In the heart of the Amazon, the first rays of sun reveal a mist clinging to the treetops. This mist, although it seems like simple vapor, actually harbors viable microorganisms traveling in its tiny droplets. A recent study conducted at the Amazon Tall Tower Observatory (ATTO) has discovered up to 98,000 microbial cells per milliliter of fog water.
The ATTO, located 150 kilometers from Manaus, is a beacon of scientific research. An international team managed to isolate eight species of bacteria and seven of fungi from the mist, publishing their findings in the journal Communications Earth & Environment on February 3, 2026.
The research highlights how the mist acts as a transportation medium for these microorganisms, allowing their survival and mobility. Using flow cytometry, active microbial cells were identified, although concentrations varied significantly between samples, from low figures to nearly 98,000 cells per milliliter.
Within the mist, bacteria such as Serratia marcescens and fungi like Aspergillus niger were found, the latter present in 43% of the samples. These organisms are related to soil and plants, suggesting a local origin.
The study used a Caltech Active Strand Cloud Collector (CASCC2) to collect samples at 43 meters high on the 325-meter ATTO tower. Samples were collected during 2022 and 2023, facing the logistical challenges of such a remote environment.
Microbial cells
A key aspect of the study is how these microbes could be influencing the ecology of the forest. The mist, as it forms and rises, transports microorganisms that could facilitate the colonization of new areas, according to chemist Ricardo Godoi. However, the authors caution that more evidence is needed to fully understand their role.
The Amazon, a huge “water pump“, generates up to 50% of the regional rainfall through evapotranspiration. The mist, therefore, not only transports microbes, but could also influence the dynamics of rain. However, climate change and deforestation threaten these delicate conditions, reducing humidity and affecting the formation of mists.
The study suggests that, to better understand this phenomenon, metagenomic techniques should be employed to analyze the DNA of the microorganisms in their entirety. This could reveal the true diversity of microbes traveling with the mist.
In summary, protecting the Amazon rainforest also involves safeguarding its microclimate, crucial for the dispersion and survival of its microorganisms. This study, published in Communications Earth & Environment, marks the beginning of our understanding of the role of mist in the Amazon ecosystem.
