1. Department of Microbiology and Institute for Basic Science, Chungbuk National University, Cheongju 361-763, Chungbuk, Republic of Korea
2. Department of Biological Sciences, Korea Advanced Institute of Science and Technology, 373-1, Guseong-dong, Yuseong-gu, Daejeon 305-701, Republic of Korea
3. School of Electrical and Computer Engineering, Chungbuk National University, Cheongju 361-763, Chungbuk, Republic of Korea
4. Department of Agricultural Chemistry, Kyungpook National University, Daegu 702-701, Republic of Korea