Soil microbial community structure and functionality changes in response to long-term metal and radionuclide...

Area of Science:

• Environmental microbiology
• Soil science
• Ecotoxicology

Background:

• Soil microbial communities are vital for ecosystem health.
• Metals and radionuclides pose persistent threats to soil microbes.
• Limited understanding exists regarding long-term co-contamination effects.

Purpose of the Study:

• To investigate the impact of historical industrial discharges (phosphate and nuclear) on soil microbial communities.
• To analyze the effects of metal and radionuclide co-contamination gradients on microbial structure and function.
• To assess the relationship between chemical contamination and bacterial community dynamics.

Main Methods:

• Sampling eight locations along a river transect and one field location in the Grote Nete river basin.
• Chemical analysis to establish metal and radionuclide contamination gradients.
• Microbial profiling and cultivation-dependent experiments to assess community structure, biomass, and functional resilience.

Main Results:

• A clear gradient of metal and radionuclide contamination was identified, correlating with distinct microbial community clustering.
• Bacterial community structure was significantly related to chemical contamination parameters.
• While microbial biomass remained unchanged, communities from contaminated sites exhibited enhanced survival on singular metals compared to control sites.
• Nitrification, a crucial soil process, appeared to be negatively affected in contaminated locations.

Conclusions:

• Long-term co-contamination by metals and radionuclides profoundly impacts soil microbial community structure and function.
• Contaminated soil microbial communities display altered resilience and functional responses.
• This study provides fundamental insights into microbial dynamics in environments affected by co-occurring metal and radionuclide pollution.