The invention discloses a preparation method and application of a recombinant A-type
botulinum toxin, and aims to industrially produce the recombinant A-type
botulinum toxin by utilizing the preparation method of the recombinant A-type
botulinum toxin provided by the invention. The method comprises the following steps: firstly, constructing
genetically engineered bacteria capable of heterologously expressing a
botulinum toxin A gene in host
bacteria by virtue of a
genetic engineering means, then accumulating recombinant
botulinum toxin A in a strain by virtue of the
genetically engineered bacteria through high-density
fermentation, collecting fermented thalli, crushing and purifying to obtain the recombinant
botulinum toxin A, and finally, preparing the recombinant botulinum
toxin A by virtue of the recombinant botulinum
toxin A. And adding an auxiliary poising agent and a protective agent to prepare a liquid agent or a freeze-
drying agent to obtain the recombinant A-type botulinum
toxin for injection. According to the technical scheme, the complete recombinant botulinum toxin A with the purity as high as 99.9% is obtained, the yield is as high as 7000000 U / L, and the complete recombinant botulinum toxin A has no obvious difference from natural botulinum toxin A in
structure and function and can be applied to multiple fields such as
medical treatment, medical beauty and military affairs.