Fermentative iron reducers

Microbiological action in starch dispersions results in a drop in pH, loss of viscosity and the development of odor. Retrogradation may be accelerated by the drop in pH or especially if butanol, which complexes with amylose, is generated via starch fermentation. Sulfate-reducing bacteria will cause black deposits due to reaction with iron in the process water. For quality control, preservatives are added to starch slurry, cooked starch, surface size and coating color. 

Iron-reducing bacterial cell Fermenting bacterial cell... 

In anaerobic archaea, ferredoxin functions as an intermediate electron acceptor of a variety of key steps in the central metabolic pathways involved in saccharolytic and peptide fermentation, and reduced ferredoxin thus formed donates its reducing equivalent to ferredoxiniNADP" oxidoreductase and hydrogenase. - In aerobic and thermoacidophilic archaea, the reoxidation steps of reduced zinc-containing ferredoxin are poorly characterized. The soluble fraction of Sulfolobus sp. strain 7 also contains an NADPH ferredoxin oxidoreductase activity, but this enzyme has not been purified and characterized. The following section describes the purification and partial characterization of a red iron-sulfur flavoprotein with a weak ferredoxin-reoxidizing activity fi om Sulfolobus sp. strain 7. ... 

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... 

Assimilation, as mentioned above, is unlikely to have an effect on corrosion as trace amounts of iron are required for it to occur, whereas dissimilatory iron reduction involves electron transfer to iron as part of both anaerobic fermentation or anaerobic respiration [40, 66, 67]. The inpact of fermentor iron reducers has not been studied in detail, perhaps because they do not reduce ferric iron as rapidly or extensively as anaerobic respitory IRB [112], However, Panter reported that fermentative IRB in submerged environments are encountered more frequently than the IRB that use ferric ion in anaerobic respiration [112]. Nonetheless, as mentioned earlier, it is not yet known whether the fermentative IRB could have a great contribution to corrosion. Most probably, then, the only remaining nominee for having an impact on corrosion would be the respiratory iron reducers. 

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