The reaction was started by adding 0.25 mL of a FDA solution (2 mg mL1) and incubated in a shaker incubator (New Brunswick, Excella E24) at room temperature and 200 rpm. A490 was measured using a UV/Vis spectrophotometer (Thermo Scientific, Spectronic Genesys2)afterthe removalof thesoilbycentrifugation and filtration. The samples were analyzed in triplicate