순수 분리 미생물을 이용한 오염 토양에서의 BTEX 생분해 특성과 미생물 군집 변화

BTEX Biodegradation in Contaminated Soil Samples Using Pure Isolates and Changes in the Mixed Microbial Community Structure

  • 정경미 (한국과학기술연구원 수질환경 및 복원연구센터) ;
  • 최용수 (한국과학기술연구원 수질환경 및 복원연구센터) ;
  • 홍석원 (한국과학기술연구원 수질환경 및 복원연구센터) ;
  • 이수진 (한국과학기술연구원 수질환경 및 복원연구센터) ;
  • 이상협 (한국과학기술연구원 수질환경 및 복원연구센터)
  • Chung, Kyung-Mi (Water Environment and Remediation Center, Korea Institute of Science and Technology) ;
  • Choi, Yong-Su (Water Environment and Remediation Center, Korea Institute of Science and Technology) ;
  • Hong, Seok-Won (Water Environment and Remediation Center, Korea Institute of Science and Technology) ;
  • Lee, Soo-Jin (Water Environment and Remediation Center, Korea Institute of Science and Technology) ;
  • Lee, Sang-Hyup (Water Environment and Remediation Center, Korea Institute of Science and Technology)
  • 발행 : 2006.07.31

초록

본 연구에서는 BTEX로 오염된 저질로부터 순수 분리한 BTEX를 탄소원으로 $NO_3$-N를 전자수용체로 이용하는 미생물의 오염토양에 대한 현장 적용 가능성을 평가하였다. 이와 함께 주입한 순수 분리 미생물과 토착 미생물과의 상호 관계를 관찰하기 위하여 시간 경과에 따른 오염된 토양에서의 미생물 군집 변화도 관찰하였다. 이를 위해 BTEX로 오염 가능성이 적은 지역으로부터 채취한 토양 시료 100 g에 benzene, toluene, ethylbenzene, o-xylene을 각각 일정량 주입한 후, 동정 분리한 Pseudomonas stutzeri strain 15(DQ 202712):Klebsiella sp. strain 20(DQ 202715):Citrobacter sp. strain A(DQ 202713)를 2;1:1의 비율로 주입하여 BTEX 분해 효율과 미생물 군집 변화를 관찰하였다. 실험결과, $NO_3$-N와 BTEX가 모두 존재하는 조건에서 동정 분리한 미생물에 의한 분해 효율이 가장 높게 관찰되었다. 그리고 PCR-DGGE를 통한 미생물 군집 변화 관찰 결과, 토양 내 존재하는 다양한 미생물들의 peak는 대부분 감소된 반면, 주입한 동정분리 미생물 peak는 증가되는 것을 관찰할 수 있었다. 그러나 주입한 미생물 3종 가운데 Pseudomona stutzeri만이 우점화 된 결과가 관찰되었다.

In our previous studies, we have isolated bacteria from BTEX-contaminated sediment, which utilized BTEX as a sole carbon source and $NO_3$-N as an electron acceptor. For the possibility of field application, we have applied co-culture of those isolates in the BTEX-contaminated soil and evaluated their biodegradation efficiencies. To investigate the relationship between the isolates and indigenous microorganism in soil, changes of microbial community structure in soil samples with respect to time were monitored. To examine this, soil samples were artificially contaminated with benzene, toluene, ethylbenzene and o-xylene. BTEX-degrading bacteria such as Pseudomonas stutzeri strain 15(DQ 202712), Klebsiells sp. strain 20(DQ 202715) and Citrobacter sp. strain A(DQ 202713) were injected into the soil samples in the ratio of 2:1:1. Our results showed that the highest BTEX biodegradation efficiency was achieved when both BTEX and $NO_3-N$ existed simultaneously. The change in soil microbial community structure was characterized by PCR-DGGE analysis comparing the relative DGGE band intensities. The band intensities of indigenous microorganisms in the soil were reduced by injecting co-culture of the three isolates. On the contrary, the relative band intensities of the isolates were increased. Among the three isolates, Pseudomonas stutzeri strain 15 rendered the highest band intensity. This indicates that the Pseudomonas stutzeri was the dominant microbial species found in the soil samples.

키워드

참고문헌

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