Bacteria living off air in volcanic environment: research

Bacteria in nutrient-starved environments are literally able to live on thin air, according to new research by New Zealand scientists out Tuesday.

It was well-established that the majority of bacteria in soil ecosystems lived in dormant states due to nutrient deprivation, but the metabolic strategies that enabled their survival were previously unknown, said University of Otago scientists.

The researchers studied a strain of acidobacteria named Pyrinomonas methylaliphatogenes that lived in the inhospitable environment of heated and acidic geothermal soils in the Taupo Volcanic Zone, of the central North Island.

After in-depth studies of the genetic and biochemical capabilities of the organism, they found that when its preferred carbohydrate nutrient sources were exhausted, it was able to scavenge trace amounts of the fuel hydrogen from the air.

To survive, the organism simply required atmospheric hydrogen and oxygen, it was "living on thin air," study co-author Prof. Greg Cook said in a statement.

This was the first time that acidobacteria, the second most dominant bacteria in global soils, had been found to be able to consume hydrogen gas as an energy source.

"Even though there are only low concentrations of the gas in the air, it still provides them with a constant and unlimited resource for survival," he said.

The scavenging of trace gases, such as hydrogen, was likely to provide the energy to sustain a significant proportion of the bacterial communities in soils. Endi