Prospecting and evaluating antimicrobial resistance and metal tolerance of microorganisms isolated from cave soil in Serra de Carajás – PA

Abstract

The microbial communities present in cavities, especially in iron lithology environments, remain largely unknown. The isolation and characterization of cave microbiota are essential for identifying new species and obtaining substances of biotechnological relevance, such as antimicrobial compounds and microorganisms capable of bioremediating heavy metals. The objective of this study was to evaluate the antimicrobial activity and metal tolerance of bacteria isolated from the soil of caves GEM-1423 and GEM-1462 located in the Campos Ferruginosos National Park, in Serra de Carajás, Pará, Brazil. The bacteria were isolated from soil in different zones of the caves (photic, penumbra and aphotic) and subjected to antimicrobial susceptibility tests using the disk-diffusion technique and assessment of tolerance to metals by determining the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (CBM). Regarding the resistance profile, the bacteria showed high resistance to the antimicrobials Trimethoprim, Ampicillin and Amoxicillin. All bacteria showed tolerance to the metals Fe, Mn, Pb, Mg and K. These data are fundamental to understanding the potential of these microbial communities in iron lithology environments, thus contributing to the advancement of knowledge around ​​cave microbiology, with implications significant for environmental biotechnology and conservation of underground ecosystems.