A Method of Enhancing the Glucoamylase Activity and the Germination Ratio of Rice-Koji via Exposure to Sound Waves

Taku Matsumoto; Kouji Kojima; Noriaki Saigusa; Yuji Teramoto

Authors

Taku Matsumoto Department of Applied Microbial Technology, Faculty of Biotechnology and Life Science, Sojo University, Japan Author
Kouji Kojima Department of Applied Microbial Technology, Faculty of Biotechnology and Life Science, Sojo University, Japan Author
Noriaki Saigusa Department of Applied Microbial Technology, Faculty of Biotechnology and Life Science, Sojo University, Japan Author
Yuji Teramoto Department of Applied Microbial Technology, Faculty of Biotechnology and Life Science, Sojo University, Japan Author

Keywords:

aspergillus oryzae RIB40, rice-koji, glucoamylase activity, sound waves

Abstract

Research has shown that sound can influence microorganisms’ growth and enzymatic activity. In this study, the glucoamylase activity of rice-koji was decreased when conidiospores of Aspergillus oryzae were exposed to sound irradiation during incubation. While this indicates an indirect effect of sound on glucoamylase activity, the possibility of a direct influence remains unclear. To explore this, rice-koji was prepared with direct sound irradiation at a sound pressure of 5.0 dB for 24 hours during the early stages of production. Results indicated a 1.3-fold increase in glucoamylase activity after incubation, with no change in hyphal weight. Sound waves at 16 kHz were also observed to enhance the germination ratio.