DETECTION OF 9 CHITINASE SPECIES IN GERMINATING CELLS OF MUCOR-ROUXII

Chitinolytic activity in aerobically germinating cells of Mucor rouxii was studied. When an ammonium sulfate fraction (40% saturation) of cytosol was subjected to column chromatography in Bio-Gel P-100, two peaks of activity were separated: A and B, which showed molecular weights of 53 KDa and 28 KDa, respectively. After further purification by ion exchange chromatography in a column of DEAE Bio-Gel A, the lytic activity from peaks A and B resolved into four and five species, respectively. Species from peak A eluted with peaks at 0.075, 0.125, 0.160, and 0.225 M NaCl, whereas those from peak B did so at 0.050, 0.125, 0.190, 0.240. and 0.300 M NaCl. Like other chitinases from the same fungus, the ones detected here are of the exochitinolytic type, releasing diacetylchitobiose units from nascent chitin chains. The complex chitinolytic system in these cells is discussed and compared with that exhibited by exponentially growing cells of the same fungus. © 1991 Springer-Verlag New York Inc.