Oxidization by microorganism

Sib CJ, KC Wang, HH Tai (1968) Mechanisms of steroid oxidation by microorganisms XIII. C22 acid intermediates in the degradation of the cholesterol side chain. Biochemistry 7 796-807. 

In another study (Watwood, White Dahm, 1991), benzene mineralization occurred in soils incubated under an inert gas for 4 weeks. No attempt was made to remove residual oxygen from these soils and the possibility exists that benzene mineralization may have been linked to the consumption of oxygen. Alternately, it may have been that benzene was partially oxidized by microorganisms and the resulting product was amenable to anaerobic decay. An earlier study (Van Beelen Van Keulen, 1990) showed an extremely rapid rate of benzene mineralization 2% mineralized in 1 h and 5% in 7 days. No samples were taken between 1 and 7 days and further benzene mineralization was not observed. 

Almost all fuel hydrocarbons (including benzene, toluene, ethylbenzene, and the xylene isomers (BTEX)) can be directly oxidized by microorganisms in the groundwater under aerobic conditions [25]. The following stoichiometry illustrates the direct aerobic oxidation of benzene, resulting in production of microbial cells, carbon dioxide, and water ... 

The role of sulfur- and iron-oxidizing bacteria. As already noted, the rates of FeS2 and Fe(II) oxidation in environmental systems often differ substantially from the abiotic rates. Usually natural rates are much faster than laboratory abiotic rates. The reasons include inorganic catalysis and especially enzymatic oxidation by microorganisms. Oxidation of Fe(ll), for example, is catalyzed by some clays and metals, including Al, Fe, Co +, Cu, and Mn, and also HPO (Stumm and Morgan 1981). 

Little is known with regard to any metabolic changes of inorganic thallium in humans. Biomethylation seems possible, as has been shown in a similar manner for mercury. Under environmental conditions, inorganic thallium may be oxidized by microorganisms and stabilized in the triva-lent form as dimethylthallium(III) salts (Huber and Kotulla 1982). 

Rule 1, however, has unrestricted applicability. The degradation of aromatic compounds proceeds in a much more complicated manner and cyclic compounds offer great resistance to oxidation by microorganisms. 

Payne, W. J. 1973. Reduction of nitrogenous oxides by microorganisms. Bacterial. Rev. 37 409-452. 

Mittleman and Danko [45] determined that sulfur cycling, that is, sulfate reduction and sulfide oxidation, by microorganisms... 

Reactions of this type also occur in insects but are not limited to them. Oxidation by microorganisms has been extensively studied and is often selective for certain kinds of C—H bonds. The fungus Pseudomonas oleovorans, for example, oxidizes the CH3 groups at the end of the carbon chain of 4-methyloctane faster than the CH3 branch and faster than the CH2 and CH units within the chain. 

In bioanodes, an (in)organic electron donor is oxidized by microorganisms with concomitant liberation of electrons and protons (Figure 6.1). The electrons produced are shuttled through the internal electron transport chain of the microorganisms and are deposited on the anode. The energy level of the electrons deposited on the electrode is dependent on the terminal electron transfer molecule. 

A major factor in the chemistry of the aquatic system shown in Figure 3.7 is the biochemical photosynthetic production of organic matter represented as CH2O. Organic matter is a biochemical reducing agent, and when it sinks into the hypolimnion it is oxidized by microorganism-mediated processes that, for example, reduce NO3 and 804 to NHJ and H2S, respectively. Two important microbially mediated oxidation-reduction reactions of CHjO are reaction with dissolved O2... 

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