Utilização de mutantes para identificação de genes envolvidos na produção de biofilmes de Listeria monocytogenes

• Author(s): Santos, Ana Rita Rodrigues dos
• Date: 2015
• Persistent ID: http://hdl.handle.net/10400.5/8513
• Origin: Repositório da UTL
• Subject(s): Listeria monocytogenes; biofilm; mutant; exoproteins; flagella; secretion systems
• Document Type: Master thesis
• Language: Portuguese
• Advisor(s): Brito, Maria Luísa de Castro; Lourenço, António Abreu Afonso
• Contributor(s): Repositório da Universidade de Lisboa

Description

Mestrado em Engenharia Alimentar - Instituto Superior de Agronomia

Listeria monocytogenes is a bacteria considered difficult to eradicate in food industry duo to its ability to form biofilms. The ability of biofilm formation was evaluated in five L. monocytogenes strains (the wild type EGDe and four mutants of this strain, at gene fliF, fliI, tatAC and lmo0364). The Tat system is responsible for secretion of proteins in their final phase of conformation. The lmo0364 gene encodes for a transcrptional regulator that has been poorly studied. The flagella are proteins involved in the mobility of the bacteria and play a crucial role in the initial and subsequent steps of biofilm formation and cell attachment. The crystal violet, the ruthenium red and the enumeration of cells in stainless steel assays were used. The biofilm production was evaluated at 25 ° C and 37 ° C in TSB and MWB medium. The results indicate a reduced ability of flagellar mutants to produce biofilm whencompared to its wild type, showing the importance of flagella to produce biofilm in L. monocytogenes