Abstract
Strains degrading and decolorizing reactive dyes, Procion blue HEGN and Procion red HE7B were isolated from water system, are named as RBK1 and RRK, the growth characteristics of which were investigated. Decolorization efficiencies after 42 hrs in batch culture were 95% and 77%, respectively. and the optimal culture condition of temperature and pH were $30^{\circ}C$, 7.0. Decolorization efficiencies in condition of aerobic shaking culture by strains RBK1 and RRK conspicuously increased, and culture by strain RBK1 was found as 95% after 42 hrs, while standing culture was 64%, Optimum nitrogen source was peptone, and It was found that decolorization efficiencies by strains RBK1 and RRK increased up to 4,000mg/l of peptone concentration as nitrogen source, but peptone concentration did' nt influence the decolorization efficiency in above 4,000mg/l. When the concentration of dyes were more than 800 mg/l and 400 mg/l respectively, the strains RBK1 and RRK, which degrade Procion bule HEGN and Procion red HE7B, showed a sharply decreased decolorization efficiencies; then the specific growth rate were $0.25hr^{-1}$ and $0.09hr^{-1}$.