The invention relates to a method for separating and purifying
bacitracin by using a thermo-responsive
copolymer NPE-108, which comprises the following steps: a forward extraction step: uniformly mixing NPE-108 and
bacitracin fermentation liquor according to a volume ratio of 1: 4, adding
divalent manganese salt, adjusting the pH value to 8.5, uniformly oscillating, standing in a constant-temperature water bath kettle at 30 DEG C until two phases with a clear interface is formed, and taking out the upper phase; and a reverse extraction step: adding water of which the volume is half of that of NPE-108 into the upper phase obtained in the forward extraction step, uniformly mixing, adjusting the pH value to 5.5, standing in a water bath kettle at 60 DEG C until two phases with a clear interface are formed, and enriching
bacitracin in the upper phase. The thermo-responsive
copolymer NPE-108 is mixed with water to form a recoverable thermo-responsive two-aqueous-phase
system, and the method has the advantages of mild operation conditions, environmental friendliness and recoverable phase forming components, and is beneficial to large-scale bacitracin separation and application.