Impact of storage and extraction methods on peat soil microbiomes

Area of Science:

• Environmental Microbiology
• Soil Science
• Molecular Ecology

Background:

• Peat soils are critical carbon reservoirs, with microbiomes influencing climate feedbacks.
• Microbial community structure recovery is sensitive to sample handling and processing.
• Understanding methodological impacts is vital for accurate peatland microbiome studies.

Purpose of the Study:

• To evaluate the effects of different storage conditions and nucleic acid extraction methods on peat soil microbial communities.
• To identify method-based biases in microbiome recovery from distinct peatland habitats.

Main Methods:

• Tested three in-field storage conditions (LifeGuard, flash-freezing, transport on ice) followed by -80 °C storage.
• Applied five distinct nucleic acid extraction protocols to peat soil samples from three Stordalen Mire habitats.
• Analyzed bacterial and archaeal community structure using amplicon sequencing.

Main Results:

• Initial storage method affected alpha diversity but not beta diversity.
• Nucleic acid extraction method significantly impacted both alpha and beta diversity.
• One extraction kit (PowerSoil Total RNA Isolation kit with DNA Elution Accessory kit) yielded distinct microbial taxa and community structures compared to others.

Conclusions:

• Methodological choices introduce significant biases in peat soil microbiome recovery.
• Habitat and sample depth remain dominant factors, but method effects are substantial.
• Standardized methodologies are essential for robust inter-study comparisons and ecological interpretations in peatland research.