Abstract: The bacteriophages damage to 2-keto-D-gluconic acid fermentation in the industrial process was investigated. After infection by the bacteriophages, the morphology of the bacteria, the changes of the seed culture and the fermentation course were also observed. The results showed that the bacteriophages infection resulted in the reduction of conversion ratio, the prolonga- tion of fermentation period and the decrease of fermentation broth filtration rate. The damage caused by the bacteriophages infection had significant differences among earlier-, middle- and later-fermentation stages(p<0.01) respectively. The earlier the infection started, the more serious the damage was.

Key words: bacteriophage, 2-keto-D-gluconic acid, fermentation