Discovery of Viable Microbes in Amazonian Fog
The Amazon rainforest, often called the lungs of the Earth, harbors countless secrets about its resilience and biodiversity. A groundbreaking study funded by FAPESP has revealed that fog in the Amazon acts as a natural transporter for live microorganisms, potentially playing a key role in the forest's regeneration. Researchers from the Federal University of Paraná (UFPR) and an international team identified viable bacteria and fungi in fog droplets collected high above the forest floor, marking the first such observation in this ecosystem.
This discovery challenges previous understandings of microbial dispersal in tropical forests. Traditionally, wind and rain were thought to be primary vectors for spreading soil microbes to the canopy. However, fog provides a gentler, more protective medium, shielding these tiny life forms from harsh ultraviolet radiation and desiccation.
The Amazon Tall Tower Observatory: A Research Powerhouse
At the heart of this research is the Amazon Tall Tower Observatory (ATTO), a 325-meter structure in a pristine area near Manaus, Amazonas, Brazil. Operated by the National Institute for Amazonian Research (INPA) and Germany's Max Planck Society, ATTO offers unparalleled access to the rainforest atmosphere. Fog samples were gathered at 43 meters height during nighttime events between 2021 and 2023, capturing 13 distinct occurrences across wet and dry seasons.
Brazilian institutions like UFPR, University of São Paulo (USP), and Instituto Adolfo Lutz played pivotal roles. Led by chemist Ricardo H. M. Godoi from UFPR's Environmental Engineering Department, the team included 36 experts from seven countries, showcasing Brazil's growing influence in global environmental science.
Methodology: Capturing Invisible Passengers
Using the Caltech Active Strand Cloud Collector (CASCC2), researchers sucked in fog droplets without contamination from ground vehicles or rain. Samples were analyzed via flow cytometry, revealing cell concentrations from 35,000 to 98,000 per milliliter—comparable to cloud water elsewhere. Dyes like Rhodamine 123 and Hoechst 33342 confirmed metabolic activity and intact DNA.
Culturing on specialized media isolated eight bacterial species, including Serratia marcescens, Ralstonia pickettii, and Sphingomonas paucimobilis, plus seven fungal taxa like Aspergillus niger and Penicillium spp. Mass spectrometry (MALDI-TOF MS) provided precise identification. Vertical profiles from ATTO's Robotic Lift (RoLi) showed fog layers up to 150 meters, with reduced aerosols inside, highlighting microbes' role as condensation nuclei.
- Collections: Nighttime (3-7 AM), avoiding combustion engines.
- Analysis: Flow cytometry for viability; culturing for species ID.
- Seasons: Late wet (Apr-May 2022), late dry (Oct 2022), early wet (Jan 2023).
Key Findings: A Microbial Elevator
The study, published February 3, 2026, in Communications Earth & Environment (DOI: 10.1038/s43247-026-03233-4), found no significant seasonal variation in cell counts (p=0.49), but higher bacterial diversity in wet seasons. Negative zeta potentials (-12 to -27 mV) in droplets facilitate microbial incorporation via electrostatic forces.
These decomposers from soil—typically breaking down organic matter—can now colonize canopy areas via fog uplift. Fog's diurnal cycle (formation at night, rise with dawn winds) disperses them widely, explaining uniform microbial distribution in the forest.
Implications for Forest Regeneration and Biodiversity
Microbes like Serratia marcescens (opportunistic pathogen but soil decomposer) and Aspergillus niger (industrial enzyme producer) recycle nutrients, supporting plant growth. Fog dispersal could enhance forest recovery post-disturbance, as these microbes break down litter, releasing phosphorus and nitrogen.
Prior ATTO studies showed Saharan dust delivering iron and microbes; fog complements this aerial nutrient highway. For Brazil's higher education, this underscores UFPR and partners' contributions to ecology, with FAPESP funding enabling cutting-edge fieldwork.
Threats from Climate Change and Human Activity
However, rising temperatures, drier conditions from deforestation, and biomass burning may reduce fog frequency. FAPESP-linked research warns of cascading effects: less microbial transport could slow decomposition, nutrient cycling, and regeneration, exacerbating Amazon dieback.
Bruno Rosado from UERJ notes potential limitations—microbes may already abound—but calls for experiments testing deposition impacts. A related FAPESP study on microplastics and warming altering aquatic microbes highlights broader risks (Revista Pesquisa FAPESP).
Brazilian Universities Driving Amazon Research
UFPR's Ricardo Godoi, with alumni like Cybelli Barbosa and Bruna Sebben, leads. USP's Fábio Gonçalves supplied collectors; Instituto Adolfo Lutz handled cultures. INPA maintains ATTO, fostering collaborations.
This aligns with Brazil's research push: FAPESP's investments yield global papers, training postdocs and students in atmospheric microbiology. Opportunities abound in research positions at these institutions.
| Institution | Role |
|---|---|
| UFPR | Lead analysis, cytometry |
| USP | Meteorology, equipment |
| Instituto Adolfo Lutz | Culturing, ID |
| INPA/ATTO | Site access, data |
Future Directions and Broader Impacts
Next: Metagenomics for full DNA sequencing; Sirius synchrotron for particle chemistry. Long-term monitoring at ATTO will track fog-microbe-climate links.
For higher education, this inspires interdisciplinary programs in environmental engineering, microbiology. Brazil's /br/universities lead tropical research, with jobs in Brazilian academic positions.
Photo by masakazu sasaki on Unsplash
Related Studies and Global Context
Prior work: 2022 NPJ paper on giant bioaerosols; 2019 Maine/Namib fog study. Amazon's fog microbes join global patterns, but tropical specifics unique.
Implications extend to agriculture (nutrient cycling), public health (pathogen dispersal), climate modeling. FAPESP's role exemplifies state-university synergy.
- Evans et al. (2019): Fog microbes link ecosystems.
- Souza et al. (2021): Seasonal aerosol microbiome.
Conclusion: Fog as Unsung Hero of the Amazon
This FAPESP-backed study illuminates fog's role in microbial transport, vital for Amazon regeneration. As Brazil's universities like UFPR pioneer such research, protecting fog-forming conditions becomes urgent amid climate threats. Explore careers in this field via research jobs.
