scholarly journals Investigations on the Degradation of the Bile Salt Cholate via the 9,10-Seco-Pathway Reveals the Formation of a Novel Recalcitrant Steroid Compound by a Side Reaction in Sphingobium sp. Strain Chol11

2021 ◽  
Vol 9 (10) ◽  
pp. 2146
Author(s):  
Franziska Maria Feller ◽  
Sebastian Eilebrecht ◽  
Ruslan Nedielkov ◽  
Onur Yücel ◽  
Julia Alvincz ◽  
...  
Keyword(s):  
Bile Salts ◽  
Agricultural Soils ◽  
Pseudomonas Stutzeri ◽  
Side Reaction ◽  
Transcriptome Profiling ◽  
Ring Closure ◽  
Soil Slurry ◽  
Unknown Compound ◽  
Hormone Responses ◽  
Steroid Skeleton

Bile salts such as cholate are steroid compounds from the digestive tracts of vertebrates, which enter the environment upon excretion, e.g., in manure. Environmental bacteria degrade bile salts aerobically via two pathway variants involving intermediates with Δ1,4- or Δ4,6-3-keto-structures of the steroid skeleton. Recent studies indicated that degradation of bile salts via Δ4,6-3-keto intermediates in Sphingobium sp. strain Chol11 proceeds via 9,10-seco cleavage of the steroid skeleton. For further elucidation, the presumptive product of this cleavage, 3,12β-dihydroxy-9,10-seco-androsta-1,3,5(10),6-tetraene-9,17-dione (DHSATD), was provided to strain Chol11 in a co-culture approach with Pseudomonas stutzeri Chol1 and as purified substrate. Strain Chol11 converted DHSATD to the so far unknown compound 4-methyl-3-deoxy-1,9,12-trihydroxyestra-1,3,5(10)7-tetraene-6,17-dione (MDTETD), presumably in a side reaction involving an unusual ring closure. MDTETD was neither degraded by strains Chol1 and Chol11 nor in enrichment cultures. Functional transcriptome profiling of zebrafish embryos after exposure to MDTETD identified a significant overrepresentation of genes linked to hormone responses. In both pathway variants, steroid degradation intermediates transiently accumulate in supernatants of laboratory cultures. Soil slurry experiments indicated that bacteria using both pathway variants were active and also released their respective intermediates into the environment. This instance could enable the formation of recalcitrant steroid metabolites by interspecies cross-feeding in agricultural soils.

scholarly journals N,N-Bis(Hexyl α-d-Acetylmannosyl) Acrylamide

Molbank ◽  
10.3390/m1255 ◽  
2021 ◽  
Vol 2021 (3) ◽  
pp. M1255
Author(s):  
Atsushi Miyagawa ◽  
Shinya Ohno ◽  
Hatsuo Yamamura
Keyword(s):  
Mass Spectrometry ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Nuclear Magnetic Resonance Spectroscopy ◽  
Side Reaction ◽  
Resonance Spectroscopy ◽  
Biological Functions ◽  
Unknown Compound ◽  
Acrylamide Monomer

Glycosyl monomers for the assembly of multivalent ligands are typically synthesized using carbohydrates with biological functions and polymerizable functional groups such as acrylamide or styrene introduced into the carbohydrate aglycon, and monomers polymerized using a radical initiator. Herein, we report the acryloylation of 6-aminohexyl α-mannoside and its conversion into the glycosyl monomer bearing an acrylamide group. The general acryloylation procedure afforded the desired N-hexyl acetylmannosyl acrylamide monomer as well as an unexpected compound with a close Rf value. The compounds were separated and analyzed by nuclear magnetic resonance spectroscopy and mass spectrometry, which revealed the unknown compound to be the bivalent N,N-bis(hexyl α-d-acetylmannosyl) acrylamide monomer, which contains two hexyl mannose units and one acrylamide group. To the best of our knowledge, this side reaction has not previously been disclosed, and may be useful for the construction of multivalent sugar ligands.

