4.8 and 30 degrees C, and Lac II was at pH 4.2 and 50 degrees C over 5 min reaction. The Km values of enzymes toward syringaldazine were 10 microM: (Lac I) and 8 microM: (Lac II). Sodium azide inhibited Lac I (85%) and Lac II (75%) activities.

Aqueous extract of Inonotus obliquus was hydrolyzed in dilute hydrochloric acid. The products were extracted applying organic solvents, and separated chromatographically on a silica gel-packed column. Eluted fractions were analyzed by means of GC-MS. The presence of hydrocarbons, alcohols, phenols and various carbonyl compounds in analyzed fractions has been detected and quantified. Preliminarily experiments on the influence of certain separated samples on the proliferation of A549 human lung carcinoma cells were performed. Therefore, we hypothesize that the major antiproliferative effects are related to the presence of benzaldehyde, which is a benzyl alcohol metabolite formed in situ in the cells culture with the yield moderated by the presence of trace amounts of "high molecular mass compounds".

A thermotolerant and halotolerant strain of Pycnoporus sanguineus was isolated from an oil-polluted site in a tropical area located in Veracruz, Mexico. This strain was able to grow at 47 degrees C and in culture medium containing 500 mM NaCl. The strain was also tolerant to the presence of 30,000 ppm of crude Maya oil. A 68-kDa protein purified from submerged cultures exhibited laccase activity towards 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), guaiacol, syringaldazine, and o-dianisidine, for which it presented the highest affinity (Km = 43 microM). Two-dimensional gel electrophoresis analysis showed that, unusual for laccases, the enzyme has two active isoforms, with isoelectric points of 7.00 and 7.08. The purified enzyme showed high thermostability, retaining 40% of its original activity after 3 h at 60 degrees C. This property seems to correlate with a long "shelf-life," given that at 40 degrees C enzyme activity was only gradually lost over a 5...

Genetic variation within and among one Finnish and three Swedish populations of Fomitopsis pinicola (Schwarts: Fr.) Karst. were studied by amplifying DNA from haploid isolates originating from single spore cultures using two arbitrary primers. Analysis offspring from single fruit bodies revealed only three pairs of codominant alleles among 42 variable genetic markers, the remaining 38 segregated independently. Genetic similarity was measured in terms of Euclidean distance. Individuals in the Finnish population tended to form a distinct cluster in the principal component analysis. Variation within and among populations/regions was partitioned by Analysis of Molecular Variance-AMOVA. Within population variation accounted for 91.6% of the total genetic variation. The remaining 7.68% was accounted for by variation between the Finnish population and each of the three Swedish ones. Variation among the Swedish populations accounted for only 0.72% of the total variation. Wright's Fst was 0.17 for all four populations and 0.13 for the three Swedish populations. These relatively low values indicate that there is gene flow among all populations or that they are derived from a common ancestral population. The observed pattern of genetic variation is probably the result of effective spore dispersal and the continuous distribution of this common early successional species.

ABSTRACTHigh-throughput transcriptomics was used to identifyFibroporia radiculosagenes that were differentially regulated during colonization of wood treated with a copper-based preservative. The transcriptome was profiled at two time points while the fungus was growing on wood treated with micronized copper quat (MCQ). A total of 917 transcripts were differentially expressed. Fifty-eight of these genes were more highly expressed when the MCQ was protecting the wood from strength loss and had putative functions related to oxalate production/degradation, laccase activity, quinone biosynthesis, pectin degradation, ATP production, cytochrome P450 activity, signal transduction, and transcriptional regulation. Sixty-one genes were more highly expressed when the MCQ lost its effectiveness (>50% strength loss) and had functions related to oxalate degradation; cytochrome P450 activity; H2O2production and degradation; degradation of cellulose, hemicellulose, and pectin; hexose transport; ...