Irradiation of Sound Waves to Aspergillus Kawachii and the Characterization of Enzyme Activities in Rice-Koji

Taku Matsumoto; Kouji Kojima; Noriaki Saigusa; Yuji Teramoto

Authors

Taku Matsumoto Department of Applied Microbial Technology, Faculty of Biotechnology and Life Science, Sojo University, 4-22-1 Ikeda, Nishi-Ward, Kumamoto 860-0082, Japan Author
Kouji Kojima Department of Applied Microbial Technology, Faculty of Biotechnology and Life Science, Sojo University, 4-22-1 Ikeda, Nishi-Ward, Kumamoto 860-0082, Japan. Author
Noriaki Saigusa Department of Applied Microbial Technology, Faculty of Biotechnology and Life Science, Sojo University, 4-22-1 Ikeda, Nishi-Ward, Kumamoto 860-0082, Japan. Author
Yuji Teramoto Department of Applied Microbial Technology, Faculty of Biotechnology and Life Science, Sojo University, 4-22-1 Ikeda, Nishi-Ward, Kumamoto 860-0082, Japan Author

Keywords:

Aspergillus kawachii, rice-koji, sound wave, glucoamylase, acid protease

Abstract

Conidiospores of A. kawachii were irradiated with sound waves at three different frequencies, 1.0, 6.3, and 16.0 kHz, with a constant sound pressure of 5.0 dB. Steamed rice was inoculated with the resulting conidiospores and incubated at 25°C for 30 h to make rice-koji. By irradiation with sound waves at 6.3 kHz to conidiospores of A. kawachii, the activities of glucoamylase and acid protease of rice-koji were increased by 1.33 and 1.37 times, respectively, over that of rice-koji prepared without sound wave irradiation. The amount of mycelium in rice-koji prepared with conidiospores treated by sound wave irradiation at 6.3 kHz was also 1.31 times higher than that prepared without sound wave irradiation. To confirm the usefulness of sound wave irradiation as a condition for making rice-koji, the effects of sound waves on enzyme activities and mycelium weight of rice-koji produced by sound-treated conidiospores of A. kawachii were investigated.