System and method for cleaning contaminated matter comprising dioxins and preparation for decomposing dioxins

A method of cleaning contaminated matter comprising dioxins by decomposing the dioxins in the contaminated matter, wherein the method comprises:

• culturing Bacillus midousuji by a process comprising:
• mixing a dioxin-containing substance comprising fly ash with a medium comprising a nutrient source of Bacillus midousuji, supplying oxygen to the medium, and controlling the temperature of the medium to 62° C. or above, which allows activity of the Bacillus midousuji;
• crushing cells of Bacillus midousuji that were cultured in the culturing step, to obtain crushed cells of Bacillus midousuji;
• subjecting the crushed cells of Bacillus midousuji to centrifugation to separate the crushed cells into a pellicle fraction comprising crushed cells containing a pellicle, and a cytoplasm fraction comprising crushed cells containing cytoplasm;
• and
• mixing the pellicle fraction, the contaminated matter, and an aqueous medium, wherein the pellicle of Bacillus midousuji breaks the ether bond of the structure of the dioxins.