scholarly journals Microbial metabolism of the pyridine ring. Metabolism of 2- and 3-hydroxypyridines by the maleamate pathway in Achromobacter sp

1974 ◽  
Vol 140 (2) ◽  
pp. 293-300 ◽  
Author(s):  
Ronald B. Cain ◽  
Charles Houghton ◽  
Keith A. Wright
Keyword(s):  
Pyridine Ring ◽  
Chelating Agents ◽  
Cleavage Product ◽  
Ring Cleavage ◽  
Growth Substrate ◽  
Specific Requirement ◽  
Heat Treated ◽  
C And N ◽  
Achromobacter Sp ◽  
Do So

1. Washed suspensions of two Achromobacter species (G2 and 2L), capable of growth upon 2- and 3-hydroxypyridine respectively as sources of C and N, rapidly oxidized their growth substrate pyridine-2,5-diol (2,5-dihydroxypyridine) and the putative ring-cleavage product maleamate without a lag. Suspensions derived from fumarate plus (NH4)2SO4 cultures were unable to do so. 2. Extracts of both bacteria oxidized pyridine-2,5-diol with the stoicheiometry of an oxygenase forming 1mol of NH3/mol of substrate. 3. Heat-treated extracts, however, formed maleamate and formate with little free NH3. 4. The conversion of maleamate into maleate plus NH3 by extracts of strain 2L, fractionated with (NH4)2SO4, and the metabolism of maleamate and maleate to fumarate by extracts of both strains demonstrated the existence of the enzymes catalysing each reaction of the maleamate pathway in these bacteria. 5. The pyridine-2,5-diol dioxygenase (mol.wt. approx. 340000) in extracts of these Achromobacter species required Fe2+ (1.7μm) to restore full activity after dialysis or treatment with chelating agents; the enzyme from strain 2L also had a specific requirement for l-cysteine (6.7mm), which could not be replaced by GSH or dithiothreitol. 6. The oxygenase was strongly inhibited in a competitive manner by the isomeric pyridine-2,3- and -3,4-diols.

scholarly journals Microbial degradation of alkylbenzenesulphonates. Metabolism of homologues of short alkyl-chain length by an Alcaligenes sp

1974 ◽  
Vol 140 (2) ◽  
pp. 121-134 ◽  
Author(s):  
J. Anthony Bird ◽  
Ronald B. Cain
Keyword(s):  
Alkyl Chain ◽  
Sole Source ◽  
Oxidation Products ◽  
Ring Cleavage ◽  
Growth Substrate ◽  
First Order ◽  
Heat Treated ◽  
Catechol 1,2 Dioxygenase ◽  
Benzene Toluene ◽  
Ortho Pathway

1. An organism isolated from sewage and identified as an Alcaligenes sp. utilized benzenesulphonate, toluene-p-sulphonate or phenylethane-p-sulphonate as sole source of carbon and energy for growth. Higher alkylbenzenesulphonate homologues and the hydrocarbons, benzene, toluene, phenylethane and 1-phenyldodecane were not utilized. 2. 2-Phenylpropanesulphonate was metabolized to 4-isopropylcatechol. 3. 1-Phenylpropanesulphonate was metabolized to an ortho-diol, which was tentatively identified, in the absence of an authentic specimen, as 4-n-propylcatechol. 4. In the presence of 4-isopropylcatechol, which inhibited catechol 2,3-dioxygenase, 4-ethylcatechol accumulated in cultures growing on phenylethane-p-sulphonate. 5. Authentic samples of catechol, 3-methylcatechol, 4-methylcatechol, 4-ethylcatechol and 3-isopropylcatechol were oxidized by heat-treated extracts to the corresponding 2-hydroxyalkylmuconic semialdehydes. Ring cleavage occurred between C-2 and C-3. 6. The catechol derived from 1-phenylpropanesulphonate was oxygenated by catechol 2,3-dioxygenase to a compound with all the properties of a 2-hydroxyalkylmuconic semialdehyde, but it was not rigorously identified. 7. The catechol 2,3-dioxygenase induced by growth on benzenesulphonate, toluene-p-sulphonate or phenylethane-p-sulphonate showed a constant ratio of specific activities with catechol, 3-methylcatechol, 4-methylcatechol and 4-ethylcatechol that was independent of the growth substrate. At 60°C, activity towards these substrates declined at an identical first-order rate. 8. Enzymes of the ‘ortho’ pathway of catechol metabolism were present in small amounts in cells grown on benzenesulphonate, toluene-p-sulphonate or phenylethane-p-sulphonate. 9. The catechol 1,2-dioxygenase oxidized the alkylcatechols, but the rates and the total extents of oxidation were less than for catechol itself. The oxidation products of these alkylcatechols were not further metabolized.

