## 3 Results and Discussion
### Impact of Amendments on the Composition of Soil Bacterial Communities  
Utilizing high-throughput sequencing methodologies, we analyzed the microbial community composition within soils subjected to diverse treatments. We derived results by employing a clustering threshold of 97% and normalizing to the minimum sample sequence count. The Venn diagram visually encapsulates the overlapping and distinct Operational Taxonomic Units (OTU) at the 97% similarity level across varied treatment modalities (Figure 5A). Common OTU shared among the control group (CK), the vermicompost treatment ensemble (L1), the steel slag treatment cohort (L2), and the confluence of vermicompost and steel slag treatment group (L3) were quantified at 65, with unique  
Figure 4: The biomass (**A**) and concentration of Cu (**B**) in _L. peremne_ under different treatments. Note: the bars sharing the different letters suggest significant differences (\(p<0.05\)).  
OTU numbering 65, 42, 13, and 41, respectively. Relative to the control group, the addition of vermicompost and steel slag engendered a diminution in unique OTU within each treatment milieu, signifying an amelioration in the distinct bacterial taxa prevalent in acidic soil stemming from copper sulfide. Conversely, in comparison to the control group, all alternative treatment assemblages exhibited an augmentation in the aggregate number of bacterial OTU. Particularly noteworthy enhancements were discerned in the vermicompost treatment group (L1) and the combined vermicompost and steel slag treatment group (L3), showcasing an elevation of 126.04% and 119.53%, respectively.  
The taxonomic composition at the phylum level within distinct treatment cohorts exhibits congruity in predominant species but divergence in their relative abundances (Figure 5B). Broadly construed, the prevailing phyla in the bacterial consortium are _Proteobacteria_ (27.48-60.94%), followed by _Actinobacteria_ (8.78-16.54%) and _Chloroflexi_ (5.03-17.75%), collectively constituting over 60% of the bacterial assemblage. Antecedent investigations posit that Proteobacteria and _Chloroflexi_ gradually ascend to the status of dominant species in soils contaminated with heavy metals, demonstrating formidable resilience to exigent environments [40, 41]. In relation to the control group (CK), the augmentation of vermicompost and steel slag engenders an amplification in the prevalence of Proteobacteria, _Bacteroidota_, and Firmicutes while concurrently instigating a decrement in _Actinobacteria_, WPS-2, and _Acidobacteriota_. Proteobacteria, characterized by heightened tolerance to pollutants, proficiently harness elevated concentrations of heavy metals and other deleterious substances as founts of energy and sustenance, thereby unveiling promising prospects for plant remediation and environmental safeguarding [42]. Furthermore, _Acidobacteriota_ and _WPS-2_, ubiquitously distributed in desolate and exposed soil domains, undergo a marked attenuation in abundance within treatment groups subjected to amendments. This phenomenon is ostensibly attributed to the escalation in soil pH induced by the application of steel slag and vermicompost, effectually immobilizing Cu\({}^{2+}\)[43, 44, 45].