Bioreactors for efficient degradation of the Fe (III) EDTA chelate using bacteria have been developed. In this study, we have investigated on the immobilized bacteria Bacillus sp. B-3. As a immobilization method, a physical adsorption or entrapping method which can easily immobilize the bacteria inexpensively has been tried. A spherical cellulose (SC), cylindrical polypropylene (CPP), and polymeric spherical hydrogel (SHG), which are commercially available products, were used as supports for the bacteria, and a photo-cross linkable prepolymer resin ENTG was used to entrap the bacteria. A degradation test for the Fe (III) EDTA conducted with an initial concentration of 100mg/l in a medium containing polypeptone and yeast extracts as nutrients. As a result, the bacteria adsorbed and immobilized on SC, CPP and SHG, and entrapped into ENTG degraded 79%, 73% and 71%, and 84% of EDTA, respectively, in 7 days, while none of the bacteria were degraded for a medium without the nutrients. After the 7-day degradation test, the same test was repeated four times with the same immobilized bacteria on SC. As a result, a decrease in the degradation ability of the immobilized bacteria could not be observed (within±5.6% deviation through repeated runs) . In addition, a decrease in the EDTA degradation ability was not found for the immobilized bacteria stored at room temperature for at least 90 days.

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