The Brown-Rot Basidiomycete Fomitopsis palustris Has the Endo-GlucanasesCapable of Degrading Microcrystalline Cellulose

Two endoglucanases with processive celulaseactivities, produced from Fomitopsis palustrismicrocrystalline cellulose (Avicel), were purified to homogeneityby anion-exchange and gel filtration column chromatographysystems. SDS-PAGE analysis indicated that the molecularmases of the purified enzymes were 47 kDa and 35 kDa,respectively. The amino acid sequence analysis of the 47-kDaprotein (EG47) showed a sequence similarity with fungalglycoside hydrolase family 5 endoglucanase from the white-rot fungus Phanerochaete chrysosporium. N-terminal andhowever, had no homology with any other glycosylhydrolases,although the enzyme had high specific activity againstcarboxymethyl cellulose, which is a typical substrate forendoglucanases. The initial rate of Avicel hydrolysis by EG35was relatively fast for 48 h, and the amount of soluble reducingsugar released after 96 h was 100g/ml. Although EG47also hydrolyzed Avicel, the hydrolysis rate was lower thanthat of EG35. Thin layer chromatography analysis of thehydrolysis products released from Avicel indicated that thefungus possesses processive EGs capable of degradingcrystalline cellulose. KCI Citation Count: 22