1. Research and Development Division, Kikkoman Corporation, 399 Noda, Noda City, Chiba 278-0039, Japan
2. Hashima Laboratory, Nihon Bioresearch Inc., 6-104 Majima, Fukuju-cho, Hashima, Gifu 501-6251, Japan
3. Nippon Del Monte Corporation, 3748 Shimizu-cho, Numata, Gunma 378-0016, Japan
4. Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan