<p>It is intended to provide a method of producing a colistin bulk powder without resorting to a decolorizing step whereby problems occurring in the existing production methods (for example, a prolonged production time due to the decolorizing step, an increase in the cost due to a lowering in the yield of the main colistin component and an environmental burden caused by the evolution of a carbon waste) can be overcome. Namely, Bacillus polymyxa var. colistinus which is capable of producing a colistin bulk powder having a high whiteness; a colistin bulk powder having a high whiteness; and a method of producing a colistin bulk powder having a high whiteness.</p>
