<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Farnet, A M</style></author><author><style face="normal" font="default" size="100%">Criquet, S</style></author><author><style face="normal" font="default" size="100%">Pocachard, E</style></author><author><style face="normal" font="default" size="100%">Gil, G</style></author><author><style face="normal" font="default" size="100%">Ferré, E</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Purification of a new isoform of laccase from a Marasmius quercophilus strain isolated from a cork oak litter (Quercus suber L.)</style></title><secondary-title><style face="normal" font="default" size="100%">MYCOLOGIA</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">aromatic compounds</style></keyword><keyword><style  face="normal" font="default" size="100%">mediator</style></keyword><keyword><style  face="normal" font="default" size="100%">polyphenoloxidase</style></keyword><keyword><style  face="normal" font="default" size="100%">white-rot fungus</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2002</style></year></dates><publisher><style face="normal" font="default" size="100%">NEW YORK BOTANICAL GARDEN</style></publisher><pub-location><style face="normal" font="default" size="100%">PUBLICATIONS DEPT, BRONX, NY 10458 USA</style></pub-location><volume><style face="normal" font="default" size="100%">94</style></volume><pages><style face="normal" font="default" size="100%">735-740</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">A new isoform of laccase from Marasmius quercophilus is described in this study. The strain of this white-rot fungus was isolated for the first time on a cork oak litter. This isoform exhibited certain common properties of laccases (a molecular weight of 65 Kda, an optimum pH of 6.2 with syringaldazine). But this laccase has also particularly novel features: the best activity measured was observed at high temperatures (80 C) and this isoform was not inhibited with EDTA. Furthermore, this induced laccase was able to transform most of the aromatic compounds tested without the addition of mediators to the reaction mixture, and the transformation of certain chlorophenols (2-chlorophenol and 2,4-dichlorophenol) by a laccase isoform from M. quercophilus is reported here for the first time. We also demonstrate the importance of 2,2'-azinobis(3-ethylbenzthiazoline-6-sulfonate) (ABTS) as a mediator since it allowed veratryl alcohol and p-hydroxybenzoic acid transformation. Moreover, new products of transformation were observed using the combination of ABTS with this isoform of laccase.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Dedeyan, B</style></author><author><style face="normal" font="default" size="100%">Klonowska, A</style></author><author><style face="normal" font="default" size="100%">Tagger, S</style></author><author><style face="normal" font="default" size="100%">Tron, T</style></author><author><style face="normal" font="default" size="100%">Iacazio, G</style></author><author><style face="normal" font="default" size="100%">Gil, G</style></author><author><style face="normal" font="default" size="100%">Le petit, J</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Biochemical and molecular characterization of a laccase from Marasmius quercophilus</style></title><secondary-title><style face="normal" font="default" size="100%">APPLIED AND ENVIRONMENTAL MICROBIOLOGY</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Basidiomycete</style></keyword><keyword><style  face="normal" font="default" size="100%">litter</style></keyword><keyword><style  face="normal" font="default" size="100%">Marasmius quercophilus</style></keyword><keyword><style  face="normal" font="default" size="100%">mediterranean forest</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex L.</style></keyword><keyword><style  face="normal" font="default" size="100%">structural genes</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2000</style></year></dates><publisher><style face="normal" font="default" size="100%">AMER SOC MICROBIOLOGY</style></publisher><pub-location><style face="normal" font="default" size="100%">1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 USA</style></pub-location><volume><style face="normal" font="default" size="100%">66</style></volume><pages><style face="normal" font="default" size="100%">925-929</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The basidiomycete Marasmius quercophilus is commonly found during autumn on the decaying litter of the evergreen oak (Quercus ilex L.), a plant characteristic of Mediterranean forest. This white-rot fungus colonizes the leaf surface with rhizomorphs, causing a total bleaching of the leaf. In synthetic liquid media, this white-rot fungus has strong laccase activity. From a three-step chromatographic procedure, we purified a major isoform to homogeneity, The gene encodes a monomeric glycoprotein of approximately 63 kDa, with a 3.6 isoelectric point, that contains 12% carbohydrate, Spectroscopic analysis of the purified enzyme (UV/visible and electron paramagnetic resonance, atomic absorption) confirmed that it belongs to the ``blue copper oxidase{''} family. With syringaldazine as the substrate, the enzyme's pH optimum was 4.5, the optimal temperature was 75 degrees C, and the K-m was 7.1 mu M. The structural gene, lac1, was cloned and sequenced. This gene encodes a 517-amino-acid protein 99% identical to a laccase produced by PM1, an unidentified basidiomycete previously isolated from wastewater from a paper factory in Spain. This similarity may be explained by the ecological distribution of the evergreen oak in Mediterranean forest.</style></abstract><notes><style face="normal" font="default" size="100%">Keys: APS</style></notes><research-notes><style face="normal" font="default" size="100%">Keys: APS</style></research-notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Tagger, S</style></author><author><style face="normal" font="default" size="100%">Périssol, C</style></author><author><style face="normal" font="default" size="100%">Gil, G</style></author><author><style face="normal" font="default" size="100%">Vogt, G</style></author><author><style face="normal" font="default" size="100%">Le petit, J</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Phenoloxidases of the white-rot fungus Marasmius quercophilus isolated from an evergreen oak litter (Quercus ilex L.)</style></title><secondary-title><style face="normal" font="default" size="100%">Enzyme and Microbial Technology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">aromatic compounds</style></keyword><keyword><style  face="normal" font="default" size="100%">kraft pulp</style></keyword><keyword><style  face="normal" font="default" size="100%">laccases</style></keyword><keyword><style  face="normal" font="default" size="100%">Lignin</style></keyword><keyword><style  face="normal" font="default" size="100%">Marasmius quercophilus</style></keyword><keyword><style  face="normal" font="default" size="100%">phenoloxidases</style></keyword><keyword><style  face="normal" font="default" size="100%">tannin monomers</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1998</style></year></dates><volume><style face="normal" font="default" size="100%">23</style></volume><pages><style face="normal" font="default" size="100%">372-379</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">A white-rot basidiomycete, Marasmius quercophilus, was isolated from an evergreen oak litter. This fungus, which very thoroughly bleaches the whole leaf area, produces laccases, a property which has not been studied before. Except on a ground leaf medium, we did not reveal phenoloxidases other than laccases. M. quercophilus is able to transform many aromatic compounds which are by-products of lignin and tannin metabolism. We observed, for example, that lignin monomers, namely p-coumaryl, coniferyl, and sinapyl alcohols are oxidized at different rates by the extracellular crude enzyme extract. The highest production of laccases is obtained with shaking cultures on malt extract supplemented with Tween 80 (0.1%) and CuSO4 (0.5 mg l 21 ). These enzymes have an optimum activity at 80°C and a stable activity at 40°C for 18 h. The extracellular crude enzyme extract medium contains three isoenzymes with pI values of 3.8, 3.5, and 3.2. It is able to significantly reduce the kappa number (21.2%) of a kraft pulp without inclusion of any mediator</style></abstract></record></records></xml>