Análise dos efeitos antimicrobianos e ecotoxicológicos de nanopartículas fúngicas de ouro sobre bactérias

• Autor(a) principal: Trotta, Caterina do Valle
• Data de Publicação: 2022
• Tipo de documento: Trabalho de conclusão de curso
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/216572
• topic: Fungo filamentoso; Escherichia coli; Chlorella sp; Nanopartícula de ouro; Nanotecnologia

Gold nanoparticles (AuNPs) have attracted scientific and technological interest due to its ease of synthesis and distinctive properties attributable to its reduced size, in addition to applications such as construction of biosensors, in treatment and diagnosis of cancer, besides acting as antimicrobial agents. Physical and chemical methods are used to synthesize NPs; however, biological methods are preferred because of their ecological sources, being a green synthesis of nanoparticles (NPs) a promising and innovative field in bionanotechnology. Filamentous Fungal Bones (Ffs) are highlighted in the literature for obtaining metallic nanoparticles due to the diversity, being considered more promising. In this context, the present work aims to evaluate the antimicrobial activity of the bionanoparticle AuNP suspended and immobilized on the bacteria Escherichia coli IPT245, Pseudomonas aeruginosa IPT236 and Staphylococcus aureus IPT246 and potential toxic effects on marine microalgae Chlorella minutissima and freshwater microalgae Chlorella fusca. The AuNPs were characterized by UV-vis spectrophotometry, 'Dynamic Light Scattering’ (DLS) and Polydispersity Index (PDI) and their antimicrobial activity avaliated by Minimum Inhibitory Concentration using the pathogenic bacteria Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. The microalgae Chlorella minutissima and Chlorella fusca were used for cell density studies. In summary, the suspended AuNP showed no antibacterial activity in any concentration in which the pathogenic bacteria were exposed. In contrast, the AuNP encapsulated with chitosan-alginate exhibited antibacterial activity on the Gram-negative bacteria E. coli IPT245, and according to the results of the cell density test with the microalgae C. minutissima and C.fusca, it can be said that the use of AuNPs in aquatic environment can be considered an environmental risk, therefore the disposal of the AuNPs residues must be properly forwarded. In view of the results obtained, biosynthesis still needs to be optimized, exploring mainly factors that influence the size and time to obtain the nanomaterial in study.