Degradation of aromatics

Kennedy DW, SD Aust, JA Bumpus (1990) Comparative biodegradation of aUcyl halide insecticides by the white rot fungus, Phanerochaete chrysosporium (BKM-F-1767). Appl Environ Microbiol 56 2347-2353. Khanna P, B Rajkumar, N Jothikumar (1992) Anoxygenic degradation of aromatic substances by Rhodopseu-domonas palustris. Curr Microbiol 25 63-67. 

Arene oxides can be intermediates in the bacterial transformation of aromatic compounds and initiate rearrangements (NIH shifts) (Dalton et al. 1981 Cerniglia et al. 1984 Adriaens 1994). The formation of arene oxides may plausibly provide one mechanism for the formation of nitro-substituted products during degradation of aromatic compounds when nitrate is present in the medium. This is discussed in Chapter 2. 

Taylor BF, MJ Heeb (1972) The anaerobic degradation of aromatic compounds by a denitrifying bacterium. Radioisotope and mutant studies. Arch Microbiol 83 165-171. 

Reduction is an important reaction under both aerobic and anaerobic conditions. Reductases mediate a wide variety of reactions that are summarized briefly here, and have been discussed in detail in Part 2 dealing with electron acceptors and further in Part 5 with metalloenzymes. The reductases that are components of the aromatic dioxygenases and that are involved in the aerobic bacterial degradation of aromatic hydrocarbons are noted parenthetically in Chapter 8, Parts 1 and 2. 

Gibson DT, JR Koch, CL Schuld, RE Kallio (1968) Oxidative degradation of aromatic hydrocarbons by microorganisms. II. Metabolism of halogenated aromatic hydrocarbons. Biochemistry 7 3795-3802. 

H-labeled substrates have been used to determine the dissipation and degradation of aromatic hydrocarbons in a contaminated aquifer plume (Thierrin et al. 1995). Its application was particularly appropriate since the site was already contaminated with the substrates. With suitable precautions, this procedure seems capable of extension to determining the presence—though not the complete structure—of metabolites, provided that the possibility of exchange reactions were taken into account. 

In a classical study, it was shown that during bacterial oxidation of benzene to catechol both atoms of oxygen came from 62 (Gibson et al. 1970). This initiated the appreciation of the role of dioxygenases in the degradation of aromatic xenobiotics, and many examples are given in Chapter 8, Parts 1 and 2. 

The degradation of aromatic compounds including hydrocarbons and phenols has attracted interest over many years, for several reasons ... 

Gibson DT, V Subramanian (1984) Microbial degradation of aromatic hydrocarbons. In Microbial degradation of organic compounds (Ed DT Gibson), pp. 181-252. Marcel Dekker Inc, New York. 

Hopper DJ (1978) Microbial degradation of aromatic hydrocarbons. In Developments in biodegradation of hydrocarbons-1 (Ed RJ Watkinson), pp. 85-112. Applied Science Publishers Ltd, London. 

Several pathways are used for the aerobic degradation of aromatic compounds with an oxygenated C2 or C3 side chain. These include acetophenones and reduced compounds that may be oxidized to acetophenones, and compounds including tropic acid, styrene, and phenylethylamine that can be metabolized to phenylacetate, which has already been discussed. 

Considerable effort has been devoted to the anaerobic degradation of aromatic compounds. It is important to note that several distinct groups of organisms are involved (a) strictly anaerobic... 

Navarro-Llorens JM, MA Patrauchan, GR Stewart, JE Davies, LD Eltis, WW Mohn (2005) Phenylacetate catabolism in Rhodococcus sp. strain RHAl a central pathway for degradation of aromatic compounds. J Bacteriol 187 4497 504. 

Since the aerobic degradation of halogenated phenols takes place by monooxygenation and is discussed in Part 2 of this chapter, it is not discussed here except to note the production of chlorocat-echols from chlorophenols and chloroanilines. Emphasis is placed on chlorinated substrates, and reference may be made to a review (Allard and Neilson 2003) for details of their brominated and iodinated analogs. The degradation of aromatic fluorinated compounds is discussed in Part 3 of this chapter. 

It has already been noted (Chapter 9, Part 4) that the degradation of aromatic sulfonates when they are used as source of carbon involves dioxygenation, whereas when they serve as a source of sulfur in the absence of snlfate, degradation takes place by monooxygenation to produce the corresponding phenol and snlfite (Kertesz 1999). 

Griebler C, M Safinowski, A Vieth, HH Richnow, RU Meckenstock (2004) Combined application of stable carbon isotope analysis and specific metabolites determination for assessing in situ degradation of aromatic hydrocarbons in a tar oil-contaminated aquifer. Environ Sci Technol 38 617-631. 

Morasch B, HH Richnow, A Vieth, B Schink, RU Meckenstock (2004) Stable isotope fractionation caused by glycyl radical enzymes during bacterial degradation of aromatic compounds. Appl Environ Microbiol 70 2935-2940. 

Morasch B, HH Richnow, B Schink, A Vieth, RU Mweckenstock (2002) Carbon and hydrogen stable isotope fractionation during aerobic bacterial degradation of aromatic hydrocarbons. Appl Environ Microbiol 68 5191-5194. 

Evans WC, G Fuchs (1988) Anaerobic degradation of aromatic compounds. Annu Rev Microbiol 42 289-317. 

P Christian, Dominick C (2001) The sonochemical degradation of aromatic and chloroaro-matic contaminants. In Mason TJ and Tiehm A (eds) Advances in sonochemistry ultrasound in environmental protection, Elsevier 6 102-103... 

These enzymes catalyze a variety of oxidative reactions in natural product biosynthesis with two C—Hhydroxylation examples shown in Figure 13.24 [72,73]. It should be noted thatC—H activation by nonheme iron oxygenases, such as aromatic dioxygenases, is an important pathway in degradation of aromatics into m-dibydrodiols, which are important chiral building blocks for chemical synthesis [74,75]. 

Rojas-Avelizapa, N. G. Cervantes-Gonzalez, E. Cruz-Camarillo, R., and Rojas-Avelizapa, L. I., Degradation of aromatic and asphaltenic fractions by Serratia liquefasciens and Bacillus sp. Bulletin of Environmental Contamination and Toxicology, 2002. 69(6) pp. 835-842. 

Decrease of toxicity after addition of adapted biomass may indicate biological degradation of aromatic amines... 

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