Control de mohos toxigénicos mediante la proteína PgAFPInfluencia en el metabolismo, proteoma y síntesis de micotoxinas

  1. Josué Delgado Perón
Supervised by:
  1. Miguel Ángel Asensio Pérez Director
  2. Félix Núñez Breña Director

Defence university: Universidad de Extremadura

Year of defence: 2016

  1. Andrés Otero Carballeira Chair
  2. Rebecca A. Owens Secretary
  3. Alicia Rodríguez Jiménez Committee member
  4. Margarita Medina Fernández-Regatillo Committee member
  5. Sonia Marín Sillué Committee member

Type: Thesis

Teseo: 406982 DIALNET


Molds growing on dry-cured meat products can produce mycotoxins, which are considered as a hazard for consumers� health. The antifungal protein PgAFP, produced by Penicillium chrysogenum isolated from dry-cured ham, inhibits the development of toxigenic fungi both on culture medium and on dry-fermented sausage for a limited period of time. To enhance its antifungal effect and the inhibition on mycotoxin production, the combination of PgAFP with D. hansenii and Pedicoccus acidilactici was assayed. The combined treatment with PgAFP and D. hansenii provided a remarkable inhibitory effect on growth and mycotoxin production of Aspergillus flavus y Aspergillus parasiticus on dry-fermented sausage and cheese. Thus, it can be proposed as protective culture. The mechanism of action of PgAFP was studied through comparative proteomics. The effect of PgAFP on A. flavus was multifactorial, including increase permeability, lower chitin content, increase of reactive oxygen species and apoptosis/necrosis events mediated by lower quantities of G-protein and Rho1. A decrease of proteins involved in aflatoxin biosynthesis was also noticed. A. flavus grown with CaCl2 was not inhibited by PgAFP, showing no detrimental signs. However, A. flavus proteome displayed altered, where higher calcineurin, G-protein, and ?-glutamyltranspeptidase levels combat oxidative stress and impede apoptosis. Thus, CaCl2 does not impede PgAFP-A. flavus interaction. A PgAFP-resistant Penicillium polonicum neither showed detrimental signs, and its proteome displayed a raised levels of Rho1, leading to higher chitin deposition to counteract the PgAFP antifungal effect. Decreasing the chitin quantity on hyphae, the antifungal effect of PgAFP is maximized