Srtain Screening For High Productivity Of Oxytetracycline

Oxytetracycline is an important secondary metabolite of streptomyces rimosus, and it is one of the broad-spectrum antibiotics with a wide application.in medical and feedstocks.Oxytetracycline is manufactured by fermentation with streptomyces rimosus. With the improvement of the manufacturing process, the capacity of traditional process can not be increasing no more. How to improve the capacity and reduce the cost has been became the concern of the whole industry. An important fact has been discovered in the process of innovation and research, that the streening of strain acts an important role in the process of improving capacity, one strain corresponding to one process, the process and strain are co-related. Therefore, the selection of high production strain of Oxytetracycline would be very important, finding a new screening method to get obviously strain variation would be an urgent work.Streptomyces rimosus that producing oxytetracycline has been mutagenized, its ability is limited. So it is very ergent to find a new screening method. We screened a new strain No.173from No.68by constantly streening, whose phenotype and metabolization rate are obviously different from its parent. We used y-ray to irradiate No.68, and get higher producing strains which are used for father strain in next UV-ray screening. The higher strains were constantly screened with several antibiotics.The order of the antibiotic used in this rearch is streptermycine, rifamycin sv, paromomycin, kanamycin and geneticin.In this paper, we improved the screening craft by adjusting the fermentation. The cycle of selecting shortens two days and it was eight days originally. The ratio of carbone/nitrogen was reduced, in order to adjust growing and fermentation, fermentation finishes in two days. It not only improves work efficiency, but also shortens the slants stored time.The properties of No.173were researched in this paper, also its purity, stabilization, and the etabolization rate. The purity of No.173is99.6%, and it displays good stabilization. The R is200U/mL in three generations. It uses sugar more moderately and uses nitrogen more rapidly, besides, it endures higher phosphorus than others. The properties give references to our producing, and its titer increased13.3%.