Construction and evaluation of two biosensors based on yeast transcriptional response to genotoxic chemicals.

It has been well established that essentially all microbial mutagens are rodent carcinogens, yet current mutagen detection systems are limited by their detection sensitivity. Here we report the construction of a pair of hypersensitive biosensors by optimizing both reporters and the host strain. The resulting RNR3-yEGFP and HUG1-yEGFP reporters and the septuple yeast mutant in combination with the automated protocol not only remarkably enhance the detection sensitivity, but also allow a high throughput screen of environmental genotoxins. This system is deemed much more sensitive than similar yeast and bacterium-based tests for all selected chemicals examined in this study.