1. National Agriculture and Food Research Organization, National Institute of Livestock and Grassland Science, Nasushiobara, Tochigi 329-2793, Japan
2. Japan Collection of Microorganisms, RIKEN BioResource Center, Tsukuba, Ibaraki 305-0074, Japan
3. National Agriculture and Food Research Organization, National Institute of Livestock and Grassland Science, Tsukuba, Ibaraki 305-0901, Japan