Microbes, Hawaiian Lava Tubes, and Life on Mars
Volcanic Developments, Pink Rocks & New Species
Lava tubes, natural channels formed by flowing volcanic lava, are of special interest in the search for life on other planets. They occur on other planets besides Earth, and their basaltic walls provide protection from radiation and harsh conditions that otherwise make surviving and thriving anywhere other than Earth a challenge - even for microbes.
We worked alongside collaborators at Georgetown University and the National Aeronautics and Space Administration to study microbes living in lava tubes beneath Mauna Loa, Earth’s largest active volcano.
We found a surprisingly high degree of niche partitioning over small spatial scales - meaning that competing species in lava tubes tend to partition resources or space in their niche to exist cooperatively. Based on recent bioinformatic advances in metagenomics, we assembled dozens of high-quality genomes (including those from several novel species!).
Our work was the first to combine 16S SSU rRNA sequencing and whole genome shotgun sequencing to map the microbial diversity and functional potential within a Hawaiian lava tube. Samples taken just centimeters apart revealed significant differences in community make-up, with implications for how to assay a region of interest on Mars.
In addition, the unique metabolism of a new genus discovered here provides a glimpse into the microbial communities in volcanic habitats and how they may evolve with limited nutrient availability in these extraordinary, martian-esque settings. Siliceabacter maunaloa was identified presumably for the first time in pink, gypsum-rich mineral deposits within lava tubes with direct sun exposure. Metabolic inference analysis suggests the microbe itself may contribute to the pinkish colour of the mineral deposit!
Read more here: https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2022JE007283