Metabolism anaerobic

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 

Bacteria Using Nitrate Electron Acceptor under Anaerobic Conditions, and Anaerobic Phototrophs 

It has become clear that benzoate occupies a central position in the anaerobic degradation of both phenols and alkylated arenes such as toluene and xylenes, and that carboxylation, hydroxylation, and reductive dehydroxylation are important reactions for phenols that are discussed in Part 4 of this chapter. The simplest examples include alkylated benzenes, products from the carboxylation of napthalene and phenanthrene (Zhang and Young 1997), the decarboxylation of o-, m-, and p-phthalate under denitrifying conditions (Nozawa and Maruyama 1988), and the metabolism of phenols and anilines by carboxylation. Further illustrative examples include the following  

Under denitrifying conditions, 2-aminobenzoate is degraded by a Pseudomonas sp. to benzoate, which is then reduced to cyclohexene-l-carboxylate (Lochmeyer et al. 1992). 

The metabolism of cinnamate and w-phenylalkane carboxylates has been studied in Rhodopseudomonaspalustris (Elder et al. 1992), and for growth with the higher homologs additional CO2 was necessary. The key degradative reaction was ()-oxidation, for compounds with chain lengths of three, five, and seven carbon atoms, benzoate was formed and further metabolized, but for the even-numbered compounds with four, six, and eight carbon atoms phenylacetate was a terminal metabolite. 

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Metabolic rate (M) The rate of transformation of chemical energy into heat and mechanical work by aerobic and anaerobic metabolic activities w ithin an organism, usually expressed per unit area of the total body surface, in met or W m -. 

Lack of oxygen in blood or tissues. Tissue hypoxia can be caused by injury, inflammation, or tumor growth, due to disruption of blood supply. Tissue hypoxia is normally associated with acidosis, as anaerobic metabolism leads to production of lactic acid. 

The chemical engineering approach began with an analysis of the biochemistry of platelet metabolism. Like many cells, platelets consume glucose by two pathways, an oxidative pathway and an anaerobic pathway. The oxidative pathway produces carbon dioxide, which makes the solution containing the platelets more acidic (lower pH) and promotes anaerobic metabolism. This second metabolic pathway produces large amounts of lactic acid, further lowering pH. The drop in pH from both pathways kills the platelets. 

Molecular hydrogen plays a major role on the oxidation-reduction processes involved in bacterial energetics, as well as in the degradation and conversion of biomass related with all major elemental cycles. Hydrogenase has a key role on this process and catalyzes the reversible oxidation of dihydrogen, important in bacterial anaerobic metabolism ... 

Bowlus, R.D. Somero, G.N. (1979). Solute compatibility with enzyme function and structure rationales for the selection of osmotic agents and end products of anaerobic metabolism in marine invertebrates. Journal of Experimental Zoology, 208, 137-52. 

Lactate produced by anaerobic metabolism in skeletal muscle passes to liver, which uses it to synthesize glucose, which can then return to muscle (the Cori cycle). 

The anaerobic metabolism of phenol in T. aromatica is initiated by the ATP-dependent conversion of phenol to phenylphosphate catalyzed by phenylphosphate... 

Abeliovich A, A Vonshak (1992) Anaerobic metabolism of Nitrosomonas europaea. Arch Microbiol 158 267-270. 

Rontani J-F, MJ Gilewicz, VD Micgotey, TL Zheng, PC Bonin, J-C Bertrand (1997) Aerobic and anaerobic metabolism of 6,10,14-trimethylpentadecan-2-one by a denitrifying bacterium isolated from marine sediments. Appl Environ Microbiol 63 636-643. 

Nozawa T, Y Maruyama (1988) Anaerobic metabolism of phthalate and other aromatic compounds by a denitrifying bacterium. J Bacteriol 170 5778-5784. 

Harwood CS, G Burchardt, H Herrmann, G Fuchs (1999) Anaerobic metabolism of aromatic compounds via the benzoyl-CoA pathway. FEMS Microbiol Rev 22 439-458. 

Zhang X, LY Young (1997) Carboxylation as an initial reaction in the anaerobic metabolism of naphthalene and phenanthrene by sulfidogenic consortia. Appl Environ Microbiol 63 4759-4764. 

Rabus R, J Heider (1998) Initial reactions of anaerobic metabolism of alkylbenzenes in denitrifying and sulfate-reducing bacteria. Arch Microbiol 170 377-384. 

The anaerobic metabolism of L-phenylalanine by Thauera aromatica under denitrifying conditions involves several steps that result in the formation of benzoyl-CoA (a) conversion to the CoA-ester by a ligase, (b) transamination to phenylacetyl-CoA, (c) a-oxidation to phenylglyoxalate, and (d) decarboxylation to benzoyl-CoA (Schneider et al. 1997). 

Brackmann R, G Fuchs (1993) Enzymes of anaerobic metabolism of phenolic compounds. 4-hydroxybenzoyl-CoA reductase (dehydroxylating) from a denitrifying Pseudomonas sp. Eur J Biochem 213 563-571. 

Heider J et al. (1998) Differential induction of enzymes involved in anaerobic metabolism of aromatic compounds in the denitrifying bacterium Thauera aromatica. Arch Microbiol 170 120-131. 

Kluge C, A Tschech, G Fuchs (1990) Anaerobic metabolism of resorcylic acids (m-dihydroxybenzoates) and resorcinol (1,3-benzenediol) in a fermenting and in a denitrifying bacterium. Arch Microbiol 155 68-74. 

Laempe D, M Jahn, K Breese, H Schagger, G Euchs (2001) Anaerobic metabolism of 3-hydroxybenzoate by the denitrifying bacterium Thauera aromatica. J Bacteriol 183 968-979. 

Perrotta JA, CS Harwood (1994) Anaerobic metabolism of cyclohex-l-ene-l-carboxylate, a proposed intermediate of benzoate degradation by Rhodopseudomonas palustris. Appl Environ Microbiol 60 1775-1782. 

Breinig S, E Schiltz, G Fuchs (2000) Genes involved in anaerobic metabolism of phenol in the bacterium Thauera aromatica. J Bacterial 182 5849-5863. 

Roberts DJ, PM Fedorak, SE Hrudey (1990) COj incorporation and 4-hydroxy-2-methylbenzoic acid formation during anaerobic metabolism of m-cresol by a methanogenic consortium. Appl Environ Microbiol 56 472-478. 

There has been considerable interest in the anaerobic metabolism of methane in the large reservoirs that lie beneath the seafloor, since little of this reaches the oxic conditions in the water column. Consortia of archaea that have so far resisted isolation and sulfate-reducing bacteria have been implicated (Orphan et al. 2002) ... 

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