1. Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo 060-8628, Japan
2. Bioproducts Research Group, Biotechnology Research Laboratories, Kaneka, Takasago 676-8688, Japan
3. Polymer Fundamental Research Team, BDP Technology Laboratories, Kaneka, Takasago 676-8688, Japan
4. Division of Applied Chemistry, Faculty of Engineering, Hokkaido University, Sapporo 060-8628, Japan