Evaluation of bacterial resistance to heavy metals, co-resistance to antimicrobials, and bioremediation potential

• Grant number: 24/15760-5
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Start date: July 01, 2025
• End date: February 28, 2027
• Field of knowledge: Biological Sciences - Microbiology - Applied Microbiology
• Principal Investigator: André Pitondo da Silva
• Grantee: Miguel Augusto de Moraes
• Host Institution: Universidade de Ribeirão Preto (UNAERP). Campus Ribeirão Preto. Ribeirão Preto , SP, Brazil

Abstract

Heavy metals are chemical elements with relatively high density and toxic characteristics at relatively low concentrations. Among the most well-known are lead, mercury, cadmium, arsenic, and chromium. These elements are naturally present in the Earth's crust and can be found in ores. However, human activities, particularly mining operations, have significantly increased the concentration of these metals in the environment. Heavy metals released during mining can contaminate soil, water, and air, posing serious risks to human health and the environment. Bioremediation of heavy metals is a technique that employs living organisms, such as plants, microorganisms, and fungi, to remove, reduce, or transform heavy metal contaminants in the environment. This approach is a promising and ecologically sustainable alternative for remediating areas contaminated by heavy metals, especially those affected by mining activities. Bacteria play a significant role in removing these metals from the environment, either by utilizing them as metabolic substrates or by adsorbing them from the surroundings. Another important aspect is bacterial co-resistance to heavy metals and antimicrobials. Co-resistance to heavy metals and antimicrobials is an increasing concern due to its direct impact on public health and the environment. Environments contaminated with heavy metals can act as reservoirs for the dissemination of resistance genes, thereby exacerbating the problem of antimicrobial resistance. In this context, the objective of this study is to quantify the concentration of heavy metals, assess the resistance and co-resistance profiles to both heavy metals and antimicrobials, and evaluate the bioremediation potential of bacteria isolated from alluvial sediments potentially contaminated with heavy metals in the Central Region of the State of Minas Gerais. Phenotypic and molecular techniques will be employed to assess the isolates' tolerance to metals, their bioremediation potential, and their resistance to antimicrobials. Thus, by the end of the study, the goal is to identify strains with potential for safe bioremediation applications and to investigate the correlations between anthropogenic activities and the studied microorganisms.