Faculty of Engineering and Natural Sciences
Application of microbial cell biosensors for toxicity analysis
Jin Hyung Lee
*Future Convergence Ceramic
Korea Inst. of Ceramic Eng.&Tech.
Recently, various recombinant bioluminescent bacteria were constructed by fusing different stress promoters to the bacterial lux genes for their utilization as microbial cell biosensors. These cell biosensors are very specific in their bioluminescent responses based on the promoter fused upstream of the lux operons within each strain.
In this talk, I will present the application of recombinant bioluminescent bacteria to toxicity monitoring and analysis. Firstly, the continuous monitoring of water-borne toxicity using several microbial biosensors in continuous stirred tank reactors (CSTRs) will be presented. In these studies, we found that these systems performed stably and continuously due to the physical separation of the culture reactor from the test reactor. In addition, we carried out the toxicity classification and chemical-specific continuous monitoring in these systems.
In order to analyze the inherent toxicities of different samples in a high throughput manner, we constructed cell array biochips by immobilizing the microbial biosensors within a hydrogel matrix. The capacity of the cell array chip to be used in toxicity classification was proven in tests with three representative toxicants, mitomycin C (which causes DNA damage), paraquat (oxidative damage) and salicylic acid (membrane/protein damage). Using the optimized format found, an oxidative stress-specific cell array biochip was fabricated using twelve recombinant strains that are responsive to oxidative radicals. The results showed that these cell array chips can be implemented as tools for characterizing the toxicities of various compounds.
At the last part of this talk, I will present how to use a panel of microbial biosensors to analyze the toxicities. For example, we analyzed the toxic mode of action for silver nanoparticles using a panel of stress-specific bioluminescent bacteria and then confirmed the results through real-time PCR experiments.
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August 21, 2009, 14:00, FENS G032