Strong in combination: Polyphasic approach enhances arguments for cold-assigned cyanobacterial endemism

Area of Science:

• Ecology
• Microbiology
• Biogeography

Background:

• Cyanobacteria in biological soil crusts (BSCs) are vital in polar and alpine ecosystems, acting as ecological indicators and engineers.
• Understanding cyanobacterial distribution in cold biomes is crucial for assessing ecosystem health and climate change impacts.

Purpose of the Study:

• To characterize cyanobacteria in polar and alpine BSCs using a combination of molecular and cultivation techniques.
• To determine the living cyanobacterial proportion and compare it with previous meta-transcriptome data.
• To investigate geographic distribution patterns and community compositions of cyanobacteria in cold environments.

Main Methods:

• Combined denaturing gradient gel electrophoresis (DGGE), light microscopy, and culture-based 16S rRNA gene sequencing.
• Analysis of cyanobacterial communities from Arctic, Alpine, and Antarctic biological soil crusts.
• Phylogenetic assignment of isolates to identify cold biome clades.

Main Results:

• Distinct clustering of cyanobacterial communities was observed, with Arctic and Alpine populations showing a close relationship.
• Antarctic cyanobacterial communities differed significantly from Arctic and Alpine ones.
• Microscopic and sequencing data confirmed species richness and diversity trends, identifying a potentially new Arctic Oculatella clade.

Conclusions:

• The study highlights distinct biogeographic patterns of cyanobacteria in cold biomes.
• The integrated methodology effectively characterized cyanobacterial communities in BSCs.
• Findings contribute to the understanding of cyanobacterial diversity and distribution in polar and alpine regions.