• Biotechnology and Bioprocess Engineering:BBE
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• v.8 no.2
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• pp.101-105
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• 2003

Recombinant bioluminescent bacteria were used to monitor and classify the to xicity of azo dyes. Two constitutive bioluminescent bacteria, Photobacterium phosphoreum and Es-Cherichia coli, E, coli GC2 (lac::luxCOABE), were used to detect the cellular toxicity of the azo dyes. In addition, four stress-inducible bioluminestent E. coli, DPD2794 (recA::luxCDABE), a DNA damage Sensitive strain; DPD2540 (fabA::luxCDABE), a membrane damage sensitive strain; DPD2511 (katG::luxCDABE), an oxidative damage sensitive strain; and TV1061 (grpE::luxCDABE), a protein damage sensitive strain, were used to provide information about the type of toxicity caused by crystal violet, the most toxic dye of the 16 azo dyes tested. These results suggest that azo dyes result in serious cellular toxicity in bacteria, and that toxicity monitoring and classific ation of some azo dyes, In the field, may be possible using these recombinant bioluminescent bacteria.

• Biotechnology and Bioprocess Engineering:BBE
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• v.5 no.6
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• pp.395-399
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• 2000

Five different freeze-dried recombinant bioluminescent bacteria were used for the detection of cellular stresses caused by endocrine disrupting chemicals. These strains were DPD2794 (recA::luxCDABE), which is sensitive to DNA damage, DPD2540 (fabA::luxCDABE), sensitive to cellular membrane damage, DPD2511 (katG::luxCDABE), sensitive to oxidative damage, and TV1061 (grpE::luxCDABE), sensitive to protein damage. GC2, which emits bioluminescence constitutively, was also used in this study. The toxicity of several chemicals was measured using GC2. Damage caused by known endocrine disrupting chemicals, such as nonyl phenol, bisphenol A, and styrene, was detected and classified according to toxicity mode, while others, such as phathalate and DDT, were not detected with the bacteria. These results suggest that endocrine disrupting chemicals are toxic in bacteria, and do not act via an estrogenic effect, and that toxicity monitoring and classification of some endocrine disrupting chemicals may be possible in the field using these freeze-dried recombinant bioluminescent bacteria.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.212-215
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• 2000

Recombinant bioluminescent bacterial strains that use specific promoters fused to the bioluminescence genes (lux genes) have been applied in environmental monitoring. Advantages of using recombinant bioluminescent bacteria as blosensing cells include rapid responses, low costs, and improved reproducibility. In this study, a recombinant Escherichia coli, GC2, containing a lac::luxCDABE fusion immobilized with solid agar media and glass beads was used to estimate the effect of this soil flushing technique. This bacterium constitutively emits light under normal conditions (no toxic chemicals). When growth and metabolism of these bioluminescent bacteria is inhibited by their exposure to toxic chemicals, the bioluminescence (BL) is reduced. A biosurfactant, rhamnolipids, was used to extract phenanthrene from the soil after flushing.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2003.06a
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• pp.129-131
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• 2003

Recombinant bioluminescent bacteria and cultured human cells were applied for toxicogenomic analysis of environmentally hazardous chemicals. Recombinant bioluminescent biosensing cells were used to detect and classify the toxicity caused by various chemicals. Classification of toxicity was realized based upon the chemicals' mode of action using DNA-, oxidative-, protein, and membrane-damage sensitive strains. As well, a simple double-layered cell culture system using Caco-2 cells and Hep G2 cells, which mimic the metabolic processes occurring in humans, such as adsorption through the small intestine and biotransformationin both the small intestine and the liver, was developed to investigate the toxicity of hazardous materials to humans. For a more in-depth analysis, a DNA microarray was used to study the transcriptional responses of Caco-2 and Hep G2 cells to benzo〔a〕pyrene.

