scholarly journals Enzymes Involved in a Novel Anaerobic Cyclohexane Carboxylic Acid Degradation Pathway

2014 ◽  
Vol 196 (20) ◽  
pp. 3667-3674 ◽  
Author(s):  
J. W. Kung ◽  
A.-K. Meier ◽  
M. Mergelsberg ◽  
M. Boll
Keyword(s):  
Carboxylic Acid ◽  
Degradation Pathway ◽  
Acid Degradation ◽  
Cyclohexane Carboxylic Acid

scholarly journals Microbiological degradation of bile acids. The preparation of some hypothetical metabolites involved in cholic acid degradation

1976 ◽  
Vol 154 (3) ◽  
pp. 577-587 ◽  
Author(s):  
S Hayakawa ◽  
Y Kanematsu ◽  
T Fujiwara ◽  
H Kako
Keyword(s):  
Fatty Acid ◽  
Carboxylic Acid ◽  
Bile Acids ◽  
Cholic Acid ◽  
Valeric Acid ◽  
Side Chain ◽  
Partial Synthesis ◽  
Arthrobacter Simplex ◽  
Acid Degradation ◽  
Oxidation Mechanisms

1. To identify the intermediates involved in the degradation of cholic acid, the further degradation of (4R)-4-[4a-(2-carboxyethyl)-3aa-hexahydro-7ab-methyl-5-oxoindan-1β-yl]valeric acid (IVa) by Arthrobacter simplex was attempted. The organism could not utilize this acid but some hypothetical intermediate metabolities of compound (IVa) were prepared for later use as reference compounds. 2. The nor homologue (IIIa) and the dinor homologue (IIIb) of compound (IVa) were prepared by exposure of 3-oxo-24-nor-5β-cholan-23-oic acid (I) and (20S)-3b-hydroxy-5-pregnene-20-carboxylic acid (II) to A. simplex respectively. These compounds correspond to the respective metabolites produced by the shortening of the valeric acid side chain of compound (IVa) in a manner analogous to the conventional fatty acid a- and b-oxidation mechanisms. Their structures were confirmed by partial synthesis. 3. The following authentic samples of reduction products of the oxodicarboxylic acids (IIIa), (IIIb) and (IVa) were also synthesized as hypothetical metabolities: (4R)-4-[3aa-hexahydro-5a-hydroxy-4a-(3-hydroxypropyl)-7ab-methylindan-1b-yl]valeric acid (Vb) and its nor homologue (VIIa) and dinor homologue (IXa);(4R)-4-[3Aaa-hexahydro-5a-hydroxy-4a-(3-hydroxypropyl)-7ab-methylindan-1b-yl]-pentan-1-ol (Vc); and their respective 5β epimers (Ve), (VIIc), (IXc) and (Vf). 4. In connexion with the non-utilization of compound (IVa) by A. simplex, the possibility that not all the metabolites formed from cholic acid by a certain micro-organism can be utilized by the same organism is considered.

scholarly journals Novel Three-Component Phenazine-1-Carboxylic Acid 1,2-Dioxygenase in Sphingomonas wittichii DP58

2017 ◽  
Vol 83 (9) ◽  
Author(s):  
Qiang Zhao ◽  
Hong-Bo Hu ◽  
Wei Wang ◽  
Xian-Qing Huang ◽  
Xue-Hong Zhang
Keyword(s):  
Carboxylic Acid ◽  
Southern China ◽  
Nitrogen Sources ◽  
Content Type ◽  
Carbon And Nitrogen ◽  
Acid Degradation ◽  
Sphingomonas Wittichii ◽  
Encoding Gene ◽  
Encoding Genes

ABSTRACT Phenazine-1-carboxylic acid, the main component of shenqinmycin, is widely used in southern China for the prevention of rice sheath blight. However, the fate of phenazine-1-carboxylic acid in soil remains uncertain. Sphingomonas wittichii DP58 can use phenazine-1-carboxylic acid as its sole carbon and nitrogen sources for growth. In this study, dioxygenase-encoding genes, pcaA1A2, were found using transcriptome analysis to be highly upregulated upon phenazine-1-carboxylic acid biodegradation. PcaA1 shares 68% amino acid sequence identity with the large oxygenase subunit of anthranilate 1,2-dioxygenase from Rhodococcus maanshanensis DSM 44675. The dioxygenase was coexpressed in Escherichia coli with its adjacent reductase-encoding gene, pcaA3, and ferredoxin-encoding gene, pcaA4, and showed phenazine-1-carboxylic acid consumption. The dioxygenase-, ferredoxin-, and reductase-encoding genes were expressed in Pseudomonas putida KT2440 or E. coli BL21, and the three recombinant proteins were purified. A phenazine-1-carboxylic acid conversion capability occurred in vitro only when all three components were present. However, P. putida KT2440 transformed with pcaA1A2 obtained phenazine-1-carboxylic acid degradation ability, suggesting that phenazine-1-carboxylic acid 1,2-dioxygenase has low specificities for its ferredoxin and reductase. This was verified by replacing PcaA3 with RedA2 in the in vitro enzyme assay. High-performance liquid chromatography–mass spectrometry (HPLC-MS) and nuclear magnetic resonance (NMR) analysis showed that phenazine-1-carboxylic acid was converted to 1,2-dihydroxyphenazine through decarboxylation and hydroxylation, indicating that PcaA1A2A3A4 constitutes the initial phenazine-1-carboxylic acid 1,2-dioxygenase. This study fills a gap in our understanding of the biodegradation of phenazine-1-carboxylic acid and illustrates a new dioxygenase for decarboxylation. IMPORTANCE Phenazine-1-carboxylic acid is widely used in southern China as a key fungicide to prevent rice sheath blight. However, the degradation characteristics of phenazine-1-carboxylic acid and the environmental consequences of the long-term application are not clear. S. wittichii DP58 can use phenazine-1-carboxylic acid as its sole carbon and nitrogen sources. In this study, a three-component dioxygenase, PcaA1A2A3A4, was determined to be the initial dioxygenase for phenazine-1-carboxylic acid degradation in S. wittichii DP58. Phenazine-1-carboxylic acid was converted to 1,2-dihydroxyphenazine through decarboxylation and hydroxylation. This finding may help us discover the pathway for phenazine-1-carboxylic acid degradation.

