Bacteria and the Fate of Estrogen in the Environment.

In this issue of Cell Chemical Biology, Chen et al. (2017) report that 4-hydroxyestrone and pyridinestrone acid are intermediates in the 4,5-seco pathway of aerobic estrogen degradation by the bacterium Sphingomonas. The authors identify a gene for 4-hydroxyestrone 4,5-dioxygenase and find it to be widely distributed in diverse proteobacteria, suggesting that this pathway is environmentally significant.