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To obtain higher yield of 2,3-dihydroxybiphenyl(2,3-DHBP) dioxygenase by recombinant E. coli CK1092 carrying pcbC gene of Pseudomonas sp. P20, the environmental and physiological factors were investigated and the cultural conditions using jar fermentor were studied. E. coli CK1092 was grown in LB medium supplemented with 2% sucrose, as a basal medium. The effect of various metal ions on the enzyme production was investigated. In particular, the enzyme production increased in the presence of Fe´ and Fee*, and showed the maxium at the concentration of 10-5 M. The enzyme production was increased by 55% in the medium containing Fe ´´ (10´5 M) ion. The optimal temperature and initial pH for cell growth were 3790 and 7.0, respectively. In the culture using a fermentor at 37°C, the optimal conditions for the enzyme production were obtained at the initial pH 7.0, 1 v/v/m of aeration rate, 200 rpm of agitation speed. It was found that enzyme activity was higher when cultivated without pH control than with pH control.
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