Abstract: The cultivation of GN52 strain of Riemerella anatipestifer (RA) in improved yeast medium using liquid fermentation devices was researched. Explore Riemerella anatipestifer's growth rhythm, culture method, the optimum time for acquisition as well as the best condition for inactivation via coloration and microscopic examination, viable count, measurement of D_{450 nm} and pH value, etc. The results indicated that during the cultivation of RA the pH value stayed stable; the number of viable bacteria peaked at 320 million-350 million CFU/mL after fermenting for 20 hours at 37 ℃; inactivate Ag for 18 hours at 37 ℃ by 0.3% methanal was optimum; there was kind of functional relation between D_{450 nm} and the number of viable bacteria, the latter could be reckoned through measuring D_{450 nm} of RA liquid culture medium.

Key words: Riemerella anatipestifer; fermentation culture