Bacterial Communities in Antarctic Lakes Show Higher Variability Across Space Than Over Time

Strategic Insights -

Research findings have shed new light on the dynamics of bacterial communities in Antarctic lakes, revealing higher variability across space than over time. The study, conducted by Guillaume Schwob and colleagues, focused on 11 lakes on the Fildes Peninsula in Maritime Antarctica, sampled during austral summers from 2017 to 2023. The researchers used 16S rRNA gene sequencing to investigate the spatial and inter-annual variation of bacterial community structure and their underlying assembly processes.

Key Takeaways:

  • The bacterial communities in Antarctic lakes primarily clustered by habitat, with higher diversity in sediment compared to water.
  • Spatial turnover of communities dominated over inter-annual variation in both habitats.
  • The temporal core microbiome showed greater stability than the spatial core.
  • Community assembly processes differed between habitats, with a stronger contribution of dispersal limitation in sediment, versus ecological drift in water.
  • Spatial and temporal variations in sediment were driven by globally similar assembly processes.
  • In contrast, in water communities, different assembly processes explained the spatial and temporal variation.
  • The study emphasizes the need to consider both spatial and temporal scales and various habitat types when predicting future bacterial dynamics in Antarctic lakes in a changing environment.
  • The study also highlights the importance of understanding the inherent baseline microbial dynamics in Antarctic lakes to predict their responses to environmental changes.

Statistics:

  • 11 lakes on the Fildes Peninsula in Maritime Antarctica were sampled for the study.
  • The study spanned 6 years, from 2017 to 2023.
  • 16S rRNA gene sequencing was used to investigate the bacterial community structure.
  • The communities exhibited higher diversity in sediment (characterized by Actinobacteria and Firmicutes) compared to water (characterized by Proteobacteria, Bacteroidetes, and Fusobacteria).
  • Spatial turnover of communities dominated over inter-annual variation in both habitats.
  • The temporal core microbiome showed greater stability than the spatial core.

Sources:

  • Guillaume Schwob, et al. "Higher variability of bacterial communities across space than over time in Antarctic lakes, and contrasting assembly processes." Applied and Environmental Microbiology, 2025.
  • Published by: Amer Soc Microbiology, 1752 N St NW, Washington, DC 20036-2904, USA.
  • Contact: Additional information may be obtained from Guillaume Schwob, Millennium Institute Biodiversity of Antarctic and Subantarctic Ecosystems (BASE), Santiago, Chile.
  • DOI: Not available.