title: Initial steps in anoxic testosterone degradation by Steroidobacter denitrificans.
abstract: Steroid compounds have many important physiological activities in higher organisms. Testosterone and related steroids are important environmental contaminants that disrupt the endocrine systems of animals. The degradation of steroids, especially under anoxic conditions, is challenging because of their complex chemical structure. A denitrifying gamma-proteobacterium, Steroidobacter denitrificans, able to grow anaerobically on a variety of steroids as the sole carbon and energy source was adopted as a model organism to study the anoxic degradation of testosterone. We identified the initial intermediates involved in the anoxic testosterone degradation pathway of S. denitrificans. We demonstrated that under anoxic conditions, S. denitrificans initially oxidizes testosterone to 1-dehydrotestosterone, which is then transformed to androsta-1,4-diene-3,17-dione. In addition, it seems that androst-4-en-3,17-dione can also be directly produced from testosterone by S. denitrificans cells. In general, the initial steps of anoxic testosterone degradation by S. denitrificans are similar to those of the oxic pathway demonstrated in Comamonas testosteroni.
authors.affiliation: Microbiology Laboratory, Graduate Institute of Natural Products, College of Medicine, Chang-Gung University, Taiwan.
authors.forename: Yin-Ru
authors.initials: YR
authors.lastname: Chiang
authors.affiliation: Pharmaceutics Laboratory, Graduate Institute of Natural Products, College of Medicine, Chang-Gung University, Taiwan.
authors.forename: Jia-You
authors.initials: JY
authors.lastname: Fang
authors.affiliation: Biotechnology Program, Arabian Gulf University, Al-Manamah, Kingdom of Bahrain.
authors.forename: Wael
authors.initials: W
authors.lastname: Ismail
authors.affiliation: Microbiology Laboratory, Graduate Institute of Natural Products, College of Medicine, Chang-Gung University, Taiwan.
authors.forename: Po-Hsiang
authors.initials: PH
authors.lastname: Wang
mesh_terms: D000693:Anaerobiosis; D001673:Biodegradation, Environmental; D020563:Gammaproteobacteria / Q000737:chemistry / Q000378:metabolism*; D010084:Oxidation-Reduction; D013739:Testosterone / Q000737:chemistry / Q000378:metabolism*
chemical_list: D013739:Testosterone