According to the optimization experimental results of feather fermentation using the compound mutation strain of
Bacillus subtilis which was obtained through fermentation condition of ultraviolet ray and sodium nitrite, This paper
presented the optimum fermentation condition was culture temperature 33ć , culture duration 72 hours, shaker speed
170rpm, inoculums 6%, liquid volume 100mL/500mL, initial pH value of the fermentation medium which was
suitable for the growth of the strain 7.0, and the optimal pH value for producing enzyme by the strain was 7.5-8.0.
During the 60 hours culture, the highest yielding rate for producing enzyme by the strain was 1.267 U/mL. The
decompose rate of the feather after 72 hours was 69.61%. The amino acid concentration in the fermentation medium
fluid reached 22.66mg/mL. This research provided the optimum process parameters for producing biological
fermentation feather powder in industry.