Induction of Cellulases in chaetomium cellulolyticum by cellobiose

Abstract

The production of extracellular cellulases by Chaetomium cellulolyticum could be induced by slow feeding of cellobiose to the cultures. Both the rate of production and the amount of activity were comparable to that obtained in batch cultivation on cellulose. The specific filter paper activity of 2.06 U per mg protein was almost two times higher than that obtained in cellulose medium. Cellulases were not induced when glucose was slowly fed to the cultures. Changing the feed stream from glucose to cellobiose resulted in a rapid accumulation of cellulases. Thus cellobiose has a similar role in cellulase induction in C. cellulolyticum, as earlier shown for Trichoderma reesei.

Polymerisation of lignins by ligninases fromPhanerochaete chrysosporium

“…">INTRODUCTIONLignin, a complex and heterogeneous aromatic biopolymer and one of the major components of wood [1], can be degraded by some microorganisms, of which the basidiomycete P. chrysosporium is presently the best characterised [2]. This fungus produces several extracellular peroxidases (ligninases) [3][4][5][6][7] which catalyse 1-electron oxidations in various lignin-related and other aromatic compounds [3][4][5][6][7][8][9][10]. Some lignin-degrading activity has been reported for one of the enzymes [3], which seem to be an important part of the ligninolytic system of P. chrysosporium [11].…”

“…">Protein production and purificationP. chrysosporium (ATCC24725) was grown in C-limited cultures [5], which were inoculated with spore suspension and grown on a rotary shaker (150 rev./min, 2.5 cm) in 1-1 Erlenmeyer flasks (0.6 1 medium) for 48 h in air at 37°C. The fungal biomass (in pellet form) was then concentrated 4-fold by decanting excess medium and veratryl alcohol was added to a final concentration of 1.5 mM.…”

The biosynthesis of shikimate metabolites

“…The formation of (-)-epicatechin in Nature from (+)dihydroquercetin (8 1) necessitates inversion of stereochemistry at C-3, and various suggestions have been put forward to account for this feature. These include the action of a C-3 epimerase on (81), the intermediacy of flav-3-en-3-01 and carbocation derivatives, or the involvement of a-hydroxychalcones. Based on chemical reactions, a revised sequence has been proposed.…”