Abstract
Chlorothalonil is a wide-spectrum fungicide that is widely used in the world. Chlorothalonil is known as a potential toxic pollutant due to its high application rate, persistence, and toxicity to humans and other species. With the Increase of necessity of bioremediation, this study was conducted to isolate the chlorothalonil dissipation bacteria from soil. Soil samples were collected from 184 sites of farmland and wastewater disposal soil.661 strains resistant to chlorothalonil were isolated by dilution method from chlorothalonil-containing enrichment culture. After incubating at $30^{\circ}C$ in 1/10 LB media containing 10 ppm of chlorothalonil for a week, dissipation ability of chlorothalonil was investigated by HPLC. Finally, a strain SH35B, capable of dissipating chlorothalonil efficiently, was selected. The strain SH35B was identified as Ochrobactrum sp. Ten ppm of chlorothalonil In 1/10 LB media were completely dissipated by the growth of Ochrobactrum sp. SH35B for 30 h at $30^{\circ}C$. In the isolated strain, the content of glutathione and the activity of glutathione S-transferase were supposed to be ones of the Important factors for chlorothalonil dissipation and were higher than those of control strains, Escherichia coli and Bacillus subtilis.
토양 시료를 대상으로 chlorothalonil을 함유한 최소배지에서의 집식배양과 배양 추 HPLC에 의한 잔류분석을 통해 chlorothalonil의 제거 능력이 우수한 균주 Ochrobactrum sp. SH35B를 분리하였다. 분리균 SH35B는 1/10 LB 배지에 함유된 10 ppm의 chlorothalonil을 30시간만에 완전히 제거하였으며, 20 ppm의 chlorothalonil의 경우 30시간 동안 88%를 제거하였다. 분리균의 Glu-SH함량과 glutathione S-transferase활성은 각각 1.33및 62.1 nmol/mg이었으며, 대조균인 E. coli나 B. subtilis 보다 높은 것으로 나타났다. 이상의 결과로부터 chlorothalonil의 전환에 있어서 세포내의 Glu-SH 함량과 glutathione S-transferase 활성 이 중요한 인자로 작용하는 것으로 생각된다.
