PMID- 18043665
OWN - NLM
STAT- MEDLINE
DCOM- 20080114
LR  - 20151013
IS  - 1751-7362 (Print)
IS  - 1751-7362 (Linking)
VI  - 1
IP  - 7
DP  - 2007 Nov
TI  - The geomicrobiology of gold.
PG  - 567-84
AB  - Microorganisms capable of actively solubilizing and precipitating gold appear to 
      play a larger role in the biogeochemical cycling of gold than previously 
      believed. Recent research suggests that bacteria and archaea are involved in 
      every step of the biogeochemical cycle of gold, from the formation of primary 
      mineralization in hydrothermal and deep subsurface systems to its solubilization, 
      dispersion and re-concentration as secondary gold under surface conditions. 
      Enzymatically catalysed precipitation of gold has been observed in thermophilic 
      and hyperthermophilic bacteria and archaea (for example, Thermotoga maritime, 
      Pyrobaculum islandicum), and their activity led to the formation of gold- and 
      silver-bearing sinters in New Zealand's hot spring systems. Sulphate-reducing 
      bacteria (SRB), for example, Desulfovibrio sp., may be involved in the formation 
      of gold-bearing sulphide minerals in deep subsurface environments; over 
      geological timescales this may contribute to the formation of economic deposits. 
      Iron- and sulphur-oxidizing bacteria (for example, Acidothiobacillus 
      ferrooxidans, A. thiooxidans) are known to breakdown gold-hosting sulphide 
      minerals in zones of primary mineralization, and release associated gold in the 
      process. These and other bacteria (for example, actinobacteria) produce 
      thiosulphate, which is known to oxidize gold and form stable, transportable 
      complexes. Other microbial processes, for example, excretion of amino acids and 
      cyanide, may control gold solubilization in auriferous top- and rhizosphere 
      soils. A number of bacteria and archaea are capable of actively catalysing the 
      precipitation of toxic gold(I/III) complexes. Reductive precipitation of these 
      complexes may improve survival rates of bacterial populations that are capable of 
      (1) detoxifying the immediate cell environment by detecting, excreting and 
      reducing gold complexes, possibly using P-type ATPase efflux pumps as well as 
      membrane vesicles (for example, Salmonella enterica, Cupriavidus (Ralstonia) 
      metallidurans, Plectonema boryanum); (2) gaining metabolic energy by utilizing 
      gold-complexing ligands (for example, thiosulphate by A. ferrooxidans) or (3) 
      using gold as metal centre in enzymes (Micrococcus luteus). C. metallidurans 
      containing biofilms were detected on gold grains from two Australian sites, 
      indicating that gold bioaccumulation may lead to gold biomineralization by 
      forming secondary 'bacterioform' gold. Formation of secondary octahedral gold 
      crystals from gold(III) chloride solution, was promoted by a cyanobacterium (P. 
      boryanum) via an amorphous gold(I) sulphide intermediate. 'Bacterioform' gold and 
      secondary gold crystals are common in quartz pebble conglomerates (QPC), where 
      they are often associated with bituminous organic matter possibly derived from 
      cyanobacteria. This may suggest that cyanobacteria have played a role in the 
      formation of the Witwatersrand QPC, the world's largest gold deposit.
FAU - Reith, Frank
AU  - Reith F
AD  - School of Earth and Environmental Sciences, The University of Adelaide, CSIRO 
      Land and Water, Waite Laboratories, Urrbrae, South Australia, Australia. 
      Frank.Reith@csiro.au
FAU - Lengke, Maggy F
AU  - Lengke MF
FAU - Falconer, Donna
AU  - Falconer D
FAU - Craw, David
AU  - Craw D
FAU - Southam, Gordon
AU  - Southam G
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, Non-P.H.S.
PT  - Review
DEP - 20070920
PL  - England
TA  - ISME J
JT  - The ISME journal
JID - 101301086
RN  - 0 (Gold Compounds)
RN  - 7440-57-5 (Gold)
SB  - IM
MH  - Archaea/*metabolism/ultrastructure
MH  - Bacteria/*metabolism/ultrastructure
MH  - Gold/*metabolism
MH  - Gold Compounds/metabolism
MH  - Microscopy, Electron, Transmission
MH  - Models, Biological
RF  - 185
EDAT- 2007/11/29 09:00
MHDA- 2008/01/15 09:00
CRDT- 2007/11/29 09:00
PHST- 2007/11/29 09:00 [pubmed]
PHST- 2008/01/15 09:00 [medline]
PHST- 2007/11/29 09:00 [entrez]
AID - ismej200775 [pii]
AID - 10.1038/ismej.2007.75 [doi]
PST - ppublish
SO  - ISME J. 2007 Nov;1(7):567-84. doi: 10.1038/ismej.2007.75. Epub 2007 Sep 20.