Monday, October 22, 2007 : 1:00 p.m.

Bioluminescent Yeast-Reporter Systems for Screening Chemicals

John Sanseverino, Ph.D., Melanie Eldridge, Alice Layton, Jason Yarbrough, T. Wayne Schultz and Gary Sayler, University of Tennessee

The Endocrine Disrupter Screening and Testing Advisory Committee (EDSTAC) created by the Environmental Protection Agency (EPA) was mandated with developing methods to screen approximately 87,000 chemicals for biological effects on estrogen, androgen, and thyroid hormone systems.  As part of this mandate, EDSTAC proposed that EPA develop rapid, high throughput screening systems to assess a compound’s effects on hormonal systems.  Recently, two yeast strains, S. cerevisiae BLYES and S. cerevisiae BLYAS, were developed that produce a rapid, measurable bioluminescent signal in response to either an estrogenic or androgenic compound, respectively. The BLYES assay produced a 17β-estradiol standard curve with an EC50 value of 7.3 ± 3.1 x 10-10 M (n = 20) and lower and upper limits of detection of 4.5 x 10-11 to 2.8 x 10-9 M.  In the BLYAS assay using dihydrotestosterone as a standard, the lower limit of detection and the EC50 values were 2.5 x 10-9 M and (9.7 ± 4.6) x 10-9 M (n = 17), respectively. In both assays, bioluminescence was observed in as little as 1 hour and data was collected in 3 – 4 hours. A third strain, S. cerevisiae BLYR which produces constant bioluminescence has also been developed to measure toxicity of each chemical, demonstrated by a decrease in bioluminescence. The primary advantages of these bioluminescent assays over colorimetric-based reporter assays include ease of use, efficiency of gathering data, and potential for use of multiple assays per microtiter plate. Further, when combined with appropriate photodetection technology, they may be used for rapid, remote monitoring of industrial and municipal waste effluents carrying hormonal active agents.

John Sanseverino, Ph.D., University of Tennessee John Sanseverino is a Research Associate Professor in the Department of Microbiology and the Managing Director of the Center for Environmental Biotechnology at the University of Tennessee. Dr. Sanseverino received his Ph.D. in Molecular Biology from Lehigh University in 1989 and a Master’s degree in Microbiology from the University of New Hampshire in 1985. Dr. Sanseverino has been involved with applying new methodology for detection and monitoring biodegradation of PAHs, PCBs, and TCE in environmental samples. In recent years, he has been involved with development and application of bioluminescent bioreporters in bacteria, yeast, and mammalian cells.


[ Manuscript ] Manuscript

6th International Conference on Pharmaceuticals and Enocrine Disrupting Chemicals in Water