Scientists find unique organisms in geothermal areas

State scientists who spent three years cataloguing micro-organisms living in geothermal systems around the Taupo volcanic zone say some of them are not found anywhere else in the world.

"New Zealand geothermal systems house an extraordinary population of unique and possibly globally-rare micro-organisms," said GNS Science researcher Matthew Stott.

"We're still not sure whether this diversity relates to the uniqueness of New Zealand geothermal systems, or whether it's because of the relative immaturity of the global understanding of microbial ecology science.

Around the North Island's volcanoes and geothermal areas, GNS has collected over 1000 different species of extremophile bacteria that live in extremes of temperature, acidity, alkalinity, pressure, and salinity -- often without sunlight or oxygen.

One of them was a methane-consuming organism that lives at Tikitere geothermal field -- also known as Hell's Gate -- near Rotorua and thrives in extremely acidic conditions.

That bacterium could potentially be used to reduce methane gas emissions to the atmosphere from landfills or geothermal power stations - they are "methanotrophs" which use methane as their only source of energy.

Other methanotrophs are known to live in soils, but the newly-discovered species are able to live in hotter and much more acidic conditions.

GNS researchers worked with University of Hawaii scientists to sequence the genome of the bacterium, and found that its genetic make-up was different to all known methanotrophic organisms.

The land owner and operator of Hell's Gate, Tikitere Trust, has a benefit-sharing deal with GNS Science for any financial gains from the discovery.

GNS Science yesterday told Environment Waikato environment committee meeting in Hamilton DNA sequencing work had revealed an "extraordinary diversity" of bacterial species in the geothermal systems, the function and role of many of which were unknown. "Up until now the microbial diversity in geothermal systems in the Taupo Volcanic Zone has not been systematically catalogued," Dr Stott said.

Micro-organisms make up 50 per cent of the world's biomass and are crucial to the healthy functioning of the planet, but Dr Stott said scientists know only 5-10 percent of those microbial species.

Two particular highlights of the study were the discovery of a new microbial metabolism in a species isolated from a geothermal soil, and that scientists had managed to grow the first representative of a new phylum (taxonomic rank).

Some of the species found in the Taupo geothermal systems showed potential for use in new technologies. Many geothermal micro-organisms are being studied for medicinal and commercial applications, or are already being used for industrial processes, Dr Stott said. A DNA identification technique used in forensic and other applications relies on a thermophilic (heat-loving) micro-organism isolated from Yellowstone National Park, in the USA, while Waikato University scientists have exploited a bacteria from a similar environment 4000m up Antarctica's Mt Erebus to produce a heat-stable enzyme in DNA tests.

These are not the first organisms used like this -- an early case of bio-piracy three decades ago involved a Japanese researcher who took an organism from a geothermal pool in New Zealand to create medicines which could cope with a greater range of temperatures without refrigeration.

The regional council's environment committee chair Jane Hennebry said knowing what micro-organisms were present in geothermal systems would help the council set priorities to protect biodiversity.

"To do this for geothermal ecosystems we need to know about the range of micro-organisms they contain," she said. "We also need to know whether they are unique to New Zealand and if they are under threat, and what extra measures we need to take to protect them."

The GNS Science study was principally funded by a $180,000 grant from the Wairakei Environmental Mitigation Charitable Trust.

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