How bacteria migrate: Saharan microbial community found in the Alpine snow

Climate change and over-use of the ground has provoked migrations that cannot be stopped, those of microorganisms. A multidisciplinary team of microbiologists, geologists, chemists and bioclimatologists from the Fondazione Edmund Mach of San Michele all’Adige, the Institute of biometeorology of the National Council for Research (Ibimet-Cnr), Ca' Foscari University and the universities of Florence and Innsbruck has studied the microbial load of one of the most intense movements of Saharan dust that reached the Alps in 2014, publishing the results in the prestigious journal Microbiome.

This great storm has deposited enormous quantities of Saharan dust on the Dolomite Alps that was sealed between layers of “clean” snow. This enabled a precise determination of microorganisms associated with the deposition.

In the clean rooms (laboratories with controlled contamination) of the Scientific Campus at Ca’ Foscari the geochemical analyses necessary for the study were carried out. Professor Carlo Barbante and the research grant holder Luisa Poto collaborated on this study.

In the snow samples collected from Marmolada and Latemar by the Ca’ Foscari team, the researchers found proof that the big dust storms can not only move fractions, but entire microbial communities (bacteria and fungi) from the Saharan area to Europe, that contain many organisms that are extremely resistant and able to survive in different environments.

The analysis of the genetic descriptions of frozen bacteria and fungi and the microbial community of the soil has allowed researchers to verify that some of these Saharan microbes even survive after the snow has melted, probably because they exist in such large quantities. The findings suggest that climate change and the increase in frequency of these events could significantly change the microbe community in our soil, transporting entire microbe communities far away.

Accepting the challenge recently launched by the United Nations for the implementation of monitoring and protecting the microbes’ long-range transportation during sand and dust storms, the creators have suggested fast and efficient methods for monitoring the risks associated with the fusion of snow and glaciers contaminated by the microbial populations that arrive from afar. This is one way to achieve effective early warning systems.

This study has been made possible by modern and sophisticated research tools: amongst them the meta-genomic and computerized biology of Fem. “Since the latest generation of sequencing techniques has given researchers the possibility to see microorganisms without cultivating them on a Petri dish, but instead identifying them directly from their DNA descriptions, it has been discovered that the bacteria and fungi are present in all environments, including air, cloud and wind” conclude the researchers.