Degradation of lignin and lignin model compounds by various mutants of the white-rot fungusSporotrichum pulverulentum

✍ Scribed by Karl-Erik Eriksson; Susanna C. Johnsrud; Lars Vallander

• Publisher: Springer
• Year: 1983
• Tongue: English
• Weight: 818 KB
• Volume: 135
• Category: Article
• ISSN: 0302-8933
• DOI: 10.1007/bf00414473

✦ Synopsis

In order to better understand which enzyme are of importance in lignin degradation, new cellulase deficient strains from Sporotrichum puIverulentum have been isolated by spontaneous and induced mutations from both wild type and from the earlier studied cellulase deficient strain 44. These new strains are xylanase positive (Xyl+), and produce considerably higher amounts of phenol oxidases (Pox) than either parent type. The new strains have been compared with the wild type and strain 44 with respect to their ability to release 14C02 from a) vanillic acid labelled in the carboxyl, methoxyl and ring carbons; b) the dimer (4-methoxyJ4C)-veratrylglycerol-/?-guaiacyl ether; c) ~4C-ring-labelled DHP and 14C[/%carbon side chain] labelled DHP.

The new strains, the wild type and strain 44 were compared with respect to their ability to cause weight losses in wood blocks and to delignify wood. One of the new strains, 63-2, caused a higher weight loss in wood than either the wild type or strain 44. Another strain, 44-2, produced a higher weight loss than strain 44. An increase in acid-soluble lignin was observed in wood blocks treated for two weeks with the two new mutant strains and wild type. After prolonged incubation for 6 and 8 weeks the amount of acid-soluble lignin decreased.