The invention discloses bacillus polymyxa DYr4.4 with
broad spectrum antibacterial activity and a preparation method and application. The number is CCTCC M 2018023. The method comprises the steps thatA, a single
bacterial colony of a
bacterial strain is selected under the aseptic environment, inoculated to a culture solution and placed in a constant-temperature culture oscillator, the temperatureand rotation speed are adjusted, and oscillation culture is conducted; B, a
fermentation solution is placed in each
bottle, the bottles are placed in a large-amplitude constant-temperature freezing shaking table, and oscillation culture is conducted; C, the culture solution is prepared, wherein solutions are added to a tank in sequence, a tank body is sealed, the culture solution is heated and disinfected, an
inoculation port is disinfected by igniting
alcohol, 2 L of
fermentation solution prepared in the last step is poured into the tank under the condition that the
alcohol burns continuously, and the rotation speed of a stirrer is adjusted; D, the
fermentation solution is filtered, an auxiliary material namely light
calcium carbonate powder is added to the filtered fermentation solution, the
mixed solution is placed in a centrifugal
spray drying tower and dried, and
dry powder is collected. The bacillus polymyxa DYr4.4 is applied to preparation of
medicine for treating or preventingrust diseases of
pear trees.
Dry powder fermentation of the
bacterial strain has the remarkable anti-
disease effect on the
rust diseases of the
pear trees, the prevention effect reaches 67.09% or above, and leaf falling of the
pear trees in advance is remarkably inhibited.