Several aerobic metabolic pathways for the degradation of benzene, toluene, ethylbenzene and xylene (BTEX), which are provided by two enzymic systems (dioxygenases and monooxygenases), have been identified. The monooxygenase attacks methyl or ethyl substituents of the aromatic ring, which are subsequently transformed by several oxidations to corresponding substituted pyrocatechols or phenylglyoxal, respectively. Alternatively, one oxygen atom may be first incorporated into aromatic ring while the second atom of the oxygen molecule is used for oxidation of either aromatic ring or a methyl group to corresponding pyrocatechols or protocatechuic acid, respectively. The dioxygenase attacks aromatic ring with the formation of 2-hydroxy-substituted compounds. Intermediates of the "upper" pathway are then mineralized by either ortho- or meta-ring cleavage ("lower" pathway). BTEX are relatively water-soluble and therefore they are often mineralized by indigenous microflora. Therefore, natural attenuation may be considered as a suitable way for the clean-up of BTEX contaminants from gasoline-contaminated soil and groundwater.

• MeSH
• aerobní bakterie enzymologie   metabolismus   MeSH
• benzen metabolismus   MeSH
• benzenové deriváty metabolismus   MeSH
• biodegradace MeSH
• toluen metabolismus   MeSH
• uhlovodíky chemie   metabolismus   MeSH
• xyleny metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• benzen MeSH
• benzenové deriváty MeSH
• ethylbenzene MeSH Prohlížeč
• toluen MeSH
• uhlovodíky MeSH
• xyleny MeSH