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Two ustilaginomycetous anamorphic strains were isolated from flowers in Taiwan. Phylogenetic analysis based on the combined rRNA gene sequence of internal transcribed spacer 1 (ITS1)-5.8S-ITS2 and large-subunit D1/D2 domains indicated that the closest recognized species was Pseudozyma fusiformata. The results of DNA-DNA hybridization and physiological characteristics showed that the two strains represent a novel species within the genus Pseudozyma. The name Pseudozyma pruni sp. nov. is proposed, with FIRDI 005 T (5BCRC 34227 T 5CBS 10937 T ) as the type strain.

The isoamylase activity of Pseudomonas amyloderamosa WU 5315 was stable over the pH range from 5.5 to 6.25 while only about 30% of the activity remained at pH 6.5. Low isoamylase activity (418 U ml‐1) was produced by the cells grown at high pH. Activity reached almost 3000 U ml‐1 when pH was kept below 6.0 during the fermentation. With 1% glucose plus 2% maltose instead of 3% maltose as carbon source, however, no pH control was required and the isoamylase activity of Ps. amyloderamosa WU 5315 increased to 3400 U ml‐1.

Culture filtrates of 22 mushrooms were screened for extracellular prolyl oligopeptidase activity. Four strains with relatively high enzyme activity were all from inky cap mushrooms. The production of Coprinopsis clastophylla prolyl oligopeptidase was associated with the growth of the fungus and the enzyme was not released by cell lysis. The enzyme was purified 285-fold to a specific activity of 52.05 U/mg. It was purified to a single band on a native polyacrylamide gel. However, the enzyme separated into three bands on a sodium dodecyl sulfate-polyacrylamide gel with mobility corresponding to molecular weights of approximately 84, 60, and 26 kDa. The results of tandem mass spectrometric analysis revealed that the 60 kDa protein was likely a degradation product of the 84 kDa protein. The isoelectric point of the purified enzyme was 5.2. The purified enzyme had an optimal pH and temperature of 8.0 and 37°C, respectively. Diisopropyl fluorophosphate (DFP), p-chloromercuribenzoaic acid (PCMB), Hg(2+), and Cu(2+) strongly inhibited C. clastophylla prolyl oligopeptidase. This enzyme is a serine peptidase and one or more cysteine residues of the enzyme are close to the active site.