1. Department of Life Science, College of Science; Rikkyo University; 3-34-1 Nishi-Ikebukuro, Toshima-ku Tokyo 171-8501 Japan
2. Microbial Genetics Laboratory, Genetic Strains Research Center; National Institute of Genetics; 1111 Yata Mishima Shizuoka 411-8540 Japan
3. Department of Genetics; The Graduate University for Advanced Studies, Sokendai; 1111 Yata Mishima Shizuoka 411-8540 Japan