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