Study On Biosynthesis Of Spiramycin And Effective Components Optimization

In this thesis, the fermentation process of Streptomyces spiramyceticus was explored in order to improve the production of spiramycin.Different vegetable oils had different effects on the production of spiramycin and soybean oil 4 was the best. The content of fatty acids in vegetable oils was determined by GC-MS. Thus, various fatty acids were also studied and the significant differences were found on the production of spiramycin. Linoleic acid was the most useful for biosynthesis of spiramycin among various fatty acids. After that, the experiments were carried out by combining fatty acids in different propotion and also performed by combining fatty acids in different propotion without a specific fatty acid. The optimal propotion of fatty acids was "stearic acid 4.5%, palmitic acid 13.5%, linoleic acid 63.0%, oleic acid 9.0%, glycerol 10.0%", which was benefical to industry production.Met restricts the spiramycin biosynthesis. However, Trp and Asn can enhance its production to some extent. The production of spiramycin could be increased by 9.93% when Trp was added at 0.025 g/L and 12 h. The optimal concentration and adding time of Asn were 0.1 g/L and 0 h. Under such condition, the production of spiramycin was increased by 16.15% and the percentage of spiramycin I was controlled below 12%.Mn2+ has little effects on the production of spiramycin. But it can improve spiramycin components to some extent. When Al3+ was added at 0.32 g/L and 0 h, the production of spiramycin could be enhanced 10.86%.Studys on 15 L fermentor showed that the production of spiramycin and components made differences when Al3+ was added at different time. The optimal adding time was 12 h. Under this condition, the production of spiramycin and the percentage of spiramycin I could be enhanced and decreased 19.51% and 72.75% respectively. In addition, fermentation process could be regulated and controlled easily.