The effect of silver nanoparticles on seasonal change in arctic tundra bacterial and fungal assemblages.

The impact of silver nanoparticles (NPs) and microparticles (MPs) on bacterial and fungal assemblages was studied in soils collected from a low arctic site. Two different concentrations (0.066% and 6.

Freeze-thaw tolerance and clues to the winter survival of a soil community.

Although efforts have been made to sample microorganisms from polar regions and to investigate a few of the properties that facilitate survival at freezing or subzero temperatures, soil communities that overwinter in areas exposed to alternate freezing and thawing caused by Foehn or Chinook winds have been largely overlooked. We designed and constructed a cryocycler to automatically subject soil cultures to alternating freeze-thaw cycles. After 48 freeze-thaw cycles, control Escherichia coli and Pseudomonas chlororaphis isolates were no longer viable.