Unlocking Microbial Secrets: New DNA Technique Reveals Life in Atacama Desert

A new technique helps researchers study microbial life in the Atacama Desert. This desert is the driest place on Earth and has extreme conditions. Scientists collected soil samples to explore the microbes that live there.

The challenge was to separate DNA from living organisms (iDNA) from DNA of dead organisms (eDNA). Traditional DNA extraction methods mix both types, making it hard to identify active microbes. The new method distinguishes between living and dead microbial DNA.

Researchers used this technique on soil samples taken from the coast to the foothills of the Andes. They discovered various active microbes in the most arid regions. Dirk Wagner, a geomicrobiologist leading the study, noted that understanding both eDNA and iDNA can shed light on microbial functions.

These microbes play a crucial role in preparing harsh environments for future life. This knowledge is not only applicable to deserts but also to new landscapes formed after events like earthquakes and landslides.

Wagner explained that traditional DNA extraction tools result in a mix of DNA types. Their new method involves gentle rinsing to filter intact living cells, leaving solely the eDNA in the sediment. Lab tests showed that after repeated rinsing, almost all DNA separated into living and dead categories.

In the Atacama samples, they found two types of bacteria, Actinobacteria and Proteobacteria, in both iDNA and eDNA groups. They also observed that communities with high activity showed similar amounts of iDNA and eDNA. In samples from shallow depths, they noted a prevalence of Chloroflexota bacteria among living cells.

In future studies, Wagner aims to conduct further analysis on the iDNA samples to learn more about active microbes. He plans to apply the same approach to other extreme environments. This research could provide deeper insights into essential microbial communities.

Reference: “Inside the Atacama Desert: uncovering the living microbiome of an extreme environment” by Dirk Wagner et al., 14 November 2024, Applied and Environmental Microbiology. DOI: 10.1128/aem.01443-24