scholarly journals Aromatic Hydroxylation of Indan by o-Xylene-Degrading Rhodococcus sp. Strain DK17

2009 ◽  
Vol 76 (1) ◽  
pp. 375-377 ◽  
Author(s):  
Dockyu Kim ◽  
Choong Hwan Lee ◽  
Jung Nam Choi ◽  
Ki Young Choi ◽  
Gerben J. Zylstra ◽  
...  
Keyword(s):  
Reverse Transcription ◽  
Ring Cleavage ◽  
Growth Substrate ◽  
Aromatic Moiety ◽  
Reverse Transcription Pcr ◽  
Aromatic Hydroxylation ◽  
Rhodococcus Sp

ABSTRACT The metabolically versatile Rhodococcus sp. strain DK17 utilizes indan as a growth substrate via the o-xylene pathway. Metabolite and reverse transcription-PCR analyses indicate that o-xylene dioxygenase hydroxylates indan at the 4,5 position of the aromatic moiety to form cis-indan-4,5-dihydrodiol, which is dehydrogenated to 4,5-indandiol by a dehydrogenase. 4,5-Indandiol undergoes ring cleavage by a meta-cleavage dioxygenase.

Differential Roles of Three Different Upper Pathway Meta Ring Cleavage Product Hydrolases in the Degradation of Dibenzo- p -dioxin and Dibenzofuran by Sphingomonas wittichii RW1

2021 ◽  
Author(s):  
Thamer Y. Mutter ◽  
Gerben J. Zylstra
Keyword(s):  
Gene Knockout ◽  
Sole Source ◽  
Cleavage Product ◽  
Ring Cleavage ◽  
Catabolic Pathway ◽  
Double Knockout ◽  
Cleavage Enzyme ◽  
Sphingomonas Wittichii ◽  
Physiological Approach

Sphingomonas wittichii RW1 grows on the two related compounds dibenzofuran (DBF) and dibenzo- p -dioxin (DXN) as the sole source of carbon. Previous work by others (P.V. Bunz, R. Falchetto, and A.M. Cook. Biodegradation 4:171-8, 1993, doi: 10.1007/BF00695119) identified two upper pathway meta cleavage product hydrolases (DxnB1 and DxnB2) active on the DBF upper pathway metabolite 2-hydroxy-6-oxo-6-(2-hydroxyphenyl)-hexa-2,4-dienoate. We took a physiological approach to determine the role of these two enzymes in the degradation of DBF and DXN by RW1. Single knockouts of either plasmid located dbfB1 or chromosome located dbfB2 had no effect on RW1 growth on either DBF or DXN. However, a double knockout lost the ability to grow on DBF but still grew normally on DXN demonstrating that DbfB1 and DbfB2 are the only hydrolases involved in the DBF upper pathway. Using a transcriptomic-guided approach we identified a constitutively expressed third hydrolase encoded by the chromosomally located SWIT0910 gene. Knockout of SWIT0910 resulted in a strain that no longer grows on DXN but still grows normally on DBF. Thus the DbfB1 and DbfB2 hydrolases function in the DBF but not the DXN catabolic pathway and the SWIT0190 hydrolase functions in the DXN but not the DBF catabolic pathway. Importance S. wittichii RW1 is one of only a few strains known to grow on DXN as the sole course of carbon. Much of the work deciphering the related RW1 DXN and DBF catabolic pathways has involved genome gazing, transcriptomics, proteomics, heterologous expression, and enzyme purification and characterization. Very little research has utilized physiological techniques to precisely dissect the genes and enzymes involved in DBF and DXN degradation. Previous work by others identified and extensively characterized two RW1 upper pathway hydrolases. Our present work demonstrates that these two enzymes are involved in DBF but not DXN degradation. In addition, our work identified a third constitutively expressed hydrolase that is involved in DXN but not DBF degradation. Combined with our previous work, this means that the RW1 DXN upper pathway involves genes from three very different locations in the genome: an initial plasmid-encoded dioxygenase and a ring cleavage enzyme and hydrolase encoded on opposite sides of the chromosome.

