Study On Scale Up Of Nosiheptide Fermentation

Nosiheptide, produced by Streptomyces actuosus, is one of sulfur-containing polypeptidic antibiotics, which has been developed as a novel non-absorption feed additive. Based on the results of laboratory studies, the fermentation conditions of Streptomyces actuosus for the industrial production of nosiheptide and the factors affecting the quality of product were studied in this paper.First, we studied on cultivation conditions in a 10L fermentor. The results showed that the best inoculation volume was 1% and the best seed age was 28h. The optimized fermentation conditions in a 50L fermentor were feeding water in early days and feeding carbon source in later period. The fermentation titer of nosiheptide was 2,049ug/mL with a inoculation volume of 10%. Then the fermentation was scaled up in a 100L fermentor and in a 15 ton fermentor respectively with the same fermentation conditions. The fermentation titer of nosiheptide reached at 2,194μg/mL and 2,066μg/mL respectively, that is basically suitable for industrial fermentation production.Second, the stability of the strain producing nosiheptide was studied and the related standard was founded to assure the manufacture could be easily processed. The times of cell passage must be smaller than three; the time of the strain stored in 4℃refrigerator should not be longer than a month; the seed for manufacture should be used within three days in the same condition.In addition, we established the process for preparing nosiheptide by washing the mycelium with water and extracting nosiheptide from the mycelium by ethanol, decoloring by 717 resin, concentrating the ethanol extract to solid, washing the solid with water then washing it with hexane, and drying it at room temperature in vacuum to get refined product. We also studied on the stability of nosiheptide, and results showed that nosiheptide should be preserved as dry powder and the solution of nosiheptie should be preserved at condition of low temperature and darkness.Finally, we established the bioassay method of cup-plate method.