Isolation and Characterization of 3,4-Dichloroaniline Degrading Bacteria from a Sandbank

갯벌에서 분리한 3,4-Dichloroaniline 분해 미생물의 특성

The compound 3,4-dichloroaniline (DCA) is an aromatic amine used as an intermediate product in the synthesis of herbicides, azo-dyes and harmaceuticals. It is also a degradation product of some herbicides (diuron, propanil, and linuron) and of trichlorocarbanilide, a chemical used as active agent in the cosmetic industry. 3,4-DCA, however, is considered potential pollutants due to their toxic and recalcitrant properties to humans and other species. A bacterium capable of growth on 3,4-DCA was isolated by dilution method from 3,4-DCA-containing enrichment culture. Finally, a strain, YM-14, capable of degrading efficiently 3,4-DCA was isolated from a sandbank. The isolated strain, YM-14 was identified to be Arthrobacter sp.. Fifty ppm 3,4-DCA in 1/10 LB media was completely degraded by the growth of Arthrobacter sp. YM-14 for 12 h at $30^{\circ}C$. The isolated strain is capable of growth on 3,4-DCA as sole carbon source and also able to degrade other chloroaniline compounds. Also, the isolated strain showed high level of catechol 1,2-dioxygenase activity by 3,4-DCA exposure. The catechol 1,2-dioxygenase was supposed to be ones of the important factors for 3,4-DCA degradation.

3.4-dichloroaniline (DCA)를 함유한 최소배지에서의 집식배양과 배양 후 HPLC에 의한 잔류분석을 통해 3,4-DCA의 분해 능력이 우수한 균주 Arthrobacter sp. YM-14를 여천석유화학공단 인근의 갯벌에서 분리하였다. 분리균 YM-14는 1/10 LB 배지에 함유된 50 ppm의 3,4-DCA를 12 시간 만에 완전히 제거하였다. 이외에도 분리균 YM-14는 3-chloroaniline(CA), 2,5-DCA 및 3,5-DCA의 분해 활성을 나타내었으나 2-CA, 4-CA와 2,4-DCA에 대한 분해활성을 가지고 있지는 않았다. 또한, 분리균 YM-14에서 3,4-DCA의 유도에 의한 catechol 1,2-dioxygenase 활성의 증가가 관찰되었다. 이러한 결과는 catechol 1,2-dioxygenase이 3,4-DCA 분해에 관여하는 중요한 효소군중의 하나로 생각된다.