Most flamentous fungi appear to be poor producers of amethylglucuronidases.
Ishihara and Shimizu (1988) systematically screened aglucuronidase-producing
fungi in order to identify other enzymes. Of nine
Trichoderma and five basidiomycete species (including a strain of A. bisporus),
Tyromyces palustris was the best producer. Concentrated protein precipitates
from cell broths were screened against a model substrate of 2-O-(4-O-methyla-D-glucuronopyranose)-D-mxylitol.
This enabled the detection of reducing
group production against a very low background. Even though T. palustris
produced more a-glucuronidase than did other fungi, total activity amounted
to < 0.1 unit/ml. Moreover, the activity was very labile, even in frozen storage.
Streptomyces flavogriesus and S. olivochromogenes also formed a-Omethylglucuronidase
at low titers (MacKenzie et al. 1987; Johnson et al. 1988).