중금속으로 오염된 폐 광산에서 중금속(카드뮴, 구리)에 내성을 가지는 총 9개의 균주를 순수 분리한 후, 스크린 테스트를 거쳐 고효율의 중금속 제거 균주 JH1을 선별하였다. JH1 균주는 형태학적, 생리 생화학적 특징, 지방산 분석 그리고 16S rDNA 분석결과 Ralstonia eutropha JH1으로 동정되었다. 카드뮴으로 오염된 토양을 구연산(10 mM, pH 6.0)으로 세척 한 후, 그 세척수(카드뮴 110 mg/L)에서 균 농도(0.5, 1.0, 2.0, 4.0 g/L)에 따른 카드뮴 제거율을 확인한 결과, 5일 동안 각각 49.9, 84.4, 89.7, 89.9% 제거되었다. 또한 카드뮴(110 mg/L)과 구리(100 mg/L)를 함유하고 있는 구연산-세척수에서 Ralstonia eutropha JH1을 1.0 g/L로 접종했을 때, 6일 동안 카드뮴과 구리가 100% 제거 되었다. 저농도(10, 30, 60 mg/L)의 카드뮴과 구리를 각각 함유한 세척수 내에 Ralstonia eutropha JH1을 1.0 g/L로 접종하고 시간에 따른 제거율을 확인한 결과, 카드뮴과 구리 모두 10, 30, 60 mg/L에서 각각 12, 18, 48시간에서 100%제거되었다.
In this study, nine strains were isolated from heavy metal-contaminated soil in a mine. The high efficiency bacteria, JH1, to be able removal cadmium and copper, was selected by the screen test. JH1 was identified as Ralstonia eutropha by 16S rDNA analysis, fatty acid analysis, and its morphological and biochemical characteristics. After the cadmium-contaminated soil was washed with citric acid solution(pH 6, 10 mM), Ralstonia eutropha JH1 was inoculated in the soil washing water. In order to determine the optimal cell concentration for inoculation, cell concentrations were considered in 0.5, 1.0, 2.0, 4.0 g/L, respectively. The removal efficiencies for cadmium in each cell concentration of Ralstonia eutropha JH1 were 49.9, 84.4, 89.7% and 89.9% of 110 mg/L(Cd), after 5 days culture in soil washing water. When Ralstonia eutropha JH1 was inoculated in soil washing water containing each cadmium(110 mg/L) and copper(100 mg/L), each of them was removed completely during 6 days culture. The completely removing time for cadmium and copper in each low concentration, 10, 30 and 60 mg/L were 12, 18 and 48 hrs, respectively.
