1. Laboratory of Applied Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Science, Tohoku University, 1-1 Tsutsumi-dori, Amamiya-machi, Aoba-ku, Sendai 981-8555
2. Department of Human Health and Nutrition, Graduate School of Comprehensive Human Sciences, Shokei Gakuin University, Yurigaoka 4-10-1, Natori 981-1295, Japan