Integrated multi-omics analyses reveal the biochemical mechanisms and phylogenetic relevance of anaerobic androgen biodegradation in the environment
Journal
ISME Journal
Journal Volume
10
Journal Volume
10
Journal Issue
8
Journal Issue
8
Pages
1967-1983
Start Page
1967
End Page
1983
ISSN
17517362
Date Issued
2016-04-01
Author(s)
Yang, Fu-Chun
Tang, Sen-Lin
Wang, Po-Hsiang
Ismail, Wael
Wang, Chia-Hsiang
Ding, Jiun-Yan
Yang, Cheng-Yu
Yang, Chia-Ying
Chiang, Yin-Ru
Abstract
Steroid hormones, such as androgens, are common surface-water contaminants. However, literature on the ecophysiological relevance of steroid-degrading organisms in the environment, particularly in anoxic ecosystems, is extremely limited. We previously reported that Steroidobacter denitrificans anaerobically degrades androgens through the 2,3-seco pathway. In this study, the genome of Sdo. denitrificans was completely sequenced. Transcriptomic data revealed gene clusters that were distinctly expressed during anaerobic growth on testosterone. We isolated and characterized the bifunctional 1-testosterone hydratase/dehydrogenase, which is essential for anaerobic degradation of steroid A-ring. Because of apparent substrate preference of this molybdoenzyme, corresponding genes, along with the signature metabolites of the 2,3-seco pathway, were used as biomarkers to investigate androgen biodegradation in the largest sewage treatment plant in Taipei, Taiwan. Androgen metabolite analysis indicated that denitrifying bacteria in anoxic sewage use the 2,3-seco pathway to degrade androgens. Metagenomic analysis and PCR-based functional assays showed androgen degradation in anoxic sewage by Thauera spp. through the action of 1-testosterone hydratase/dehydrogenase. Our integrative 'omics' approach can be used for culture-independent investigations of the microbial degradation of structurally complex compounds where isotope-labeled substrates are not easily available.
Publisher
Nature Publishing Group
Type
journal article