| abstract |
PROBLEM TO BE SOLVED: To provide an excellent cationic polymer having high safety and biodegradability, and a method for producing the same. The ε-polylysine produced by microbial fermentation is heat-treated at a temperature of 150 ° C. or higher in an atmosphere of inert gas or vacuum to increase the viscosity of a 15% by weight aqueous solution to 6 mPa · sec or higher. To 10. 0 or more. Polylysine still having a molecular weight of 30,000 or more as measured by SDS-PAGE. |