1. Department of Applied Biology, Faculty of Textile Science and Technology, Shinshu University, 3-15-1 Tokida, Ueda 386-8567, Japan
2. Division of Biological and Medical Fibers, Interdisciplinary Cluster for Cutting Edge Research, Institute for Fiber Engineering, Shinshu University, 3-15-1, Tokida, Ueda City, Nagano 386-8567, Japan