Продуцирование ненасыщенных жирных кислот в течение деревразрушения базидиомицетами
22.12.2010 01:29 Обновлено 18.05.2011 20:42
Production of New Unsaturated Lipids during Wood Decay by
Ligninolytic Basidiomycetes
Ana Gutiérrez,1 José C. del Rı´o,1 Marı´a J. Martı´nez-I´n˜igo, Marı´a J. Martı´nez, and Ángel T. Martı´nez
Lipids were analyzed by gas chromatography-mass spectrometry for a 7-week in vitro decay of eucalypt wood
by four ligninolytic basidiomycetes. The sound wood contained up to 75 mg of lipophilic compounds per 100
g of wood. Hydrolysis of sterol esters, which represented 38% of total wood lipids, occurred during the fungal
decay. The initial increase of linoleic and other free unsaturated fatty acids paralleled the decrease of sterol
esters. Moreover, new lipid compounds were found at advanced stages of wood decay that were identified from
their mass spectra as unsaturated dicarboxylic acids consisting of a long aliphatic chain attached to the C-3
position of itaconic acid. These dicarboxylic acids were especially abundant in the wood treated with Ceriporiopsis
subvermispora (up to 24 mg per 100 g of wood) but also were produced by Phlebia radiata, Pleurotus
pulmonarius, and Bjerkandera adusta. We hypothesize that three main alkylitaconic acids (tetradecylitaconic,
cis-7-hexadecenylitaconic, and hexadecylitaconic acids) are synthesized by fungi in condensation reactions
involving palmitic, oleic, and stearic acids. We suggest that both wood unsaturated fatty acids (present in free
form or released from esters during natural decay) and unsaturated metabolites synthesized by fungi could
serve as a source for peroxidizable lipids in lignin degradation by white rot basidiomycetes.