Degradation of steroids by intestinal bacteria

1. A strain of Eschehchia coli has been shown to produce oestradiol from 4androsten-3,17-dione. 2. From the same substrate a strain of Clostridium paraputrificum produced 17-methoxy-1,3,5(10)-estratriene-3-ol, the identity of which was deduced from ultra violet and fluorescence spectra, the mass spectrum of the product and its trifluoracetyl derivative, and by comparison with the products of methylation of oestradiol. 3. The conditions required for the reaction have been investigated.