• Biotechnology and Bioprocess Engineering:BBE
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• v.5 no.3
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• pp.202-206
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• 2000

The genetically-engineered Escherichia coli strain, DPD2540, which contains a fabA:::luxCDAbefusion gene, gives a bioluminescent output when membrane fatty acid synthesis is needed. For more pactical application of this strain in the filed as biosensor, freezedrying was adopted. A 12% surcrose solution with Luria-Bertani (LB) broth, as determined by the viability after freeze-drying, was found to be most most effective composition for lyophilization solution among various compositions testitons tested. Rapid freezing with liquid nitrogen also gave the best viability after freeze-drying as compared to samples frozen at-7$0^{\circ}C$ and -2$0^{\circ}C$. The biosensing activities of the cells showed a greater sensitivity when the cells from the expontial phase were freeze-dried. Finally, the optimum temperature for use of the freeze-dried cells in the biodencor field was determined.

• Biotechnology and Bioprocess Engineering:BBE
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• v.4 no.1
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• pp.59-62
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• 1999

The recombinant bacteria strain DPD2540, containing a fabA::luxCDABE fusion, was used to detect the toxicity of various chemicals in this study. Membrane damaging agents such as phenol, ethanol, and cerulenin induced a rapid bioluminescent response from this strain. Other toxic agents, such as DNA-damaging or oxidative-damaging chemicals, showed a delayed bioluminescent response in which the maximum peak appeared over 150 min after induction. This strain was also tested for measurement of toxicity in field samples such as wastewater and river water effluents.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.715-718
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• 2000

The character of a recombinant bioluminescent bacteria's light emission enables us to monitor toxicity in water, soil and air. In this study, various bioluminescent responses to water samples containing toxic chemicals, such as phenol and mitomycin C, were obtained and analysed through the use of a multi-channel two-stage minibioreactor system. The bioluminescent pattern from each channel can be used as a standard for identifying the degree of toxicity in field samples. When various concentrations of toxic chemicals were injected in a step manner, different bioluminescent patterns were obtained. Also this system showed variation in its bioluminescent pattern as the injection manner was changed, i.e. using a modified version of the bell-curve type injection. In conclusion, the toxicity was shown to be related with the bioluminescent response when using these standard bioluminescent patterns. Comparing this standard with a bioluminescent response from a field sample, we can estimate the degree of which the sample is toxic.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2000.04a
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• pp.94-99
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• 2000

Bioluminescence is being used as a prevailing reporter of gene expression in microorganisms and mammalian cells. Bacterial bioluminescence draws special attention from environmental biotechnologists since it has many advantageous characteristics, such as no requirement of extra substractes, highly sensitive, and on-line measurability. Using bacterial bioluminescence as a reporter of toxicity has replaced the classical toxicity monitoring technology of using fish or daphnia with a cutting-edge technology. Fusion of bacterial stress promoters, which control the transcription of stress genes corresponding to heat-shock, DNA-, or oxidative-damaging stress, to the bacterial lux operon has resulted in the development of novel toxicity biosensors with a short measurement time, enhanced sensitivity, and ease and convenient usage. Therefore, these recombinant bioluminescent bacteria are expected to induce bacterial bioluminescence when the cells are exposed to stressful conditions, including toxic chemicals. We have used these recombinant bioluminescent bacteria in order to develop toxicity biosensors in a continuous, portable, or in-situ measurement from for air, water, and soil environments. All the data obtained from these toxicity biosensors for these environments were found to be repeatable and reproducible, and the minimum detection level of toxicity was found to be ppb (part per billion) levels for specific chemicals.

• Environmental Analysis Health and Toxicology
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• v.19 no.3
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• pp.295-305
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• 2004

본 연구에서는 유전자 재조합 발광 박테리아를 이용하여 농약에 대한 박테리아의 스트레스 반응과 세포 독성을 분석하였다. 15종류의 농약에 대하여 유전자 손상, 생물막 손상, 산화적 손상 및 단백질 손상을 측정할 수 있는 발광 박테리아와 독성 유무로 인한 세포 독성을 측정할 수 있는 발광 박테리아, 5종을 이용하여 스트레스 반응을 분류하고 세포 독성 정토를 분석하였다. 그 결과, 농약의 화학적 구조가 박테리아의 스트레스 반응에 영향을 미치며, 산화과정이 진행 됨에 따라 독성의 작용 기작이 변하는 것을 확인 할 수 있었다. 이와 같은, 유전자 재조합 발광 박테리아를 이용한 생물체내의 독성 메커니즘에 대한 분석은 생태계 유해물질들에 의한 독성을 분석하고 예상하기 위해 적용될 수 있을 것이다.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.391-391
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• 2003