1. Department of Environmental Systems Engineering, Nagaoka University of Technology, Nagaoka, Niigata 940-2188, Japan
2. Subground Animalcule Retrieval Program, Extremobiosphere Research Center, Japan Agency for Marine-Earth Science & Technology, Yokosuka, Kanagawa 237-0061, Japan
3. Department of Social and Environmental Engineering, Hiroshima University, Higashi-Hiroshima 739-8527, Japan
4. Department of Civil Engineering, Tohoku University, Sendai, Miyagi 980-8579, Japan