Viral Induced Microbial Mortality in Arctic Hypersaline Spring Sediments

Area of Science:

• Microbiology
• Marine Biology
• Environmental Science

Background:

• Viruses significantly influence microbial mortality globally.
• The role of viruses in low-energy marine environments remains understudied.
• Understanding viral impacts is crucial for comprehending microbial dynamics in extreme habitats.

Purpose of the Study:

• To investigate viral impacts on microbial mortality in cold, hypersaline springs.
• To determine the relationship between microbial growth, viral activity, and resource limitation.
• To assess the prevalence and impact of inducible proviruses in these systems.

Main Methods:

• Conducted in situ time-series incubations in Arctic spring sediments.
• Measured microbial growth and viral decay rates.
• Utilized chemical induction to assess provirus release and amended microcosms with organic carbon.

Main Results:

• Microbial and viral populations were in dynamic equilibrium with low growth and decay rates.
• A significant portion of viruses were refractory to decay.
• Organic carbon (lactate, acetate) limited microbial growth.
• Proviruses were inducible in a substantial fraction of the microbial community.
• Viruses attenuated microbial growth by 8-29%.

Conclusions:

• Viruses in low-energy systems exhibit low production and activity.
• Non-lethal viral replication strategies are prevalent.
• Viruses are a minor driver of mortality in cold, low-biomass environments compared to high-energy systems.