1. Japan Collection of Micro‐organisms, The Institute of Physical and Chemical Research, Saitama,
2. National Institute of Animal Industry, Tsukuba Norin Kenkyu Danchi, Tsukuba, Ibaraki‐ken,
3. National Grassland Research Institute, Tochigi‐ken,
4. College of Agriculture, Ehime University, Matsuyama, Ehime‐ken, Japan