Department of Biological and Pharmaceutical Engineering Ningbo Institute of Technology Zhejiang University Ningbo 315100 China;
Institute of Bioengineering College of Materials Science and Chemical Engineering Zhejiang University Hangzhou 310027 Ch;
Institute of Bioengineering College of Materials Science and Chemical Engineering Zhejiang University Hangzhou 310027 China;
Spiramycin; Streptomyces ambofaciens; Strain improvement; Fermentation;