Unexpected presence of estrogens in culture medium supplements: subsequent metabolism by the yeast Sacchromyces cerevisiae.
We have previously shown the presence of 17 beta-estradiol in extracts of commercially prepared Saccharomyces cerevisiae ss well as the production of estradiol by yeast grown in the laboratory. In our current study, yeast grown in a chemically defined medium synthesized estradiol in only small amounts, (less than 500 pg/liter). We have analyzed a variety of media commonly used for growing yeast and found that substantial estradiol production (greater than 5 ng/liter) was obtained when yeast were grown in medium supplemented with Bacto-peptone. The peptone was shown to contain significant amounts of estrone, and the results of the experiments establish a precursor-product relationship where estrone from the medium is metabolized to estradiol by S. cerevisiae. Studies with added [3H]estrone demonstrated rapid conversion into [3H]estradiol and a 3H-labeled nonpolar estrogen derivative. The commercially obtained yeast used previously had been grown in a molasses medium. We demonstrate here that the molasses medium contains substantial amounts of estrone and estradiol. We conclude that the conversion of estrone in a culture medium to estradiol in laboratory grown yeast and estrone and estradiol present in the commercially grown yeast medium account for the majority of estradiol found in yeast.
D002851:Chromatography, High Pressure Liquid; D003470:Culture Media; D004958:Estradiol / Q000032:analysis; D004967:Estrogens / Q000378:metabolism*; D004970:Estrone / Q000032:analysis; D008965:Molasses; D010461:Peptones; D011863:Radioimmunoassay; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D013997:Time Factors
D003470:Culture Media; D004967:Estrogens; D010461:Peptones; D004970:Estrone; D004958:Estradiol