Environmental Microbial Metagenomics Projects

Australia is one of the few megadiverse countries and possess unique habitats for microbial colonisation. It includes hypersaline habitats, subsurface thermal (non volcanic) habitats and unique animals and insects whose guts containg unique microbes. Most of the Australian microbial diversity remains unknown. The project will seek to redress this. Of all the known habitats, the most interesting is the deep subsurface thermal aquifer know as the Great Artesian Basin of Australia. It is the by far the largest known aquifer in the world and spans one-third of the Australian continent underground. The GAB underlies the most arid regions of Australia, and the water is brought to the surface by free-flowing bore wells. Some 5,000 bore wells have been drilled into the GAB basin to tap the water which is than used by the outback community mainly as a drinking water for farm animals. The temperature at the bore well source ranges from the ambient to boiling and the chemistry fluctates widely in it's inorganic and organic composition depending on the depth and the origin of the waters. The basin recharge is along the Eastern margins of Australia along the Great Dividing mountain ranges and the natural discharge occurs as hypersaline mound springs in central Australia. The underground water flow rate from the recharge to the discharge sites is 1 meter per year

Over the past 18 years We have investigated the microbiology and the microbial diversity of at least 50 bores and found vastly different thriving microbial communities in the deep biosphere and also colonising the bore well drains on the surface. I have chosen 4 bore wells to illustrate the physicochemical features of the bores and massive visible colonisation that can occur to illustrate the reasons why scientific studies using metagenomes will be interesting. In addition, there is biotechnological commercial potentional for these metagenomic libraries.

Bore 1 contains and releases only trace amounts of natural gas as it overlies coal seams.

Bore 2 contains extensive natural gas and is emitted with the water. It also overlies an extensive large coal seam.

Bore 3 contains large concentrations of reduced iron (anaerobic environment) which is oxidised to precipitated rust within 30 secs of exposure to air (yellow color) during sample collection. The bore temperatuer is 58 degrees centigrade.

The temperature of this 4th bore is 89 degrees centigrade at its source. The water forms a temperature gradient as it cools in the runoff channels. The temperature ranges from 88 degrees centigrade below the bore source to ambient. Visible microbial mats are obsereved colonisisng spatially rather than continuously. This feature is unique and has not been observed in volcanic hot springs.

Suggestions and Comments to: Professor Bharat Patel <B.Patel@griffith.edu.au>
[Created: 05 Sept 1995]
[Modified: 12 April 2007]