Isolation, Genomic Characterization and Biotechnological Potential of Culturable Bacteria from Metal-Rich and Organic Soils of La Soledad Dam, Guanajuato, Mexico
TL;DR
Findings highlight the potential biotechnological relevance of culturable bacterial isolates recovered from historically mining-impacted soils and provide genomic resources for future studies on environmental remediation, sustainable agriculture, and industrial biotechnology.
Abstract
Abstract This study aimed to isolate, characterize, and evaluate the biotechnological potential of culturable bacteria recovered from metal-rich and organic soils of La Soledad Dam, Guanajuato, Mexico. Soil samples composed of fine sediments and decomposing organic matter were cultured on nutrient agar, and representative bacterial isolates were characterized using morphological, microscopic, phylogenomic, and whole-genome analyses. Geochemical characterization of the soils revealed elevated concentrations of iron and manganese oxides associated with the historical mining activity of the study area. Three bacterial strains were identified through genome-based phylogenomic analyses as Microbacterium maritypicum, Lysinibacillus fusiformis, and Bacillus wiedmannii. To our knowledge, this is the first report describing the isolation and genome-based characterization of these species from La Soledad Dam. Genome mining using antiSMASH identified biosynthetic gene clusters and genes potentially associated with carbohydrate metabolism, secondary metabolite biosynthesis, heavy-metal resistance, plant growth-promoting traits, and antimicrobial compounds. Functional assays provided experimental support for selected genome-based predictions. Microbacterium maritypicum was able to grow in mineral medium supplemented with naphthalene at concentrations up to 15 mg L−1, indicating tolerance to this polycyclic aromatic hydrocarbon. Lysinibacillus fusiformis colonized low-density polyethylene (LDPE) films and promoted measurable polymer weight loss, with greater LDPE weight loss observed following thermal and ultraviolet pretreatment of the polymer. These findings highlight the potential biotechnological relevance of culturable bacterial isolates recovered from historically mining-impacted soils and provide genomic resources for future studies on environmental remediation, sustainable agriculture, and industrial biotechnology.