DEGRADATION OF STRUCTURAL POLYSACCHARIDES BY THE PLANT CELL-WALL DEGRADING ENZYME-SYSTEM FROM ANAEROBIC FUNGI - AN APPLICATION STUDY

The degradation capacity of extracellular enzyme preparations from two anaerobic fungi, i.e., Piromyces sp. strain E2 and Neocallimastix pat riciarum strain N2, toward several types of lignocellulosic substrates was studied. The enzymes were capable of effectively converting up to 2% (w/v) microcrystalline cellulose (Avicel) to glucose, thereby indi cating the presence of all catalytic activities (endoglucanases, exogl ucanases, and beta-glucosidases) needed. Performance of these enzymes surpassed that of a combined preparation of the commercial enzymes Cel luclast and Novozym in batch degradation of 2% (w/v) Avicel. The enzym es from anaerobic fungi are very stable at 40 degrees C. After one wee k of incubation at this temperature in the absence of substrate, about 50% of activity towards Avicel was retained. Although the performance of the enzyme system was lowered when increasing initial glucose conc entrations were applied, still over 30% of sugar release was observed at an initial monomer concentration of 200 mM. Various natural lignoce llulosic materials were ground and tested as substrates. A negative co rrelation was found between the amount of lignin in the substrate and the release of soluble sugars. (C) 1997 Elsevier Science Inc.