Isolation and identification of iron-reducing bacteria from gley soils

Dissimilatory Fe(III) and Mn(IV) Reduction

“…Starkey and Halverson (289) found that Fe(III) was reduced in anaerobic cultures of Clostridium sporogenes or E. coli growing in a glucose or peptone medium, and Roberts (272) found that Bacillus polymyxa reduced Fe(III) while fermenting glucose. Subsequent studies found that a wide variety of fermentative microorganisms reduced Fe(III) or Mn(IV) during anaerobic growth (45,46,128,158,159,226,245,246), and organisms capable of reducing Fe(III) and Mn(IV) under aerobic culture conditions have also been described (76,82,86,316).…”

“…The many studies by Ottow and co-workers consistently indicated that Fe(III) in microbial cultures was only the result of direct enzymatic action (223,224,226,241,242,(244)(245)(246)248). For example, Munch and Ottow (225,226) found that B. polymyxa and Clostridium butyricum could reduce small amounts of Fe203 (hematite) during fermentation of glucose.…”

“…This phenomenon is termed gleying. Fe(III)-reducing fermentative bacteria have been isolated from gleyed soils (46,245,246), and artificially gleyed soils have been generated by stimulating microbial Fe(III) reduction (7,36,243,245). It has also been suggested that soil gleying could, at least in part, be the result of dissolved organic compounds abiologically reducing Fe(III) in the soil (37).…”

“…The form of the Mn(IV) oxides is also likely to affect the rate and extent of Mn(IV) reduction, but this does not appear to have been investigated systematically. Some Fe(III)-reducing microorganisms grown on complex medium reduced highly crystalline Fe(III) oxide forms such as hematite (Fe2O3) and goethite (a-FeOOH) (11,76,128,155,226,245,246,256,320). In contrast, with acetate as the electron acceptor, GS-15 could only actively reduce (within 4 days) natural or synthetic poorly crystalline Fe(III) oxides (198).…”

Iron-Reducing Bacteria and Iron Nanostructures

“…From gram staining point of view IRB are not restricted in one category and both gram-positive and gram-negative bacteria can be found among them [5][6][7][8][9][10]. This group of bacteria is now so divergent and belong to gamma and delta Proteobacteria including verity of genus and species such as Stenotrophomonas maltophilia, Brachymonas denitrificans, Paracolobacterum aerogenoides, Serratia marcescens, Aerobacter aerogenes, Citrobacter freundii, Bacillus circuhzns, Bacillus polymyxa, Bacillus alvei, Bacillus cereus, Bacillus pumilus, Bacillus subtilis, Bacillus cereus, Bacillus sphaericus, Pseudomonas aeruginosa, Pseudomonas denitrificans, Pseudomonas stutzeri, Pseudomonas fluorescens, and Pseudomonas putida [11][12][13].…”