TY - JOUR

T1 - Iron and carbon metabolism by a mineral-oxidizing Alicyclobacillus-like bacterium

AU - Yahya, Adibah

AU - Hallberg, Kevin B

AU - Johnson, D Barrie

PY - 2007/11/15

Y1 - 2007/11/15

N2 - A novel iron-oxidizing, moderately thermophilic, acidophilic bacterium (strain "GSM") was isolated from mineral spoil taken from a gold mine in Montana. Biomolecular analysis showed that it was most closely related to Alicyclobacillus tolerans, although the two bacteria differed in some key respects, including the absence (in strain GSM) of varpi-alicyclic fatty acids and in their chromosomal base compositions. Isolate GSM was able to grow in oxygen-free media using ferric iron as terminal electron acceptor confirming that it was a facultative anaerobe, a trait not previously described in Alicyclobacillus spp.. The acidophile used both organic and inorganic sources of energy and carbon, although growth and iron oxidation by isolate GSM was uncoupled in media that contained both fructose and ferrous iron. Fructose utilization suppressed iron oxidation, and oxidation of ferrous iron occurred only when fructose was depleted. In contrast, fructose catabolism was suppressed when bacteria were harvested while actively oxidizing iron, suggesting that both ferrous iron- and fructose-oxidation are inducible in this acidophile. Isolate GSM accelerated the oxidative dissolution of pyrite in liquid media either free of, or amended with, organic carbon, although redox potentials were significantly different in these media. The potential of this isolate for commercial mineral processing is discussed.

AB - A novel iron-oxidizing, moderately thermophilic, acidophilic bacterium (strain "GSM") was isolated from mineral spoil taken from a gold mine in Montana. Biomolecular analysis showed that it was most closely related to Alicyclobacillus tolerans, although the two bacteria differed in some key respects, including the absence (in strain GSM) of varpi-alicyclic fatty acids and in their chromosomal base compositions. Isolate GSM was able to grow in oxygen-free media using ferric iron as terminal electron acceptor confirming that it was a facultative anaerobe, a trait not previously described in Alicyclobacillus spp.. The acidophile used both organic and inorganic sources of energy and carbon, although growth and iron oxidation by isolate GSM was uncoupled in media that contained both fructose and ferrous iron. Fructose utilization suppressed iron oxidation, and oxidation of ferrous iron occurred only when fructose was depleted. In contrast, fructose catabolism was suppressed when bacteria were harvested while actively oxidizing iron, suggesting that both ferrous iron- and fructose-oxidation are inducible in this acidophile. Isolate GSM accelerated the oxidative dissolution of pyrite in liquid media either free of, or amended with, organic carbon, although redox potentials were significantly different in these media. The potential of this isolate for commercial mineral processing is discussed.

KW - Bacteria/classification

KW - Carbon Dioxide/metabolism

KW - Heterotrophic Processes

KW - Iron/metabolism

KW - Iron Compounds/metabolism

KW - Minerals/metabolism

KW - Mining

KW - Oxidation-Reduction

KW - Phylogeny

KW - Soil Microbiology

KW - Sulfides/metabolism

KW - Sulfur/metabolism

U2 - 10.1007/s00203-007-0319-5

DO - 10.1007/s00203-007-0319-5

M3 - Article

C2 - 18004545

VL - 189

SP - 305

EP - 312

JO - Archives of Microbiology

JF - Archives of Microbiology

SN - 0302-8933

IS - 4

ER -