Cell Wall Alterations Associated with the Hyperproduction of Extracellular Enzymes in Neurospora crassa

A pleiotropic mutation in Neurospora (exo-1), which confers derepression of alpha-amylase, glucoamylase, beta-fructofuranosidase, and trehalase, appears to also affect the composition of the cell wall. Segregants resulting from the backcross of exo-1 to the wild-type strain from which it derived are altered in the ratio of galactosamine to glucosamine in hydrolysates of isolated cell walls. Conidial cell walls exhibit a marked decrease in the amount of galactosamine in both exo-1 and exo-1(+) strains. Increased levels (approximately sevenfold) of amylase are found in conidia of exo-1, as compared with those of exo-1(+).