Significant alterations of the culture were observed: (a) the medium became increasingly opalescent due to the secretion of a protein aggregate (PA) which contained 15% neutral sugar, mainly ribose; (b) the peptidophosphogalactomannan (pPGM) containing galactofuranose, normally produced by P. fellutanum, could not be obtained from the culture medium in the presence of the inhibitors; (c) the content of galactofuranose in the cell wall was significantly decreased in the presence of D-galactono-1,4-lactone.