<;P>;PROBLEM TO BE SOLVED: To provide an antibacterially active substance produced by bacteria belonging to the genus Rhodococcus having the antibacterial activity, and a method for controlling microorganisms by using the same. <;P>;SOLUTION: The antibacterially active substances are obtained by extracting the antibacterially active substances (fractions) from the cultured materials of the bacteria belonging to the genus Rhodococcus showing the antibacterial activities to the microorganisms, and the method for controlling sensitive microorganisms is provided by using these substances solely or as combined. <;P>;COPYRIGHT: (C)2009,JPO&INPIT