scholarly journals Chlorophenol Hydroxylases Encoded by Plasmid pJP4 Differentially Contribute to Chlorophenoxyacetic Acid Degradation

2006 ◽  
Vol 72 (4) ◽  
pp. 2783-2792 ◽  
Author(s):  
T. Ledger ◽  
D. H. Pieper ◽  
B. González
Keyword(s):  
Toxic Effect ◽  
Degradation Pathway ◽  
Phenoxyacetic Acid ◽  
Hydroxylase Activity ◽  
Acid Degradation ◽  
Burkholderia Xenovorans ◽  
Mutant Strains ◽  
Negative Effect ◽  
Chlorophenoxyacetic Acid ◽  
Specific Contribution

ABSTRACT Phenoxyalkanoic compounds are used worldwide as herbicides. Cupriavidus necator JMP134(pJP4) catabolizes 2,4-dichlorophenoxyacetate (2,4-D) and 4-chloro-2-methylphenoxyacetate (MCPA), using tfd functions carried on plasmid pJP4. TfdA cleaves the ether bonds of these herbicides to produce 2,4-dichlorophenol (2,4-DCP) and 4-chloro-2-methylphenol (MCP), respectively. These intermediates can be degraded by two chlorophenol hydroxylases encoded by the tfdB I and tfdB II genes to produce the respective chlorocatechols. We studied the specific contribution of each of the TfdB enzymes to the 2,4-D/MCPA degradation pathway. To accomplish this, the tfdB I and tfdB II genes were independently inactivated, and growth on each chlorophenoxyacetate and total chlorophenol hydroxylase activity were measured for the mutant strains. The phenotype of these mutants shows that both TfdB enzymes are used for growth on 2,4-D or MCPA but that TfdBI contributes to a significantly higher extent than TfdBII. Both enzymes showed similar specificity profiles, with 2,4-DCP, MCP, and 4-chlorophenol being the best substrates. An accumulation of chlorophenol was found to inhibit chlorophenoxyacetate degradation, and inactivation of the tfdB genes enhanced the toxic effect of 2,4-DCP on C. necator cells. Furthermore, increased chlorophenol production by overexpression of TfdA also had a negative effect on 2,4-D degradation by C. necator JMP134 and by a different host, Burkholderia xenovorans LB400, harboring plasmid pJP4. The results of this work indicate that codification and expression of the two tfdB genes in pJP4 are important to avoid toxic accumulations of chlorophenols during phenoxyacetic acid degradation and that a balance between chlorophenol-producing and chlorophenol-consuming reactions is necessary for growth on these compounds.

scholarly journals Analysis of Hydroxycinnamic Acid Degradation in Agrobacterium fabrum Reveals a Coenzyme A-Dependent, Beta-Oxidative Deacetylation Pathway

2014 ◽  
Vol 80 (11) ◽  
pp. 3341-3349 ◽  
Author(s):  
Tony Campillo ◽  
Sébastien Renoud ◽  
Isabelle Kerzaon ◽  
Ludovic Vial ◽  
Jessica Baude ◽  
...  
Keyword(s):  
Ferulic Acid ◽  
Protocatechuic Acid ◽  
Coenzyme A ◽  
Degradation Pathway ◽  
Hydroxycinnamic Acid ◽  
Plant Materials ◽  
Toxic Compounds ◽  
Content Type ◽  
Acid Degradation ◽  
Species Specific

ABSTRACTThe soil- and rhizosphere-inhabiting bacteriumAgrobacterium fabrum(genomospecies G8 of theAgrobacterium tumefaciensspecies complex) is known to have species-specific genes involved in ferulic acid degradation. Here, we characterized, by genetic and analytical means, intermediates of degradation as feruloyl coenzyme A (feruloyl-CoA), 4-hydroxy-3-methoxyphenyl-β-hydroxypropionyl–CoA, 4-hydroxy-3-methoxyphenyl-β-ketopropionyl–CoA, vanillic acid, and protocatechuic acid. The genesatu1416,atu1417, andatu1420have been experimentally shown to be necessary for the degradation of ferulic acid. Moreover, the genesatu1415andatu1421have been experimentally demonstrated to be essential for this degradation and are proposed to encode a phenylhydroxypropionyl-CoA dehydrogenase and a 4-hydroxy-3-methoxyphenyl-β-ketopropionic acid (HMPKP)–CoA β-keto-thiolase, respectively. We thus demonstrated that theA. fabrumhydroxycinnamic degradation pathway is an original coenzyme A-dependent β-oxidative deacetylation that could also transformp-coumaric and caffeic acids. Finally, we showed that this pathway enables the metabolism of toxic compounds from plants and their use for growth, likely providing the species an ecological advantage in hydroxycinnamic-rich environments, such as plant roots or decaying plant materials.

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