The invention discloses a method for extracting
tetanus toxin through
salting-out separation and application. The method comprises the following steps: carrying out first-stage
salting-out on a
clostridium tetani
fermentation liquor by using
ammonium sulfate, carrying out first-stage membrane
filtration, collecting a supernatant A, carrying out second-stage
salting-out on the supernatant A by using
ammonium sulfate, carrying out second-stage membrane
filtration, and collecting a precipitate B; wherein a membrane for the first-stage membrane
filtration comprises a
composite filter membrane with the pore size of 3.0-5.0 mu m and a
composite filter membrane with the pore size of 0.3-0.5 mu m, a membrane for the second-stage membrane filtration comprises a filter membrane with the pore size of 0.6-1.0 mu m, and the precipitate B comprises
tetanus toxin. The method can be used for treating a large-volume solution, remarkably shortening the
process time, reducing the labor cost, realizing full-flow channelization operation, effectively preventing
microbial pollution, facilitating
linear amplification of the process, remarkably improving the early-stage purification effect of
protein, removing a large amount of impurities and relieving the burden of subsequent purification steps.