Amperometric detection of hormonal activity by a yeast cell biosensor The widespread use of natural and synthetic estrogens or chemicals with estrogenic activities is causing an increasing accumulation of estrogenic compounds in the environment. Already at very low concentrations these estrogenics can severely affect the wildlife particularly in an aquatic environment. For these reasons measuring devices for detecting estrogen contaminations are in great demand. The majority of the analytical methods and bioassays on the market so far lack semi online adaptability and usually cannot be used for automatic and continuous determination. Therefore we have embarked on the development of new systems which are able to fulfil those demands. The EstraMonitor combines recombinant A. adeninivorans G1212 YRC102 hERa phyK yeast cells as the microbial component with an amperometric detection method to analyze estrogenic contaminations. A. adeninivorans G1212 YRC102 hERa phyK was constructed by Kaiser et al. (2010). These cells were engineered to co express the human estrogen receptor (hERa) gene and the inducible phytase (phyK derived from Klebsiella sp. ASR1) reporter gene under control of a promoter with estrogen response elements (EREs). In the presence of estrogenic substances such as 17ß estradiol (E2) the phyK gene is expressed and recombinant phytase is secreted into the media. The level of phytase is quantified by amperometric detection ... Biosensor Hefeartige Pilze Östrogene Östrogen Rezeptor Modulator Amperometrische Detektion EstraMonitor