• A number of bacteria that can degrade a variety of aromatic compounds have been identified and the pathways involved in the degradation have been extensively characterized [ 3 , 4 ]. (biomedcentral.com)
  • Peripheral enzymes, particularly oxygenases and dehydrogenases, were found to transform structurally diverse substrates into one of these central intermediates by bringing about the hydroxylation of the aromatic nucleus (Fig. 2A ), and hence it is thought that bacteria have developed these enzymes to extend their substrate range [ 5 ]. (biomedcentral.com)
  • For instance, carbon-carbon bond cleavage, fatty acid hydroperoxidation, carbon-sulfur bond cleavage, and thiol oxidation are all reactions catalyzed by mononuclear iron dioxygenases. (wikipedia.org)
  • This then allows for reaction with dioxygen and subsequent intradiol cleavage to occur through a cyclic anhydride intermediate. (wikipedia.org)
  • They play a key role in the metabolism of organic compounds by increasing their reactivity or water solubility or bringing about cleavage of the aromatic ring. (biomedcentral.com)
  • In the convergent mode, structurally diverse aromatic compounds are converted to one of a few aromatic ring cleavage substrates such as catechol, gent sate, protocatechuate and their derivatives [ 5 ]. (biomedcentral.com)
  • In this divergent mode, a metal-dependent dioxygenase channels these dihydroxylated intermediates into one of the two possible pathways: the meta -cleavage pathway or the ortho -cleavage pathway [ 7 - 9 ] (Fig. 1 ). (biomedcentral.com)
  • Oxygenases belong to the oxidoreductive group of enzymes (E.C. Class 1), which oxidize the substrates by transferring oxygen from molecular oxygen (O 2 ) and utilize FAD/NADH/NADPH as the co-substrate. (biomedcentral.com)
  • Dioxygenases are oxidoreductase enzymes. (wikipedia.org)
  • The catechol dioxygenases, some of the most well-studied dioxygenase enzymes, use dioxygen to cleave a carbon-carbon bond of an aromatic catechol ring system. (wikipedia.org)
  • Intradiol enzymes cleave the carbon-carbon bond between the two hydroxyl groups. (wikipedia.org)
  • The analysis of both the metagenome of the consortium and the reconstructed metagenome-assembled genomes show that the most abundant bacterial genus in the consortium, Acidocella , possess many of the genes required for the degradation of diesel fuel aromatic hydrocarbons, which are often the most toxic component. (springeropen.com)
  • Many of these compounds have been reported to be toxic to the living organisms [ 3 ]. (biomedcentral.com)
  • The mononuclear iron dioxygenases, or non-heme iron-dependent dioxygenases as they are also termed, all utilize a single catalytic iron to incorporate either one or both atoms of dioxygen into a substrate. (wikipedia.org)
  • Extradiol members utilize ferrous iron as the active redox state, and this center is commonly coordinated octahedrally through a 2-His-1-Glu motif with labile water ligands occupying empty positions. (wikipedia.org)
  • Iron-containing dioxygenases can be subdivided into three classes on the basis of how iron is incorporated into the active site: those employing a mononuclear iron center, those containing a Rieske [2Fe-2S] cluster, and those utilizing a heme prosthetic group. (wikipedia.org)
  • Oxygenases can further be grouped into two categories i.e. monooxygenases and dioxygenases on the basis of number of oxygen atoms used for oxidation. (biomedcentral.com)
  • Despite this common oxygenation event, the mononuclear iron dioxygenases are diverse in how dioxygen activation is used to promote certain chemical reactions. (wikipedia.org)
  • The dioxygenases (EC 1.13.11) catalyze the oxidation of a substrate without the reduction of one oxygen atom from dioxygen into a water molecule. (wikipedia.org)
  • The dioxygenases (EC 1.13.11) catalyze the oxidation of a substrate without the reduction of one oxygen atom from dioxygen into a water molecule. (wikipedia.org)
  • For instance, carbon-carbon bond cleavage, fatty acid hydroperoxidation, carbon-sulfur bond cleavage, and thiol oxidation are all reactions catalyzed by mononuclear iron dioxygenases. (wikipedia.org)
  • Advanced oxidation processes (APOs) of aromatic compounds, particularly of phenol, yield several benzene derivatives, such as hydroquinone, catechol, and resorcinol, as intermediate metabolites of its transformation. (hindawi.com)
  • The formation of hydroquinone and -benzoquinone at early stages of phenol oxidation increases the toxicity of phenol wastewaters, showing that these compounds were more toxic and less degradable than the original pollutant [ 2 ]. (hindawi.com)
  • This then allows for reaction with dioxygen and subsequent intradiol cleavage to occur through a cyclic anhydride intermediate. (wikipedia.org)
  • On the other hand, hydroquinone can be a component of high molecular aromatic compounds (e.g., resin), an intermediate, or appear as a degradation product generated by transformation of aromatic compounds. (hindawi.com)
  • Meanwhile, in the oxidative degradation of hydroquinone under a supercritical condition (409.9°C and 24.5 MPa) and subcritical condition (359.9°C and 24.5 MPa), -benzoquinone was to be an important intermediate [ 3 ]. (hindawi.com)