Human health could suffer as rare Antarctic bacteria faces extinction

Rare bacteria could disappear from Antarctica before its known how they could benefit human kind.

It's been clear for a decade that algae and bacteria are taking advantage of melting snow and colonising new regions of Antarctica in a process known as "greening". But what’s been missed until now is that tiny microorganisms elsewhere are disappearing as the continent warms — some even face extinction.

Because scientists have been unable to effectively culture these rare gas-eating chemosynthetic bacteria little is known about the potential role they could play in new medical or technological developments, meaning human health and wellbeing could be the big loser if they're wiped out.

“We actually don’t know what they could do in terms of biotechnology. They could possess novel antibiotics,” University of NSW's Professor Belinda Ferrari told Yahoo News Australia. "In some of our soil samples there were at least 115 species of Eremiobacterota, so there could be a lot of diversity in what they can do."

Left - greening Antarctica. Right - A chemist in Australia.
Bacteria that's disappearing as Antarctica greens could be wiped out before its even been studied for important uses such as antibiotics. Source: Getty (File)

Even more concerning is the loss of these tiny bacteria could change the structure and appearance of Antarctic communities where they thrive. In the event of their demise, they would likely be replaced by bacterial weeds which favour milder, moister conditions associated with climate change.

Related: Seven dire reasons it might be time to leave Australia – from floods to fungus

Ferrari and her team at UNSW Sydney’s School of Biotech and Biomolecular Science began their research by examining soil samples taken almost 20 years ago from Eastern Antarctica where two species of chemosynthetic bacteria were abundant. They used modelling to predict how changes to the ecosystem could affect these strange microbes which survive by eating gases in the air.

When moisture changed in the environment Professor Belinda Ferrari’s team noted a “significant increase” in the amount of algae and bacteria that create greening through photosynthesis and a “significant decrease” in chemosynthetic bacteria.

“These organisms oxidise gas in the atmosphere to get enough energy to grow. In these environments we think they’ve been selected because its frozen and dark for the majority of the year — the gas provides a reliable source of energy,” Ferrari said.

Even more worryingly, a shift in microbe population could have a knock-on effect on the ecosystem where they grow, as they are likely removing the gases they consume from the atmosphere — hydrogen, carbon monoxide and carbon dioxide. It could even increase global heating at the sites where they once thrived.

More monitoring of Antarctic bacterial sites urgently needed

To see if their modelling was correct, the scientists compared their 2005 samples to others taken in 2019, they found a “big decrease” in chemosynthetic bacteria which was in line with their prediction. Levels dropped from around 10 per cent to 5 per cent.

But how bad things have got since the last samples were taken is unknown.

“We need to establish long term monitoring of these areas to see how significant the problem is. Because we don’t really know what’s happened over the last five years,” Ferrari said.

The University of NSW findings have been published in the journal Conservation Biology.

Love Australia's weird and wonderful environment? Get our new newsletter showcasing the week’s best stories.