Other Anaerobic Bacteria

It is appropriate to mention briefly some additional reactions that are brought about by anaerobic bacteria  

Particnlarly extensive effort has been directed to the anaerobic dechlorination of alkenes and halogenated phenols that are discussed in Chapter 7, Part 3 and Chapter 9, Part 2. As a resnlt of this, the range of organisms that are able to carry this ont is considerable and inclndes 

Although they have not been obtained in pure culture, chemolithotrophic anaerobic bacteria (anammox) that oxidize ammonia using nitrite as electron donor and CO2 as a source of carbon have been described. In addition, they can oxidize propionate to CO2 (Giiven et al. 2005) by a pathway that has not yet been resolved. 

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Although Rbr and Rbo are located on separate operons in D. vulgaris, genes encoding Rbo- and Rbr-Uke proteins are located within what appear to be the same operon or gene cluster in several other anaerobic bacteria... 

Rubredoxins have been isolated from other anaerobic bacteria such as Desulfovibrio gigas (14) and Peptostreptococcus elsdenii (15) but these rubredoxins have not been examined to the same extent as those described above. 

The excreted end-products of fermentations, including hydrogen gas, can be used by other anaerobic bacteria, and what is known as an anaerobic food chain develops. At the bottom of the food chain are the archaeal methanogens, different species of which convert hydrogen gas, carbon dioxide, or acetate to CH4. The process of methanogenesis from H2 and C02 occurs as follows ... 

Actinomycosis. The anaerobe Actinomyces israelii is sensitive to several drugs, but not metronidazole, and access is poor because of granulomatous fibrosis. High doses of benzylpenicillin or amoxicillin are given for several weeks the infections are often mixed with other anaerobic bacteria so metronidazole is often given in addition to ensure activity against all components of the mixture. Co-amoxiclav may be a convenient alternative. Surgery is likely to be needed. 

In water bacteria use oxidation-reduction reactions to obtain the energy that they need for their own growth and reproduction. Some bacteria require oxygen for their metabolic needs and are called aerobic bacteria. Other anaerobic bacteria extract their oxygen from sources such as N03", S042 and other matter represented as CH20. The most common bacterially mediated reaction in water is the oxidation of organic matter ... 

A form of inorganic fermentation of sulfur compounds was discovered in recent years in several sulfate reducers and other anaerobic bacteria (Bak and Cypionka 1987). These organisms may cany out a disproportionation of S , Spf - or S03 by which H S and are formed simultaneously (Eqs. 5.4 and 5.5). Disproportionation reactions have turned out to... 

Figure 9 shows the metabolic pathway with pyruvate as a source of electrons and ATP production for nitrogen fixation. Pyruvate is also a major source of electrons for nitrogenase in other anaerobic bacteria although other metabolites (e.g., formate or NADH) will also serve. 

Conrad, R., Wetter, B., 1990. Influence of temperature on energetics of hydrogen metabolism in homoacetogenic, methanogenic, and other anaerobic bacteria. Archives of Microbiology 155, 94-98. 

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