Inibição de Salmonella Typhimurium por bovicina HC5 associada a agentes quelantes e tensoativos

• Ano de defesa: 2009
• Autor(a) principal: Prudêncio, Claúdia Vieira
• Orientador(a): Vanetti, Maria Cristina Dantas
• Banca de defesa: Passos, Flávia Maria Lopes , Pinto, Cláudia Lúcia de Oliveira , Ferreira, Sukarno Olavo
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Mestrado em Microbiologia Agrícola
• Departamento: Associações micorrízicas; Bactérias láticas e probióticos; Biologia molecular de fungos de interesse
• País: BR
• Palavras-chave em Português: Salmonella; Bovicina HC5; Biocontrole
• Palavras-chave em Inglês: Salmonella; Bovicin HC5; Biocontrol
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::CIENCIA E TECNOLOGIA DE ALIMENTOS::CIENCIA DE ALIMENTOS::MICROBIOLOGIA DE ALIMENTOS
• Link de acesso: http://locus.ufv.br/handle/123456789/5318

One of the new strategies developed to preserve food is bioconservation and within this concept, the use of bacteriocins stands out for these ingredients are considered natural food. Gram-negative bacteria are generally resistant to the action of bacteriocins of gram-positive for these are less permeable due to the presence of the outer membrane, which acts as an effective barrier. The aim of this study was to evaluate the effectiveness of bovicina HC5 associated with chelating agents or surfactants on the growth of Salmonella Typhimurium. In this work, the growth of Salmonella was evaluated in tests on microplates and by count of viable number (CFU) on agar plate. The morphology of the cells was observed in scanning electron microscopy and atomic force and leakage of potassium was measured by flame spectrophotometry. Bovicin HC5 did not significantly alter the growth of Salmonella Typhimurium, but when combined with chelating agents or surfactants, it promoted inhibition or reduction in growth rate. The association of bovicin HC5 and EDTA exerted greater antimicrobial effect by suppressing the growth of Salmonella, even with the lower concentration of bovicin HC5 that was used, 50 AU.mL-1. The association of bovicin HC5 with chelating agents, diethanolamine, gluconic acid, nitrilotriacetic acid, lactic acid and sodium citrate and the surfactant, Tween 80 and ramnolipid, reduced the growth rate. Potassium phosphate and calcium acetate did not have antimicrobial effect, even associated with bovicin HC5. Treatment with bovicin HC5, regardless of the presence of EDTA, causes leakage of potassium. Concentrations of 50 AU.mL-1 of bovicin HC5 associated with low concentrations of EDTA (1,6 mmol.L-1) exerted a bactericidal effect on Salmonella Typhimurium with a reduction of three logarithmic cycles on cell viable number. Cells treated with EDTA and bovicin HC5 and were visualized by atomic force microscopy and showed changes in their cell envelope, with a reduction in height and increase in roughness. These data demonstrated the possibility of using bovicin HC5 in control of Salmonella Typhimurium from that associated with substances that dismantled the outer membrane.