A New Intermediate in the Mineralization of 3,4-Dichloroaniline by the White Rot FungusPhanerochaete chrysosporium

1998 ◽  
Vol 64 (9) ◽  
pp. 3305-3312 ◽  
Author(s):  
Heinrich Sandermann ◽  
Werner Heller ◽  
Norbert Hertkorn ◽  
Enamul Hoque ◽  
Dietmar Pieper ◽  
...  
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Mass Spectroscopy ◽  
High Performance ◽  
Culture Media ◽  
White Rot ◽  
Ring Cleavage ◽  
Resonance Spectroscopy ◽  
Dead End ◽  
C And N

ABSTRACT Phanerochaete chrysosporium ATCC 34541 has been reported to be unable to mineralize 3,4-dichloroaniline (DCA). However, high mineralization is now shown to occur when a fermentation temperature of 37° and gassing with oxygen are used. Mineralization did not correlate with lignin peroxidase activity. The latter was high under C limitation and low under N limitation, whereas the reverse was true for mineralization. The kinetics of DCA metabolism was studied in low-N and low-C and C- and N-rich culture media by metabolite analysis and 14CO2determination. In all cases, DCA disappeared within 2 days, and a novel highly polar conjugate termed DCAX accumulated in the growth medium. This metabolite was a dead-end product under C and N enrichment. In oxygenated low-C medium and in much higher yield in oxygenated low-N medium, DCAX was converted to DCA-succinimide and then mineralized. DCAX was purified by high-performance liquid chromatography and identified asN-(3,4-dichlorophenyl)-α-ketoglutaryl-δ-amide by high-performance liquid chromatography and mass spectroscopy, gas chromatography and mass spectroscopy, and nuclear magnetic resonance spectroscopy. The formation of conjugate intermediates is proposed to facilitate mineralization because the sensitive amino group of DCA needs protection so that ring cleavage rather than oligomerization can occur.

Degradation of phenanthrene and naphthalene by aBurkholderiaspecies strain

2003 ◽  
Vol 49 (2) ◽  
pp. 139-144 ◽  
Author(s):  
H Kang ◽  
S Y Hwang ◽  
Y M Kim ◽  
E Kim ◽  
Y -S Kim ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Energy Source ◽  
Enzyme Assay ◽  
Gas Chromatography Mass Spectrometry ◽  
Ring Cleavage ◽  
Growth Substrate ◽  
Degrading Bacteria ◽  
Subsequent Degradation ◽  
Cleavage Enzyme ◽  
Uv Visible

Burkholderia sp. TNFYE-5 was isolated from soil for the ability to grow on phenanthrene as sole carbon and energy source. Unlike most other phenanthrene-degrading bacteria, TNFYE-5 was unable to grow on naphthalene. Growth substrate range experiments coupled with the ring-cleavage enzyme assay data suggest that TNFYE-5 initially metabolizes phenanthrene to 1-hydroxy-2-naphthoate with subsequent degradation through the phthalate and protocatechuate and β-ketoadipate pathway. A metabolite in the degradation of naphthalene by TNFYE-5 was isolated by high-pressure liquid chromatography (HPLC) and was identified as salicylate by UV-visible spectral and gas chromatography – mass spectrometry analyses. Thus, the inability to degrade salicylate is apparently one major reason for the incapability of TNFYE-5 to grow on naphthalene.Key words: Burkholderia, phenanthrene, naphthalene, phthalate, protocatechuate.

