Abstract
Mushrooms producing salt-tolerant proteases were screened for use in the production of fermented foods under high NaCl concentrations. Of 35 strains of mushrooms tested on solid-state culture with wheat bran, 13 showed high protease activity. The effect of NaCl concentration used in miso brewing on protease activity was investigated in these 13 strains. Seven strains exhibiting more than 35% relative residual activity under 10% NaCl were selected. These strains seemed to be suitable for use in miso production. The seven strains were examined for salt-tolerance under 18% NaCl. Relative residual activity of three strains was more than 10% under 18% NaCl. Among the three strains, Ganoderma lucidum YFH 05001 was shown to be the most salt-tolerant strain, showing 13.7% relative activity. Salt-tolerance of this strain was better than that of the commercial Aspergillus oryzae strain used in soy sauce brewing.
