Estrogenic Activity of Surfactants and Some of Their Degradation Products Assessed Using a Recombinant Yeast Screen

Abstract

Abstract-An estrogen-inducible screen was developed in yeast (Saccharomyces cerevisiae) in order to assess whether surfactants and their major degradation products are estrogenic. The DNA sequence of the human estrogen receptor (hER) was integrated into the yeast genome, which also contained expression plasmids carrying estrogen-responsive sequences (ERE) controlling the expression of the reporter gene lac-Z (encoding the enzyme ␤-galactosidase). Thus, in the presence of estrogens, ␤-galactosidase is synthesized and secreted into the medium, where it causes a color change from yellow to red. This recombinant strain was used to determine whether representatives of major surfactant classes and some of their principal degradation products possess estrogenic activity. The results were compared to the effects of the main natural estrogen 17␤-estradiol. None of the parent surfactants tested possessed estrogenic activity. However, one class of surfactants, the alkylphenol polyethoxylates, degrade to persistent metabolites that were weakly estrogenic. Another group of degradation products, the sulfophenyl carboxylates, which are derived from the biodegradation of linear alkylbenzene sulfonates, do not appear to possess estrogenic activity.

Monitoring of selected estrogenic compounds and estrogenic activity in surface water and sediment of the Yellow River in China using combined chemical and biological tools

“…The estrogenicity of the samples was determined by using in vitro yeast estrogen screen (YES) bioassay (Routledge and Sumpter, 1996). Briefly, certain yeast from the yeast stock stored at À20 C was added to the growth medium and grown on an orbital shaker for about 24 h until an absorption level (optical density) of 1.0 at 620 nm was achieved.…”

“…Several in vitro bioassays (e.g. E-SCREEN, yeast estrogen screen (YES), estrogen responsive chemically activated luciferase (ER-CALUX) and RTG-2 reporter gene assay) have been developed for determination of the hormonal activity of individual compounds and environmental samples (Ackermann et al, 2002;Legler et al, 2002;Routledge and Sumpter, 1996;Soto et al, 1995). Bioassays in combination with chemical analysis are valuable in not only identifying compounds affecting wildlife adversely but also evaluating the causal links of compounds in the environment by quantifying their proportion of the total estrogenic activity in samples.…”

Estrogenic activity of tropical fish food can alter baseline vitellogenin concentrations in male fathead minnow (Pimephales promelas)

“…Samples were stored at 4 o C until tested for oestrogenicity using the yeast oestrogen screen (YES assay; [34]). Each sample was tested in duplicate and every assay was carried out at least twice.…”

“…A negative control without the addition of fish food and an oestradiol-spiked positive control were also included. Samples were stored at 4 o C until tested for oestrogenicity using the YES assay [34]. Each sample was tested in duplicate and every assay was carried out at least twice.…”

Assessment of hormonal activities and genotoxicity of industrial effluents using in vitro bioassays combined with chemical analysis

“…Among these bioassays, the umu/SOS assay, a sensitive in vitro method for genotoxicity screening, has been increasingly applied to rapid screening of mutagens and carcinogens in environmental samples [24][25][26][27]. As for endocrinedisrupting effects, some in vitro bioassays, such as estrogen screen (E-SCREEN), yeast estrogen screen (YES), and estrogen-responsive chemically activated luciferase, have been developed to evaluate integrated estrogenic activity of environmental samples [28][29][30]. At the same time, in vitro bioassays such as androgen screen (A-SCREEN) [31,32], yeast androgen screen (YAS) [33], and androgen receptor (AR) binding assays [34,35], have also been developed to assess the androgenic activity of environmental samples [36].…”