Heavy metal(loid) (HM) contamination in soils from smelting activities poses significant environmental and public health risks, as well as disruptions in microbial community dynamics and HM resistance gene profiles. This study investigates the microbial diversity, resistome, and physicochemical properties of soils from the abandoned Avalos smelter in Chihuahua, Mexico. Through soil analyses, we identified elevated concentrations of certain HMs, which pose serious environmental and health hazards. The metagenomic analysis of the microbial community, composed of bacteria, archaea, and fungi, was dominated by genera such as Streptomyces, Bradyrhizobium, Halobaculum, Nitrosocosmicus, Fusarium, and Aspergillus in rhizospheric soil. Furthermore, a diverse array of metal resistance genes (MRGs) were detected, associated with copper, arsenic, iron, lead, cadmium, zinc, and other HMs. Additionally, metagenome-assembled genomes (MAGs) revealed the presence of functional genes linked to HM resistance, providing deeper insights into the ecological roles and metabolic capabilities of microbial taxa. These findings highlight the significant impact of smelting-derived contamination on microbial diversity and functional potential, offering valuable insights for the development of bioremediation strategies in HM-contaminated environments.

The rhizospheric microorganisms of agricultural crops play a crucial role in plant growth and nutrient cycling. In this study, we isolated two Streptomyces strains, Streptomyces sp. LM32 and Streptomyces sp. LM65, from the rhizosphere of Vitis vinifera L. We then conducted genomic analysis by assembling, annotating, and inferring phylogenomic information from the whole genome sequences. Streptomyces sp. strain LM32 had a genome size of 8.1 Mb and a GC content of 72.14%, while Streptomyces sp. strain LM65 had a genome size of 7.3 Mb and a GC content of 71%. Through ANI results, as well as phylogenomic, pan-, and core-genome analysis, we found that strain LM32 was closely related to the species S. coelicoflavus, while strain LM65 was closely related to the species S. achromogenes subsp. achromogenes. We annotated the functional categories of genes encoded in both strains, which revealed genes involved in nitrogen and phosphorus metabolism. This suggests that these strains have the potential to enhance nutrient availability in the soil, promoting agricultural sustainability. Additionally, we identified gene clusters associated with nitrate and nitrite ammonification, nitrosative stress, allantoin utilization, ammonia assimilation, denitrifying reductase gene clusters, high-affinity phosphate transporter and control of PHO regulon, polyphosphate, and phosphate metabolism. These findings highlight the ecological roles of these strains in sustainable agriculture, particularly in grapevine and other agricultural crop systems.