PURIFICATION AND PROPERTIES OF THE XYLANASES FROM THE TERMITE MACROTERMES BELLICOSUS AND ITS SYMBIOTIC FUNGUS TERMITOMYCES SP

Four xylanases were purified, two from the termite Macrotermes bellico sus workers (X1T and X2T) and two from its symbiotic fungus Termitomyc es sp. (X1Mc and X2Mc). The analysis of the step required for the puri fication of X1T and X1Mc and the comparison of their different propert ies suggested that xylanases X1T and X1Mc were the same enzyme, X1. Th e determination of the reducing sugars by TLC revealed that X1 was an endoxylanase (EC 3.2.1.8) and X2T and X2Mc were exoxylanases (EC 3.2.1 .37). The apparent molecular weights of the three xylanases, determine d by SDS-polyacrylamide gel electrophoresis, were 36 kDa for X1, 56 kD a for X2T and 22.5 kDa for X2Mc. The optimal pH of the three xylanases was similar to 5.5, and K-m values determined with birchwood xylan as substrate were 0.2% for X1, 0.1% for X2T and 0.3% for X2Mc, showing a high affinity for this substrate. The three enzymes differed also by their thermal stability.