Open AccessProgress in biopulping of non‐woody materials: Chemical, enzymatic and ultrastructural aspects of wheat straw delignification with ligninolytic fungi from the genus Pleurotus
Author(s) -
Martínez Angel T.,
Camarero Susana,
Guillén Francisco,
Gutiérrez Ana,
Muñoz Carmen,
Varela Elisa,
Martínez Maria J.,
Barrasa JoséM.,
Ruel Katia,
Pelayo JoséM.
Publication year - 1994
Publication title -
fems microbiology reviews
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.91
H-Index - 212
eISSN - 1574-6976
pISSN - 0168-6445
DOI - 10.1111/j.1574-6976.1994.tb00047.x
Subject(s) - lignin , pleurotus eryngii , laccase , phanerochaete , straw , pleurotus , cellulose , middle lamella , lignin peroxidase , chemistry , solid state fermentation , steam explosion , food science , polyphenol oxidase , botany , peroxidase , fermentation , biology , mushroom , biochemistry , organic chemistry , enzyme , pulp and paper industry , inorganic chemistry , engineering
During screening of basidiomycetes for wheat straw delignification, considerable lignin degradation with a limited attack to cellulose was attained with Pleurotus eryngii . Straw solid‐state fermentation (SSF) was optimized, and the enzymatic mechanisms for lignin degradation were investigated. No lignin peroxidase was detected under liquid or SSF conditions, but high laccase and aryl‐alcohol oxidase levels were found. The latter enzyme has been fully characterized in PI. eryngii and it seems to be involved in a cyclic redox system for H 2 0 2 generation from aromatic compounds. Results obtained using homoveratric acid suggest that Pleurotus laccase could be involved in degradation of phenolic and non‐phenolic lignin moieties. Histological and ultrastructural studies provided some general morphological characteristics of the fungal attack on wheat straw. Whereas a simultaneous degradation pattern was observed in straw treated with Phanerochaete chrysosporium , PI. eryngii caused partial degradation of middle lamella and separation of individual sclerenchymatic fibers. When these straw samples were subjected to refining tests, energy saving after biological treatment was the highest in the case of straw treated with PI. eryngii , which also produced the lowest substrate loss. From these results, a correlation between preferential removal of lignin, separation of sclerenchymatic fibers and pulping properties was provided during fungal treatment of wheat straw.