| Strain improvement, scale-up of fermentation processes and kinetics of the three antibiotics (pristinamycin, teicoplanin, and rifamycin 13) were studied. he production medium of pristinamycin by S(reptomyces prisiinaespiralis ATCC 25486 was optimized. The suitable production medium was achieved by single factor experiments and orthogonal experiments. It contains: starch 3%, glucose 2%, soybean meal 2%, peptone 0.5%, fish meal 0.5%, (NH)2S040.15%, MgSO4 0.1%, KI-12P040.04%, CaCO3O.4%, soybean oil 1%, propyl alcohol 0.4%(added at the 18th hour of batch fermentation). The pH value of the medium is 6.0. Carbon catabolite repression and nitrogen catobolite repression was observed in pristinamycin fermentation. Based on the biosynthesis pathway and the metabolic regulation of pristinamycin. teicoplanin and rifamycin B, strain improvement of these antibiotics was performed by mutation and rational screening to improve their productivity and product quality. According to the metabolic pathway of pristinamycin, a rational selection procedure with U. V. mutation was performed to obtained high pristinamycin productivity. A strain S. pristinaespiralis 12-55 with 0.1%AAr, 0.3%AAt, 0.1%Valr, 0.1 %KTMr, and 0.1% DOGr was obtained, whose pristinamycin productivity reaches 3000tt/ml which was 100 times higher than that of the parent strain ATCC 25486. The analysis of kinetic experiments indicated that the pristinamycin fermentation with S. pris(inaespiralis 12-55 is non-growth associated. Actinoplanes teichoniyceticus 97-5-74 for teicoplanin production had undergone mutation and screening with various methods. In this work, a valine hydroxamate resistant mutant strain was screened for the enhancement of valine production, which is the important precursor for teicoplanin TA22 synthesis. A VHr mutant strain A. eichomycehicus 98-1-227, which is high in total potency and TA22 titer, was obtained from the parent strain 97-5-74. The results of the shaking flask fermentation experiments suggested that teicoplanin fermentation with A. teichomyceticus 98-1-227 is also non-growth associated. Rifamycin B has been commercially produced by a strain of Amyco/atoposis mediterranei. In this work, an industrial applied strain XC 102 was used for further screening. A special mutation and screening procedure was adopted in this work to select a strain which could growth well on the medium with high concentration of VII 0.1% trp, 0.5% trp, 0.1% PHBA, and 0.1% propyl acid to alleviate the inhibition caused by both aromatic amino acid and PHBA in the metabolic pathway of rifamycin B, as well as to enhance the production of propyl acid which is the precursor of rifamycin B. By above methods, a strain A. niediterranei XC 9-25 was obtained. The rifamycin 13 productivity reaches l0000uIml, which is 1.38 times higher than that of the parent strain XC 102. Except for high productivity, strain XC 9-25 possesses the advantage of producing less mycclia, that is favorable in rifamycin recovery. According to the different characteristics of pristinamycin, teicoplanin, and rifamycin B fermentation, the scale-up of the fermentation processes for three antibiotics were studied, and the principles of scale-up were proposed. Pristinamycin fermentation needs high dissolved oxygen and is not very sensitive to shearing strength. Scale-up of pristinamycin fermentation from shaking flas...
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