Hydrophobicity and self‐association (micellization) of bile salts with a lactone or lactam group in a steroid skeleton

2020 ◽  
Author(s):  
Mihalj Poša ◽  
Vesna Tepavčević ◽  
Ljubica Grbović ◽  
Mira Mikulić ◽  
Ksenija Pavlović
Keyword(s):  
Bile Salts ◽  
Self Association ◽  
Steroid Skeleton

Effects of bile salts and divalent cations on the adsorption of norfloxacin by agricultural soils

2014 ◽  
Vol 26 (4) ◽  
pp. 846-854 ◽  
Author(s):  
Xuesong Kong ◽  
Shixiang Feng ◽  
Xu Zhang ◽  
Yan Li
Keyword(s):  
Bile Salts ◽  
Agricultural Soils ◽  
Divalent Cations

scholarly journals Comparative analysis of bile-salt degradation in Sphingobium sp. strain Chol11 and P. stutzeri Chol1 reveals functional diversity of β-proteobacterial steroid degradation enzymes and suggests a novel reaction sequence for side-chain degradation involving a hydroxylation step

2021 ◽  
Author(s):  
Franziska Maria Feller ◽  
Phil Richtsmeier ◽  
Maximilian Wege ◽  
Bodo Philipp
Keyword(s):  
Comparative Analysis ◽  
Bile Salt ◽  
Functional Diversity ◽  
Bile Salts ◽  
Deletion Mutant ◽  
Pseudomonas Stutzeri ◽  
Degradation Pathway ◽  
Ring Cleavage ◽  
Side Chain ◽  
Reaction Sequence

The reaction sequence for aerobic degradation of bile salts by environmental bacteria resembles degradation of other steroid compounds. Recent findings show that bacteria belonging to the Sphingomonadaceae use a pathway variant for bile-salt degradation. This study addresses this so-called Δ4,6 -variant by comparative analysis of unknown degradation steps in Sphingobium sp. strain Chol11 with known reactions found in Pseudomonas stutzeri Chol1. Investigations with strain Chol11 revealed an essential function of the acyl-CoA dehydrogenase Scd4AB for growth with bile salts. Growth of the scd4AB deletion mutant was restored with a metabolite containing a double bond within the side chain which was produced by the Δ22-acyl-CoA dehydrogenase Scd1AB from P. stutzeri Chol1. Expression of scd1AB in the scd4AB deletion mutant fully restored growth with bile salts while expression of scd4AB only enabled constricted growth in P. stutzeri Chol1 scd1A or scd1B deletion mutants. Strain Chol11 Δscd4A accumulated hydroxylated steroid metabolites which were degraded and activated with coenzyme A by the wild type. Activities of five Rieske type monooxygenases of strain Chol11 were screened by heterologous expression and compared to the B-ring cleaving KshABChol1 from P. stutzeri Chol1. Three of the Chol11 enzymes catalyzed B-ring cleavage of only Δ4,6 -steroids while KshABChol1 was more versatile. Expression of a fourth KshA homolog, Nov2c228 led to production of metabolites with hydroxylations at an unknown position. These results indicate functional diversity of β-proteobacterial enzymes for bile-salt degradation and suggest a novel side-chain degradation pathway involving an essential ACAD reaction and a steroid hydroxylation step.

scholarly journals Proteome, bioinformatic and functional analyses reveal a distinct and conserved metabolic pathway for bile salt degradation in the Sphingomonadaceae

2021 ◽  
Author(s):  
Franziska Maria Feller ◽  
Lars Wöhlbrand ◽  
Johannes Holert ◽  
Vanessa Schnaars ◽  
Lea Elsner ◽  
...  
Keyword(s):  
Bile Salt ◽  
Gene Cluster ◽  
Metabolic Pathway ◽  
Bile Salts ◽  
Model Organisms ◽  
Side Chain ◽  
Putative Gene ◽  
Degrading Bacteria ◽  
Functional Analyses ◽  
Steroid Skeleton

