BIOLOGY: MICROBES FOUND IN VOLCANIC ENVIRONMENTS COULD HELP REVEAL MORE ABOUT LIFE ON OTHER PLANETS

Researchers studying bacteria in Hawaii's lava caves have discovered intricate communities working together in hostile surroundings

- DR REBECCA PRESCOTT & DR STUART DONACHIE

Deep within the lava caves of Hawaii, microbial life thrives. In fact, a recent study has found that the life teeming within the caves is made up almost entirely of unknown species. More surprisingly, the researchers found that the microbial life was structured into complex networks of species that relied on each other. Within these networks were 'hub species', with so many links to other species that if they were removed, it could cause ecological collapse.

HOW DID YOU SEARCH FOR LIFE IN THESE LAVA CAVES?

Dr Rebecca Prescott: We had 70 samples of microbial mats [layers of microbes that live on surfaces] that we looked at from a variety of volcanic environments of different ages. The environments included lava tubes, geothermal caves and steam vents.

In order to identify the microbes, we looked at a gene called the '16S rRNA gene'. It's like a little tag that helps us with identification. We also looked at what microbes were 'hanging out' together, to try to better understand the structure of these communities.

TELL US MORE ABOUT THIS TECHNIQUE.

Dr Stuart Donachie: Prior to 1986, microbiologists could only identify microbes that they'd cultured in the lab. Everything we knew about microbial diversity - meaning how many species there are - was based only on what we could grow in Petri dishes. That gave us a rather narrow view, but it was the best we could do at that time.

In 1986, there was a method developed that involved sequencing [the 16S rRNA gene]. This method is based on extracting as much DNA as possible from the environmental sample, and then making copies of this particular gene. Once this method was applied in the environment, we detected bacteria that had never been seen before.