1. Division of Microbiology, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501, Japan, School of Bioresources, Hiroshima Prefectural University, 562 Nanatsuka, Shobara-shi, Hiroshima 727-0023, Japan, NF Division Research & Development, Taiyo Kagaku Co., Ltd., Yokkaichi, Mie 510-0825, Japan, and Department of Hygienic Chemistry, Osaka University of Pharmaceutical Sciences, 4-20-1 Nasahara, Takatsuki, Osaka 569-1094, Japan