Enzymes of anaerobic ethylbenzene and p-ethylphenol catabolism in 'Aromatoleum aromaticum': differentiation and differential induction.
The denitrifying bacterium 'Aromatoleum aromaticum' strain EbN1 is one of the best characterized bacteria regarding anaerobic ethylbenzene degradation. EbN1 also degrades various other aromatic and phenolic compounds in the absence of oxygen, one of them being p-ethylphenol. Despite having similar chemical structures, ethylbenzene and p-ethylphenol have been proposed to be metabolized by completely separate pathways. In this study, we established and applied biochemical and molecular biological methods to show the (almost) exclusive presence and specificity of enzymes involved in the respective degradation pathways by recording enzyme activities, complemented by heme staining, immuno- and biotin-blotting analyses. These combined results substantiated the predicted p-ethylphenol degradation pathway. The identified enzymes include a heme c-containing p-ethylphenol-hydroxylase, both an (R)- and an (S)-specific alcohol dehydrogenase as well as a novel biotin-dependent carboxylase. We also establish an activity assay for benzoylacetate-CoA ligases likely being involved in both metabolic pathways.
Laboratory of Microbial Biochemistry, Philipps University Marburg, Karl-von-Frisch-Str. 8, 35043, Marburg, Germany.
Enrico
E
Muhr
Laboratory of Microbial Biochemistry, Philipps University Marburg, Karl-von-Frisch-Str. 8, 35043, Marburg, Germany.
Karola
K
Schühle
Laboratory of Microbial Biochemistry, Philipps University Marburg, Karl-von-Frisch-Str. 8, 35043, Marburg, Germany.
Lina
L
Clermont
Laboratory of Microbial Biochemistry, Philipps University Marburg, Karl-von-Frisch-Str. 8, 35043, Marburg, Germany.
Katharina
K
Sünwoldt
Laboratory of Microbial Biochemistry, Philipps University Marburg, Karl-von-Frisch-Str. 8, 35043, Marburg, Germany.|LOEWE-Center for Synthetic Microbiology, Philipps University Marburg, Karl-von-Frisch-Str. 8, 35043, Marburg, Germany.
Daniel
D
Kleinsorge
Laboratory of Microbial Biochemistry, Philipps University Marburg, Karl-von-Frisch-Str. 8, 35043, Marburg, Germany.
Deniz
D
Seyhan
Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Str. 10, 35043, Marburg, Germany.
Jörg
J
Kahnt
Laboratory of Microbial Biochemistry, Philipps University Marburg, Karl-von-Frisch-Str. 8, 35043, Marburg, Germany.
Iris
I
Schall
Laboratory of Microbial Biochemistry, Philipps University Marburg, Karl-von-Frisch-Str. 8, 35043, Marburg, Germany.
Paul R
PR
Cordero
Laboratory of Microbial Biochemistry, Philipps University Marburg, Karl-von-Frisch-Str. 8, 35043, Marburg, Germany.
Georg
G
Schmitt
Laboratory of Microbial Biochemistry, Philipps University Marburg, Karl-von-Frisch-Str. 8, 35043, Marburg, Germany. heider@staff.uni-marburg.de.|LOEWE-Center for Synthetic Microbiology, Philipps University Marburg, Karl-von-Frisch-Str. 8, 35043, Marburg, Germany. heider@staff.uni-marburg.de.
Johann
J
Heider
D000693:Anaerobiosis; D001555:Benzene Derivatives / Q000378:metabolism*; D004790:Enzyme Induction; D053858:Metabolic Networks and Pathways; D006899:Mixed Function Oxygenases / Q000235:genetics / Q000378:metabolism*; D010636:Phenols / Q000378:metabolism*; D043362:Rhodocyclaceae / Q000201:enzymology* / Q000235:genetics
D001555:Benzene Derivatives; D010636:Phenols; C042291:4-ethylphenol; D006899:Mixed Function Oxygenases; C004912:ethylbenzene
Anaerobic catabolic pathways; Carboxylation; Ethylbenzene; Ethylphenol; Hydroxylation