Matashi Kono

Productivity of hydrolytic enzymes by mycorrhizal mushrooms

To survey the potential for production of extracellular hydrolytic enzymes by mycorrhizal mushrooms, productivities of these exo-enzymes from mycelia on potato-dextrose liquid medium were determined.Tricholoma matsutake produced relatively high levels of CM-cellulase and avicelase activities in all test strains. It also produced higher activity of acid proteinase than neutral proteinase. Its xylanase activities seemed to be higher than those of the other carbohydrases. The productivities ofLyophyllum shimeji strains were at similar levels to those ofT. matsutake strains. CM-cellulase and avicelase activities ofL. shimeji were higher than those ofT. matsutake. Neutral proteinase inL. shimeji strains showed higher activity levels than acid proteinase. The relative productivities of hydrolytic enzymes between the groups of mycorrhizal mushrooms and wood-rotting mushrooms were also examined.T. matsutake andL. shimeji both produce many kinds of hydrolytic enzymes in their culture broth, and the potential for production of hydrolytic enzymes by mycorrhizal mushrooms was judged to be relatively high.

Purification and Some Properties of Carboxyl Proteinase in Extract from Lentinus edodes Fruit-bodies

To clarify the function of carboxyl proteinase inhibitor (S-PI, Pepstatin Ac) in the fruit-body formation of Basidiomycetes, we purified the carboxyl proteinase in the extract from Lentinus edodes fruit-bodies. About 70 mg of purified enzyme was obtained from 6 kg of wet fruit-bodies, with 20% recovery. The enzyme showed a single protein band on polyacrylamide gel electrophoresis.The molecular weight and isoelectric point were 42,000 and pH 4.5, respectively. The enzyme contained no arginine, and the contents of lysine and histidine residues were higher than those of other carboxyl proteinases in vegetative mycelium or culture filtrates. The enzyme was most active between pH 2.5 ~ 2.8, and stable over a range of pH 3.1 ~ 5.7 when incubated at 37°C, for 3 hr. The enzyme was inhibited by S-PI, DAN, and EPNP, which are specific inhibitors for carboxyl proteinases. The rate of inhibition by S-PI was very different from that in other carboxyl proteinases described above. The enzyme preferentially split the Leu...