Entwicklung neuer Testsysteme zur Erfassung östrogener und androgener Wirkungen im Rahmen der Umweltanalytik Endokrin wirksamer Stoff Biosensor Hormonrezeptor Phytase Rekombinantes Protein Anreicherung Arxula adeninivorans Escherichia coli Endokrine Disruptoren Arxula adeninivorans yeast androgen screen Assay (A YAS Assay) in vitro Bioassay Ligandenbindungsdomäne endocrine disrupting chemicals ligand binding domain An array of pollutants which act as endocrine disrupting chemicals (EDCs) are released into the environment and can cause changes in the development and function of the endocrine system of humans and animals. EDCs are often present in low abundance but physiologically effective concentrations and occur also as mixtures of substances in complex environmental samples. The development of new efficient user friendly and highly sensitive detection methods is required for the detection of these environmental chemicals. The aim of this work was the development and validation of two new bioanalytical assays to determine the biological potential of EDCs with high reliability. The first in vitro bioassay the new Arxula adeninivorans yeast androgen screen (A YAS) allows the detection of (anti) androgenic activities of EDCs as pure substances and in environmental samples. The A YAS assay is based on transgenic A. adeninivorans cells which constitutively express the gene of the human androgen receptor (hAR). The inducible gene of the reporter protein phytase K (phyK derived from Klebsiella sp. ASR1) is under the control of the Arxula derived glucoamylase (GAA) promoter which was modified by the insertion of hormone responsive elements (HRE). In the presence of (anti) androgenic active substances a dimer of the hAR ligand complex binds to the HRE sequences and regulates the reporter gene expression resulting in the secretion of the reporter protein phytase K into the medium ...