Surveys, simulation and single-cell assays relate function and phylogeny in a lake ecosystem

Area of Science:

• Microbial Ecology
• Biogeochemistry
• Environmental Microbiology

Background:

• Understanding microbial community structure and diversity drivers is crucial.
• Geochemical gradients in stratified environments may reveal functional microbial groups.
• Phylogenetic diversity and spatial correlation offer insights into microbial roles.

Purpose of the Study:

• To identify spatially correlated microbial groups in a chemically stratified lake.
• To investigate the relationship between microbial distributions and geochemical processes.
• To explore the functional roles of these microbial groups using genetic assays.

Main Methods:

• 16S ribosomal RNA gene sequencing to assess microbial community composition.
• Biogeochemical modeling to predict metabolic process distributions.
• Single-cell genetic assays to determine the presence of specific functional genes.

Main Results:

• Identified phylogenetically diverse microbial groups with spatial distributions correlating to predicted biogeochemical functions.
• Observed that groups linked to sulfate reduction had limited organisms with the necessary genes for this process.
• Highlighted a discrepancy between predicted function and genetic potential within identified microbial groups.

Conclusions:

• Spatially correlated microbial groups in stratified lakes may not always possess the direct genetic machinery for predicted functions.
• These groups might represent cooperative microbial consortia of diverse species.
• Cooperation among metabolically different microbes could drive key geochemical processes.