Biological treatments of manure and sewage sludge and their impacts on antimicrobial agents and their resistance genes

• Grant number: 19/24182-7
• Support Opportunities: Regular Research Grants
• Start date: February 01, 2021
• End date: January 31, 2024
• Field of knowledge: Engineering - Sanitary Engineering - Environmental Sanitation
• Agreement: CONFAP - National Council of State Research Support Foundations
• Principal Investigator: Jussara Borges Regitano
• Grantee: Jussara Borges Regitano
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil
• Associated researchers: Rafael Marques Pereira Leal

Abstract

The growing demand for fertilizers worldwide associated with the government's call for production processes more friendly to the environment have led to the search for increasingly sustainable mechanisms of goods production, especially in relation to food. In this sense, the use of rural and urban organic wastes, which previously would be destined to landfills, soils and water bodies, in agricultural as sources of nutrients for plants and microrganisms activities is essential. However, the use of organic wastes in agriculture, such as animal manures and sewage sludges, which are produced in large amounts under our conditions, without proper pre-treatment for sanitation, can become an important path of environmental contaminants, with negative implications for the entire food chain. Among the contaminants, the emerging ones, such as antimicrobials and their resistance genes, are those that need more studies, especially under tropical conditions. The chemical attributes (of the organic matrix and the contaminants) and the type of biological treatment to which these wastes are submitted will directly impact their environmental behavior and fate. Thermophilic composting can be a safe and viable approach to treating these materials as it can promote degradation of these contaminants. In parallel, little is known about the impact of the distinct, but most common biological treatments adopted in the sewage treatment plants on antibiotics dissipation and their resistome composition. Therefore, this research aims to study how different biological treatment concepts, such as composting and redox conditions employed in wastewater treatment plants, affect dissipation of antimicrobials and their resistance genes, usually found in agricultural areas where animal manures and sewage sludges are used. These studies are needed to elucidate effective measures to enable the safe use of these residues in agriculture, minimizing exposure to antimicrobials capable of stimulating the occurrence of resistant genes in the environment. (AU)