1Department of Biotechnology, University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113, Japan
2Institute for Fundamental Research, Suntory Limited, Wakayamadai 1-1-1, Shimamoto-cho, Mishima-gun, Osaka 618, Japan
3Department of Applied Biological Resource Science, Ibaraki University, Ami-machi, Ibaraki 300-03, Japan
4Faculty of Textile Science and Technology, Shinshu University, Tokida 3-15-1, Ueda, Nagano 386, Japan