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Compounds, propionic acid and its derivatives as an important C3 platform uses a wide range, can be applied to organic synthesis, food, feed, spices, paints, dyes, pharmaceuticals. Propionic industrialized production methods for the chemical synthesis, with the prices of fossil fuels as well as the pursuit of the green, healthy biological source of chemicals, fermentation production of propionic acid by an increasing number of researchers concern. In this thesis, a can in the massive accumulation of extracellular propionic acid production Propionibacterium acnes (Propionibacterium acidipropionici) for the production of strains, the high production of propionic acid, high yield and high production intensity target, propionic acid fermentation process conducted a series of optimization. The main findings are as follows: (1) progressively passage way by gradually increasing the selection pressure (propionic acid concentration) to improve P.acidipropionici acid resistance. After nearly a year of adaptive evolution obtained can withstand 20 g / L propionic evolutionary strain (the starting strain tolerated propionic acid concentration of 2.5 g / L). 20g / L glycerol batch fermentation conditions, and compared to the original strain, shorten the fermentation time 14.3% of dry cell weight increased by 23.1%, propionic acid production increased by 41.1%, 65% increase in the intensity of production. On the evolution of the strain and the original strain intracellular microenvironment evolutionary strain energy charge levels increased by 100%, and oxidation-reduction level of 16.5% and 52.7% increase in the H-ATPase activity. (2) shake flask culture conditions were optimized, the best nutritional and environmental conditions of the propionic acid fermentation: yeast extract 10 g / L, peptone 5 gg / L glycerol 20g / L of CoCl2 10mg / L, inoculum size 10% , temperature 30 ° C. (3) the training mode of the propionic acid fermentation in a 7L fermenter study investigated under different glycerol concentration propionic batch fermentation process, found only difficult to achieve the high yield of cells and propionic acid, the high yield by the batch culture high production intensity unified. Pulse feeding, constant rate fed-batch culture method can achieve a high yield of propionic acid bacteria cells and propionic acid. Comprehensive comparison of view, the initial glycerol concentration of 30 g / L, 72h-120 h constant speed stream to increase the concentration of the glycerol solution of 400 g / L, the flow rate is controlled to 0.01 L / h when the most suitable for propionic acid fermentation, fermentation 220h , cell dry weight of 4.46 g / L, propionic acid production reached 44.62g / L. (4) The optimal training mode on a 10 m3 tank fermentation pilot, the highest propionic acid production reached 47.28g / L, 6% higher than 7L tank, fermentation cycle to 240h, compared 7L tank extend 20h, indicating that the flow addition mode has a better application, to achieve a high yield of propionic acid fermentation scale industrialized production. (5) The study found that the fermentation broth after incubation at 70 ℃ 10min can reduce the viscosity of the fermentation broth to improve the efficiency of the filter; effect of different thickness celite compound used as a filter aid the extraction of the object product calcium propionate Jia, on a Buchner funnel with a diameter of 10cm, before adding 1 g of the fine diatomite cake, another short time after mixing 1g crude celite is added to the fermentation broth through insulation, vacuum pump filtration, not only filters, and The filtering effect is good; will be the filtered fermentation liquid spray drying will be able to get product calcium propionate, specific spray drying conditions: inlet temperature of 180 ° C to 200 ° C, outlet temperature gt; 85 ℃.
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