Airborne bacterial community diversity, source and function along the Antarctic Coast

Area of Science:

• Microbiology
• Atmospheric Science
• Marine Ecology

Background:

• Antarctica's isolated ecosystem offers unique insights into airborne microbial spread and climate change prediction.
• Limited knowledge exists regarding the diversity and sources of coastal Antarctic marine atmospheric microorganisms.

Purpose of the Study:

• To investigate the diversity, sources, and functional potential of airborne bacterial communities along the Antarctic coast.
• To understand the influence of environmental factors on these microbial communities.

Main Methods:

• 16S rRNA gene amplicon sequencing of 25 bioaerosol samples.
• Analysis of bacteriome composition using canonical correspondence analysis.
• Prediction of functional profiles using Tax4fun2.

Main Results:

• Bacterial communities were dominated by Proteobacteria (91.3%), notably Sphingomonas.
• Observed low alpha-diversity but high spatiotemporal variability.
• Identified potential immigration pathways including terrestrial, marine, and polar bacteria via long-range transport and sea-air exchange.
• Wind speed, temperature, and organic carbon significantly affected bacterial communities (P < 0.05).
• No significant differences in richness or diversity were found across different weather conditions (P > 0.05).
• Predicted functional genes support fatty acid, amino acid, nucleotide, and carbohydrate metabolism.

Conclusions:

• Airborne bacteria in Antarctica are primarily Proteobacteria, with diverse origins and significant environmental influences.
• These microbes play a role in ocean surface microlayer formation and survival.
• Further research is needed to fully understand microbial roles in polar atmospheric and marine environments.