Chemical compositions of the hyphal walls of three chromomycosis agents

Chemical analyses demonstrated the similar compositions of hyphal walls isolated from the chromomycosis agents Phialophora verrucosa, P. pedrosoi and Cladosporium carrionii. Unfractionated walls of each species consisted of large amounts of glucose (17-31%) and protein components (29-42%) and smaller amounts of mannose (8-14%) and glucosamine (6-8%). Alkali-soluble wall fractions consisted predominantly of glucose and mannose, while alkali-insoluble wall fractions consisted predominately of glucosamine and protein components. Chitin was identified as a wall component by release of N-acetylglucosamine during enzymatic digestions of the walls with Streptomyces griseus chitinase. The presence of chitin in the walls and alkali-insoluble residues was confirmed by X-ray powder analysis. The suggestion is made that the hyphal forms of human pathogenic fungi have wall compositions intermediate between those of euascomycetes and hemiascomycetes.