Bile salts are amphiphilic steroids with a C5 carboxylic side chain with digestive functions in vertebrates. Upon excretion, they are degraded by environmental bacteria. Degradation of the bile-salt steroid skeleton resembles the well-studied pathway for other steroids like testosterone, while specific differences occur during side-chain degradation and the initiating transformations of the steroid skeleton. Of the latter, two variants via either Δ1,4- or Δ4,6-3-ketostructures of the steroid skeleton exist for 7-hydroxy bile salts. While the Δ1,4- variant is well-known from many model organisms, the Δ4,6-variant involving a 7-hydroxysteroid dehydratase as key enzyme has not been systematically studied. Here, combined proteomic, bioinformatic and functional analyses of the Δ4,6-variant in Sphingobium sp. strain Chol11 were performed. They revealed a degradation of the steroid rings similar to the Δ1,4-variant except for the elimination of the 7-OH as key difference. In contrast, differential production of the respective proteins revealed a putative gene cluster for side-chain degradation encoding a CoA-ligase, an acyl-CoA dehydrogenase, a Rieske monooxygenase, and an amidase, but lacking most canonical genes known from other steroid-degrading bacteria. Bioinformatic analyses predicted the Δ4,6-variant to be widespread among the Sphingomonadaceae, which was verified for three type strains which also have the predicted side-chain degradation cluster. A second amidase in the side-chain degradation gene cluster of strain Chol11 was shown to cleave conjugated bile salts while having low similarity to known bile-salt hydrolases. This study signifies members of the Sphingomonadaceae remarkably well-adapted to the utilization of bile salts via a partially distinct metabolic pathway.

scholarly journals Proteome, bioinformatic and functional analyses reveal a distinct and conserved metabolic pathway for bile salt degradation in the Sphingomonadaceae

2021 ◽  
Author(s):  
Franziska M. Feller ◽  
Lars Wöhlbrand ◽  
Johannes Holert ◽  
Vanessa Schnaars ◽  
Lea Elsner ◽  
...  
Keyword(s):  
Bile Salt ◽  
Gene Cluster ◽  
Metabolic Pathway ◽  
Bile Salts ◽  
Side Chain ◽  
Putative Gene ◽  
Degrading Bacteria ◽  
Environmental Bacteria ◽  
Functional Analyses ◽  
Steroid Skeleton

Bile salts are amphiphilic steroids chain with digestive functions in vertebrates. Upon excretion, bile salts are degraded by environmental bacteria. Degradation of the bile-salt steroid skeleton resembles the well-studied pathway for other steroids like testosterone, while specific differences occur during side-chain degradation and the initiating transformations of the steroid skeleton. Of the latter, two variants via either Δ 1,4 - or Δ 4,6 -3-ketostructures of the steroid skeleton exist for 7-hydroxy bile salts. While the Δ 1,4 - variant is well-known from many model organisms, the Δ 4,6 -variant involving a 7-hydroxysteroid dehydratase as key enzyme has not been systematically studied. Here, combined proteomic, bioinformatic and functional analyses of the Δ 4,6 -variant in Sphingobium sp. strain Chol11 were performed. They revealed a degradation of the steroid rings similar to the Δ 1,4 -variant except for the elimination of the 7-OH as a key difference. In contrast, differential production of the respective proteins revealed a putative gene cluster degradation of the C 5 carboxylic side chain encoding a CoA-ligase, an acyl-CoA dehydrogenase, a Rieske monooxygenase, and an amidase, but lacking most canonical genes known from other steroid-degrading bacteria. Bioinformatic analyses predicted the Δ 4,6 -variant to be widespread among the Sphingomonadaceae , which was verified for three type strains which also have the predicted side-chain degradation cluster. A second amidase in the side-chain degradation gene cluster of strain Chol11 was shown to cleave conjugated bile salts while having low similarity to known bile-salt hydrolases. This study signifies members of the Sphingomonadaceae remarkably well-adapted to the utilization of bile salts via a partially distinct metabolic pathway. Importance This study highlights the biochemical diversity of bacterial degradation of steroid compounds, in particular bile salts. Furthermore, it substantiates and advances knowledge of a variant pathway for degradation of steroids by sphingomonads, a group of environmental bacteria that are well-known for their broad metabolic capabilities. Biodegradation of bile salts is a critical process due to the high input of these compounds from manure into agricultural soils and wastewater treatment plants. In addition, these results may also be relevant for the biotechnological production of bile salts or other steroid compounds with pharmaceutical functions.

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