Detection of beta-galactofuranosidase production by Penicillium and Aspergillus species using 4-nitrophenyl beta-D-galactofuranoside.

An assay was developed for detecting beta-galactofuranosidase produced by Penicillium and Aspergillus spp. The substrate for the assay, 4-nitrophenyl beta-D-galactofuranoside, was synthesized from penta-O-acetyl-beta-D-galactofuranose and 4-nitrophenol by a tin chloride catalyzed reaction followed by O-deacetylation. Aspergillus spp. produced only small quantities of beta-galactofuranosidase during 30 d at 25 degrees C. Only the biverticillate Penicillium spp. (P. funiculosum, P. islandicum, P. rubrum and P. tardum) produced substantial beta-galactofuranosidase after 1-4 weeks at 25 degrees C. No extracellular antigens of these four Penicillium spp. could be detected in culture filtrates by the sandwich ELISA technique when antibodies to the extracellular beta-galactofuranoside-containing polysaccharide antigen of P. digitatum was used. Antigens to all other Penicillium and Aspergillus spp. were easily detected in their culture filtrates.