REGULATION OF PROTEIN SECRETION BY MYCELIAL CULTURE OF THE MUSHROOM TERMITOMYCES-CLYPEATUS

Termitomyces clypeatus secreted a 24-kDa xylanase constitutively in xy lan medium, bur required a gluconeogenic amino acid or Krebs cycle aci d for the secretion of a 56-kDa amyloglucosidase in dextrin medium. As partate, glutamate, succinate and fumarate all increased secretion of amyloglucosidase from 50% to > 90% and enzyme production by 10-fold wi th little effect on xylanase production. Glutamate or succinate stimul ated in vitro release of intracellular amyloglucosidase from washed my celia in the presence of cycloheximide. Amyloglucosidase accumulated i n the absence of glutamate was a high-molecular-mass protein that did not migrate in PAGE. Cellular regulation by the fungus of the secretio n of amyloglucosidase is indicated.