Isolamento, identificação e caracterização de fungos e bactérias resistentes a metais potencialmente tóxicos em solos contaminados

• Ano de defesa: 2025
• Autor(a) principal: Amorim, André Luiz Fernandes de
• Outros Autores: [e-mail]
• Orientador(a): Salomão, André Luís de Sá
• Banca de defesa: Silva, Andressa Andrade Alves da , Valadão, Izabella Christynne Ribeiro Pinto , Bufalo, Tatiana Cardoso e , Cunha, Priscila Maria de Oliveira Muniz
• Tipo de documento: Tese
• Tipo de acesso: Acesso embargado
• Idioma: por
• Instituição de defesa: Universidade do Estado do Rio de Janeiro
• Programa de Pós-Graduação: Programa de Pós-Graduação em Engenharia Ambiental
• Departamento: Centro de Tecnologia e Ciências::Faculdade de Engenharia
• País: Brasil
• Palavras-chave em Português: Engenharia ambiental; Solos - Poluição; Metais - Toxicologia; Fungos do solo; Bactérias; Biorremediação
• Palavras-chave em Inglês: Environmental engineering; Soil pollution; Metals - Toxicology; Soil fungi; Bacteria; Bioremediation
• Área do conhecimento CNPq: ENGENHARIAS::ENGENHARIA SANITARIA::SANEAMENTO AMBIENTAL::QUALIDADE DO AR, DAS AGUAS E DO SOLO
• Link de acesso: http://www.bdtd.uerj.br/handle/1/25346

Contamination by potentially toxic metals represents a persistent environmental problem, requiring sustainable strategies for its mitigation. Microorganisms, such as fungi and bacteria, constitute a promising and sustainable approach for metal remediation processes and soil microbiota recovery, as they can transform, immobilize, or remove metals. The objective of this thesis was to investigate the potential of fungi from the Clonostachys genus and a bacterial consortium composed by Pseudomonas sp., Snodgrassella sp., Agrobacterium sp., and Stenotrophomonas sp. in the bioremediation of metal-contaminated soils, focusing on copper (Cu), lead (Pb), and zinc (Zn). The methodology, developed collaboratively, involved soil collection from 12 sampling points, followed by analyses of total and bioavailable metals. Subsequently, microbial stimulation methods were developed using Mycelial Networks, as well as Replica and Replacement techniques for selective isolation. After isolating morphologically distinct colonies, DNA extraction and genetic amplification were performed. Samples were then prepared for analysis by Fourier Transform Infrared Spectroscopy (FTIR). Next, the Minimum Inhibitory Concentration (MIC) assay was conducted. Finally, analyses were carried out using Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). FTIR analyses revealed alterations in bands associated with proteins, lipids, and polysaccharides, indicating mechanisms of metal complexation and cellular structural reorganization. For Cu2+, the average MIC values were 45 mg/L for fungal isolates and 30 mg/L for bacterial isolates, reaching 300 mg/L in co-cultures, demonstrating a synergistic effect. For Zn+2, the averages were 4500 mg/L (fungi), 2000 mg/L (bacteria), and 400 mg/L (co-cultures), indicating antagonism. In the case of Pb2+, an antagonistic effect was also observed, with 1000 mg/L for fungi, 3000 mg/L for bacteria, and 5 mg/L for co-cultures. ICP-OES analysis confirmed maximum average removals of 51% for Cu2+ in fungal isolates, 33% in co-cultures, and 15% in bacterial consortia. For Pb2+, removals reached 98.5%, 99.7%, and 99.77%, respectively. For Zn2+, removals of 80.28% for fungi, 23.65% for co-cultures, and 92.58% for bacteria were observed. These results demonstrate that microbial interactions significantly alter metal resistance and biosorption. It is concluded that Clonostachys sp. and the bacterial isolates exhibit high biotechnological potential in bioremediation, representing an effective, sustainable, and economically viable alternative for the recovery of contaminated soils.