[LC-ESI/MS identification and reduction of impurities in spiramycin fermentation]

There are several impurities in the spiramycin fermentation broth which leads to a lower yield and lower quality of the product. Four impurities in spiramycin broth have been simultaneously separated and identified by LC-ESI/MS. The generation of these impurities was attributed to the fluctuation of glucosylation in spiramycin biosynthesis. Nitrogen sources, ammonium in particular, were found to play an important role at the glucosylation. Aided with the information of LC-ESI/MS analysis and subsequent optimization of the culture medium, better culture medium of shake flask was designed, which leads to reduction of impurities by 22% - 88%.