Microbial communities in rare earth mining soil after in-situ leaching mining

Area of Science:

• Environmental microbiology
• Soil science
• Mining ecology

Background:

• In-situ leaching for rare earth elements (REEs) causes significant soil ecosystem damage.
• Limited understanding exists regarding the impact of mining on soil microbiota.

Purpose of the Study:

• To investigate the diversity and composition of prokaryotic and ammonia-oxidizing microorganisms in rare earth mining soils.
• To understand the influence of in-situ leaching on soil microbial communities and their functions.

Main Methods:

• Quantitative Polymerase Chain Reaction (qPCR) to quantify microbial abundance.
• Illumina high-throughput sequencing for microbial community analysis.
• Correlation and network analyses to identify key environmental factors and microbial interactions.

Main Results:

• In-situ leaching negatively impacted bacterial, archaeal, and ammonia-oxidizing archaea (AOA) abundances, correlating with ionic REEs.
• Bacterial community structure was predicted by total REEs and ammonium; archaeal community structure by organic matter.
• Thaumarchaeota dominated archaeal communities, with unclassified Thaumarchaeota and Crenarchaeota being predominant AOA groups.
• Ammonia-oxidizing bacteria (AOB) were not detected, indicating archaea are the primary drivers of ammonia oxidation.

Conclusions:

• Rare earth mining via in-situ leaching profoundly alters soil prokaryotic communities and ammonia-oxidizing microorganisms.
• Archaea, particularly AOA, play a dominant role in ammonia oxidation in these mining-affected soils.
• Positive microbial interactions may enhance soil microbial resilience in harsh mining environments.