Resarch On PH And Dissolved Oxygen Control Strategy And Key Proteins During Process Of 1,3-Propanediol Fermentation

This paper research on pH, dissolved oxygen control strategy and four key proteins during process of 1,3-propanediol fermentation.The affects of different pH on the cell growth and products synthesis during process of 1,3-propanediol fermentation were studied. It was found that high pH made for higher cell growth speed, the increase of Lactate synthesis, and lower molar ratio of 1,3-propanediol; otherwise low pH made for lower cell growth, the increase of 2,3-butanediol synthesis, and the better cell activity during the process of fermentation. Therefore, need to control a suitable pH in the fermentation process, and the lactate is mainly produced in the latter part of the fermentation process according to the synthesis law. We choose higher pH during the first two phases of the fermentation process, and lower pH during the last two phases. The synthesis of lactate was inhibited, and increased of 1,3-propanediol molar ratio and concentration. After the optimization of pH control strategy, got 1,3-propanediol concentration:65g/labove, the molar ratio of 0.6mol/mol.Different dissolved oxygen levels during the fermentation process can affect the cell growth and cell activity. The cell growth rate was low and cell activity maintenance time is long at a lower dissolved oxygen level. Therefore, by increasing the dissolved oxygen level can speed up cell growth rate, reduce glycerol consumption, shorten the fermentation period, increase the productivity. By research on the control strategy of dissolved oxygen level in the fermentation process, fermentation process was shortened to 24 hours, got 1,3-propanediol concentration:62g/labove, the productivity 2.5g/(L*h).For the proteomics research of the cell during the fermentation process, the One-dimensional verify the repeatability of sample treatment, and got a preliminary understanding about the relationship between the four key proteins and the fermentation process. Research on GDH, GDHt, PDOR and DHAK.