*Yuichi Nishimura¹, Purna Sulastya Putra², Septriono Hari Nugroho², Eko Yulianto², Takashi Chiba³ (1.Graduate School of Science, Hokkaido University, 2.Research Center for Geotechnology, Indonesian Institute of Sciences (LIPI), 3.Faculty of Bioresource Sciences, Akita Prefectural University)