Secrets of Antarctic microbes

The most extreme places in Antarctica give rise to the toughest and weirdest types of life. From creatures living a very different chemical life to ours at underwater methane seeps to the secret tools bacteria use to keep their DNA safe from the harsh conditions of the dry valleys.

Antarctica is a continent of extremes. The coldest. The driest. The windiest. It pushes life to the very limits. Living things down there have evolved some weird and interesting adaptations, which researchers are still discovering.

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Microbial mats and methane

Descending through the ice on a dive in Antarctica, Dr. Sarah Seabrook was struck by how alien it looked, like she could have been diving on Europa, one of Jupiter's icy moons. The dark volcanic sediment at the underwater base of Mt Erebus brought a white fluffy mat into sharp focus, like snow scattered on the seafloor.

It was 2016 and this fluffy mat was the reason that Seabrook was there, diving in the area as part of her PhD research. Under the supervision of Dr. Andrew Thurber of Oregan State University, Seabrook was able to confirm exactly what it was - a mat of methane-loving microbes attracted to the area by a methane seep.

Methane is a gas - the main component of natural gas and a potent (albeit relatively short-lived) greenhouse gas. It can be produced by microbes on land that live in landfills, the soil, or in the stomachs of ruminants, like cows and sheep. But it is also produced when old organic matter is broken down by high temperatures and pressures in rock deep under the ground.

Methane seeps are what happens when this trapped methane reaches the seafloor surface and leaks out. These seeps support amazing and weird deep-sea habitats, the foundation of which are microbes that can make energy from methane, in the absence of light. Methane seeps are found at tectonic plate margins around the world, but their presence in Antarctica is poorly understood.

This is what Seabrook wants to investigate.

She has gathered further evidence of seeps and gas plumes in other areas of the Ross Sea that hint to a wider network. With another research trip to Antarctica planned in 2023, she's hoping to figure out the puzzle of methane seeps in Antarctica, and the weird living things that they support.

Dr. Sarah Seabrook's work at NIWA is supported by the Antarctic Science Platform and the New Zealand Antarctic Resilience initiative. Previous research discussed in this episode was supported by the National Science Foundation and Oregon State University in the United States.

DNA repair tools of extreme bacteria…

Go to this episode on rnz.co.nz for more details