Raman and Energy Dispersive Spectroscopy (EDS) Analyses of a Microsubstance Adhering to a Fiber of the Turin Shroud

2017 ◽  
Vol 71 (10) ◽  
pp. 2313-2324
Author(s):  
Jean-Pierre Laude ◽  
Giulio Fanti
Keyword(s):  
Energy Dispersive Spectroscopy ◽  
Blood Cells ◽  
Degradation Products ◽  
Cleavage Product ◽  
Energy Dispersive ◽  
Ring Cleavage ◽  
Raman Spectrometry ◽  
Blood Stains ◽  
Eds Analysis ◽  
Shroud Of Turin

The Raman spectrum of a microsubstance, smeared on a fiber coming from the Shroud of Turin, was compared with numerous spectra published for old or modern pigment dyes, whole bloods, dried bloods, red blood cells, albumin, very ancient blood stains, and various “degradation” products of heme. Within the wavenumber measure accuracy, it is shown that all Raman lines detected above background could correspond to vibration frequencies found in biliverdin-derived compounds except a weak line that we tentatively attributed to amide I. Biliverdin is known as an oxidative ring cleavage product of the heme of blood. Energy dispersive spectroscopy (EDS) analysis of the sample confirms an elemental composition fully compatible with this hypothesis. Therefore, it is very likely that this microsubstance contains products of heme including heme/biliverdin-derived compounds and protein traces (amide I). Nevertheless, other measures will be necessary to confirm it. This method of identification, adding EDS to Raman spectrometry can be applied to nondestructive testing (NDT) of many other microsamples.

scholarly journals Bacterial metabolism of 5-aminosalicylic acid. Initial ring cleavage

1992 ◽  
Vol 282 (3) ◽  
pp. 675-680 ◽  
Author(s):  
A Stolz ◽  
B Nörtemann ◽  
H J Knackmuss
Keyword(s):  
Bacterial Metabolism ◽  
Ring Cleavage ◽  
Pseudomonas Sp ◽  
Growth Substrate ◽  
Aminosalicylic Acid ◽  
Intact Cells ◽  
Cell Extracts ◽  
Ring Fission ◽  
Stoichiometric Reaction ◽  
Neutral Conditions

The metabolism of 5-aminosalicylate (5AS) by a bacterial strain, Pseudomonas sp. BN9, was studied. Intact cells of Pseudomonas sp. BN9 grown with 5AS oxidized 5AS and 2,5-dihydroxybenzoate (gentisate), whereas cells grown with gentisate oxidized only the growth substrate of all substituted salicylates tested. Cell extracts from Pseudomonas sp. BN9 catalysed the stoichiometric reaction of 1 mol of oxygen with 1 mol of 5AS to a metabolite with an intense u.v.-absorption maximum at 352 nm (pH 8.0). This metabolite was accumulated under neutral conditions, but was rapidly destroyed at acid pH. It was identified by m.s. and acid-catalysed deamination to fumarylpyruvate (trans-2,4-dioxohept-5-enedioic acid) as cis-4-amino-6-carboxy-2-oxohexa-3,5-dienoate, thus demonstrating direct cleavage of the monohydroxylated substrate 5AS to a non-aromatic ring-fission product. The enzyme responsible for conversion of 5AS was shown to be Fe(II)-dependent and to be distinct from gentisate 1,2-dioxygenase in strain BN9.

Sign in / Sign up

Export Citation Format

Share Document