Structure and Assembly Mechanism of Archaeal Communities in Deep Soil Contaminated by Chlorinated Hydrocarbons

Chlorinated hydrocarbons are typical organic pollutants in contaminated sites, and microbial remediation technology has attracted more and more attention. To study the structural characteristics and assembly mechanism of the archaeal community in chlorinated hydrocarbon-contaminated soil, unsaturated-zone soil within 2~10 m was collected. Based on high-throughput sequencing technology, the archaeal community was analyzed, and the main drivers, environmental influencing factors, and assembly mechanisms were revealed. The results showed that chlorinated hydrocarbon pollution altered archaeal community structure. The archaeal community composition was significantly correlated with trichloroethylene ( r = 0.49, p = 0.001), chloroform ( r = 0.60, p = 0.001), pH ( r = 0.27, p = 0.036), sulfate ( r = 0.21, p = 0.032), and total carbon ( r = 0.23, p = 0.041). Under pollution stress, the relative abundance of Thermoplasmatota increased to 25.61%. Deterministic processes increased in the heavily polluted soil, resulting in reduced species richness, while positive collaboration among surviving species increased to 100%. These results provide new insights into the organization of archaeal communities in chlorinated hydrocarbon-contaminated sites and provide a basis for remediation activities.