Application of A Rational Feeding Strategy to Increase the Cell Density of Avian Pasteurella multocida.

Avian Pasteurella multocida infection, can cause serious economic losses to the poultry industry every year. The inactivated vaccines of avian Pasteurella multocida are used to prevent infection. Increasing the cell density of avian Pasteurella multocida is the key to the application of these inactivated vaccines. This can be achieved by controlling the feeding strategy. This study aimed to achieve high-cell-density cultivation of avian Pasteurella multocida by applying an appropriate medium and a rational feeding strategy based on viable cell growth and dissolved oxygen level variation during a fermentation process. An optimized medium suited for the growth of avian P. multocida was used. Meanwhile, besides the online real-time determination of viable cell density, the concentration of glucose was maintained at 1.5 g/L using a glucose-stat feeding strategy after 2 h. The selected nutrient mixture, including yeast extract, tryptone, betaine, VB1, and VH, was fed using a dissolved oxygen feedback feeding strategy after 4 h. As a result, the viable cell density and cell count of avian P. multocida under optimized conditions were increased to OD600: 9.38 and 4.58×1010 CFU/mL, which were higher by 7.27 and 7.26 times than those under the original conditions, respectively. [ABSTRACT FROM AUTHOR]