Geomicrobiology
Introduction
Welcome to the world of GEOMICROBIOLOGY! In a nutshell, geomicrobiology includes microbes that "eat rocks". A more precise definition is "a subset of the scientific discipline microbiology. The field of geomicrobiology concerns the role of microbe and microbial processes in geological and geochemical processes. The field is especially important when dealing with microorganisms in aquifers and public drinking water supplies." (wikipedia)
This page will discuss a broad introduction to what geomicrobiological processes are all about, key microorganisms found in geomicrobiology, examples of such microbes, and current research in this field.
Enjoy!
Process - key points
Describe the process, using as many sections/subsections as you require. Look at the list of other topics. Which involve processes similar to yours? Create links where relevant.
Geobiology habitats
place
soil---aggregate pore
water--deep sea
Hydrothermo vent
condition
Temperature extreme---polar
PH-Low or High PH env.
Atmosphere-
Microbial Energetics
Geobiology method
We need to measure redox potential, PH, temperature and available electron donor and acceptor. Microbe foam a consortium so we need pure isolate method. Phase contrast, DIC, Epiflorsentce FISH MPN
Key Microorganisms within Geomicrobiology
Geomicrobiology included organisms that are concidered extremophiles. Extremophiles are microorganisms that live in areas considered too hostile for most. An example of an extremophile is anerobic sulfate reducing bacteria, which are know to live in hyper-saline lagoons in Brazil and Australia. It is believed these bacteria may be responsible for the formation of dolmite
Examples of Microorganisms
An example of extemophile organism is: anaerobic sulfate-reducing bacteria
Sulfate-reducing bacteria (SRB) comprise of several groups of bacteria that use sulfate as an oxidizing agent, reducing it to sulfide. Most sulfate-reducing bacteria can also use other oxidized sulfur compounds such as sulfite and thiosulfate, or elemental sulfur. This type of metabolism is called dissimilatory, since sulfur is not incorporated - assimilated - into any organic compounds. Sulfate-reducing bacteria have been considered as a possible way to deal with acid mine waters that are produced by other bacteria.
Another interested description of SRB is found at http://www.glossary.oilfield.slb.com/Display.cfm?Term=sulfate-reducing%20bacteria.
Acidithiobacillus is a genus of proteobacteria. The members of this genus used to belong to Thiobacillus, before they were reclassified in the year 2000. Members of this genus can be fined in pyrite deposits, metabolizing iron and sulfur and producing sulfuric acid. Example: Acidithiobacillus thiooxidans consumes sulfur and produces sulfuric acid. This bacterium in conjunction with others of the same genus is currently used in a mining technique called bioleaching whereby metals are extracted from their ores through oxidation. The bacteria are used as catalysts.
Hydrogenophilaceae also belongs to the Proteobacteria, and it is believed to be made of two genera. They are thermophilic bacterium growing in temperatures close to 50 °C. They obtain their energy from hydrogen oxidation. Example: Thiobacillus genus; includes only species from beta proteobacteria. This bacterium is used as a pest control in potato fields to control scabs.
The Epsilon-proteobacteria have recently been recognized as globally ubiquitous in marine and terrestrial ecosystems. They play a major role in biogeochemical and geological processes and have been isolated from sulfur rich terrestrial and marine environments, some of which are considered extreme habitats. Most representatives are only known through the 16S rRNA gene sequence despite current effort to develop culture techniques.
This is a very good paper that talks about the current debated with Epsilonproteobacteria from which certain members also are considered geomicrobes
Campbell, B.J., Engel, A.S., Porter, M.L., and Takai, K. (2006) The versatile Epsilonproteobacteria: Key players in sulphidic habitats. Nature Reviews Microbiology. 4: 458-468.
Current Research and Links
There is a very intresting site hosted by the Geomicrobiology & Environmental Microbiology Studies at Louisiana State University http://www.geol.lsu.edu/aengel/index.htm This site is filled with current research photos and informative discussions concerning the topic.
References
Edited by student of Kate Scow
