Verification method: Inoculate the strain into nutrient broth medium and culture on a shaker at 37 ℃ for 18-24 hours. The bacterial solution is significantly turbid. Then dip the inoculation ring into the bacterial solution and streak culture on the medium containing L-histidine and the medium without L-histidine, respectively. After 24 hours of cultivation at 37 ℃, observe. The strain grows well on the surface of the L-histidine containing medium Agar plate (left image), but is inhibited in the absence of L-histidine medium Agar plate, and does not grow or grows a few colonies (right image)