Steroid degradation in Comamonas testosteroni

Abstract

Steroid degradation by Comamonas testosteroni and Nocardia restrictus have been intensively studied for the purpose of obtaining materials for steroid drug synthesis. C. testosteroni degrades side chains and converts single/double bonds of certain steroid compounds to produce androsta-1,4-diene 3,17-dione or the derivative. Following 9-hydroxylation leads to aromatization of the A-ring accompanied by cleavage of the B-ring, and aromatized A-ring is hydroxylated at C-4 position, cleaved at ∆4 by meta-cleavage, and divided into 2-hydroxyhexa-2,4-dienoic acid (A-ring) and 9,17-dioxo-1,2,3,4,10,19-hexanorandrostan-5-oic acid (B,C,D-ring) by hydrolysis.Reactions and the genes involved in the cleavage and the following degradation of the A-ring are similar to those for bacterial biphenyl degradation, and 9,17-dioxo-1,2,3,4,10,19-hexanorandrostan-5-oic acid degradation is suggested to be mainly -oxidation. Genes involved in A-ring aromatization and degradation form a gene cluster, and the genes involved in -oxidation of 9,17-dioxo-1,2,3,4,10,19-hexanorandrostan-5-oic acid also comprise a large cluster of more than 10 genes. The DNA region between these two main steroid degradation gene clusters contain 3-hydroxysteroid dehydrogenase gene, ∆5,3-ketosteroid isomerase gene, genes for inversion of an -oriented-hydroxyl group to a -oriented-hydroxyl group at C-12 position of cholic acid, and genes possibly involved in the degradation of a side chain at C-17 position of cholic acid, indicating this DNA region of more than 100kb to be a steroid degradation gene hot spot of C. testosteroni.

Integrated multi-omics analyses reveal the biochemical mechanisms and phylogenetic relevance of anaerobic androgen biodegradation in the environment

“…In the genome of C. testoteroni TA441, tesB encoding a metacleavage dioxygenase is located next to ORF1. Similar gene organization was observed in the genomes of C. testosteroni strains CNB-2 ( Figure 2c) and KF1 (Horinouchi et al, 2012). However, a tesB-like gene was not present in the chromosomes of Sdo.…”

“…Sewage treatment plants are essential in removing steroid hormones, as shown by a comparison between sewage influents and effluents . Several androgen-degrading aerobes have been isolated and characterized (Donova, 2007;Yang et al, 2011;Horinouchi et al, 2012). Among them, Comamonas testosteroni has received special attention, and catabolic intermediates, genes, and enzymes have been identified (see Horinouchi et al (2012) for a review).…”

“…Several androgen-degrading aerobes have been isolated and characterized (Donova, 2007;Yang et al, 2011;Horinouchi et al, 2012). Among them, Comamonas testosteroni has received special attention, and catabolic intermediates, genes, and enzymes have been identified (see Horinouchi et al (2012) for a review). By contrast, literature on the biochemical mechanisms and the phylogenetic diversity involved in anaerobic steroid biodegradation is extremely limited.…”

Degradation of Norgestrel by Bacteria from Activated Sludge: Comparison to Progesterone

“…This is also supported by the fact that steroid degradation by Comamonas testosteroni has been observed during steroid drug synthesis. 57 The bacteria degraded the side chains and converted the single/double bonds of some steroids to produce androsta-1,4-diene-3,17-dione (ADD) or its derivatives. 57 This further supports the detection of ADD in the biodegradation of progesterone in the present study.…”

“…57 The bacteria degraded the side chains and converted the single/double bonds of some steroids to produce androsta-1,4-diene-3,17-dione (ADD) or its derivatives. 57 This further supports the detection of ADD in the biodegradation of progesterone in the present study. Studies about the degradation of pollutants by Chryseobacterium indologenes (strain N6) were limited.…”