Abstract
Each of ten isolates of Botrytis cinerea used in this study produced three kinds of macerating activities, which have been designated in this paper as M-I, M-II, and M-III. M-I and M-II were active on potato tubers and had respective pH optima at about 2.7 and 5.5. M-III, having a pH optimum near 4.5, degraded mitsumata inner barks but did not macerate potato tubers.
Production of three macerating activities was found to be constitutive throughout all growth phases of mycelia. on cultures with some isolates, M-II ahd M-III disappeared when pH of the culture solution decreased to 2.5. This was attributed to inactivation of M-II and M-III at low pH.
Isolate R-2, the most potent producer of macerating enzymes among the isolates used, produced on peptone-salts solutions a pectin esterase (opt. pH 5.0), endo-polymethyl-galacturonases (opt. pH 3.5 and 4.3), endo-polygalacturonases (opt. pH 4.3 and 5.5), exo-polygaiacturonases (opt. pH 4.3 and 5.5), and cellulases Cx (opt. pH 4.5 and 6.5). No trans-eliminase activity for pectin and pectic acid was detected in cultures on the solution either with or without pectin.
Zone electrophoretic study indicated that M-I and M-II were composed of three and two components, respectively.
A qualitative comparison of macerating and related enzyme activities described in the literature and in the present study was made.
