Ferments, denitrifying

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. 

Single-strand conformation polymorphism (SSCP) Wastewater bioreactors (including denitrifying and phosphate-removal system, Chinese traditional medicine wastewater treatment system, beer wastewater treatment system, fermentative biohydrogen producing system, and sulfate-reduction system) Microbial community structures, diversity and distribution in different wastewater treatment processes, and relationship between the structures and the status of processes [157]... 

Denitrifying bacteria Mn- or Fe-reducing bacteria Sulfate reducing bacteria Sulfate reducing bacteria Fermenting bacteria... 

Some prokaryotes are anaerobic heterotrophs. These include the denitrifiers, sulfate reducers, and fermenters, as well as the bacteria capable of reducing metals, such as Fe(lll) to Fe(II) and Mn(lV) to Mn(II). Because the oxidized metals are present as solids, e.g., FeOOH(s), Fe203(s), and Mn02(s), these bacteria must be in direct contact with the mineral surface and have a mechanism for transferring electrons across their cell membranes. One bacterium that appears to have such a mechanism is the facultative anaerobe Shewanella oneidensis, which produces a specific protein on its outer membrane only under anaerobic conditions when it is in direct contact with a suitable... 

DNRA bacteria can be aerobic, facultatively anaerobic or obhgately anaerobic. As a group they are unlike the denitrifying bacteria in that most species are fermentative (Bonin, 1996 Tiedje, 1988). DNRA bacteria are abundant in aerobic soils and other environments that do not favor DNRA activity per se. This suggests that they can compete with other fermentative bacteria or aerobes for carbon substrates (Tiedje, 1988). Much less is understood about the diversity and physiology of DNRA bacteria than denitrifiers, despite the fact that they are sometimes the larger of the two dissimilatory NOj" sinks (Table 7). 

Hiraishi A, Muramatsu K and Urata K (1995a) Characterization of new denitrifying Rhodobacter strains isolated from photosynthetic sludge for wastewater treatment. J Ferment Bioeng 79 39-44... 

Heterotroph (=chemoonganotroph) Oxidation of organic compounds Org. C (max. 30% CO2) Org. C Anaerobic Denitrifying bacteria Mn- or Fe-reducing bacteria Sulfate reducing bacteria Fermenting bacteria... 

Many different groups of bacteria, including Bacillus, Pseudomonas, and Thiobacillus, are capable of denitrification. The primary biochemical pathways for organic substrate oxidation by denitri-fiers are similar to that described for aerobic catabolism. Because most of the denitrifiers are facultative anaerobes, they possess a functional TCA cycle that allows them to metabolize substrates completely to carbon dioxide and water. Many denitrifiers do not produce extracellular enzymes required for hydrolysis of polymers thus, they generally rely on hydrolytic enzymes and fermenters to provide readily available substrates (Ljundahl and Erickson, 1985). 

Dissimilatory reduction of nitrate to ammonia is performed by obligate and facultative anaerobes with fermentative metabolism, including Clostridium and Bacillus species (Tiedje, 1988). These organisms, in contrast to denitrifiers, usually do not rely on nitrate as electron acceptor. Therefore, DNRA involves 8e transfer as compared to 5e transfer for denitrification, suggesting that more organic substrate can be potentially degraded by DNRA. However, nitrate availability under DNRA conditions is usually very low because much of the nitrate formed during nitrification under aerobic conditions is rapidly consumed by denitrifiers in adjacent anaerobic environments. 

A wide variety of bacteria can utilize hydrogen as an electron donor denitrifiers, iron reducers, sulfate reducers, methanogens, and halorespirators. Thus, the production of hydrogen through fermentation does not, by itself, guarantee that hydrogen will be available for halorespiration. For dechlorination to occur, halorespirators must successfully compete... 

Zhu L,Yang X, Xue C, ChenY, Qu L, Lu W. Enhanced rhamnolipids production by Pseudomonas aeruginosa based on a pH stage-controlled fed-batch fermentation process. BioresourTechnol 2012 117 208-13. Chen CC. Rhamnolipids production with denitrifying Pseudomonas aeruginosa [Ph.D. thesis].The University Of Akron 142 pages. 

Microbial dissimilatory Fe(IIl) reduction may successfully compete with various detrimental bacteria for important substrates such as hydrogen and acetate in anaerobic eco- or technical systems. By removing these substrates, Fe(III) reducers may reduce growth of known MIC-causing microorganisms like sulfate reducers, methanogens, denitrifiers, and fermentative species [14]. The protective effect was demonstrated under both aerobic and anaerobic conditions. 

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