Aureobasidium pullulans as biological control agent: modes of action

Di Francesco, Alessandra (2015) Aureobasidium pullulans as biological control agent: modes of action, [Dissertation thesis], Alma Mater Studiorum Università di Bologna. Dottorato di ricerca in Scienze e tecnologie agrarie, ambientali e alimentari, 27 Ciclo. DOI 10.6092/unibo/amsdottorato/7156.
Documenti full-text disponibili:
Documento PDF (English) - Richiede un lettore di PDF come Xpdf o Adobe Acrobat Reader
Download (8MB) | Anteprima


The postharvest phase has been considered an environment very suitable for successful application of biological control agents (BCAs). However, the tri-interaction between fungal pathogen, host (fruit) and antagonist is influenced by several parameters such as temperature, oxidative stresses, oxygen composition, water activity, etc. that could be determining for the success of biocontrol. Knowledge of the modes of action of BCAs is essential in order to enhance their viability and increase their potentialities in disease control. The thesis focused on the possibility to explain the modes of action of a biological control agent (BCA): Aureobasidium pullulans, in particular the strains L1 and L8, control effective against fruit postharvest fungal pathogen. In particular in this work were studied the different modes of action of BCA, such as: i) the ability to produce volatile organic compounds (VOCs), identified by SPME- gas chromatography-mass spectrometry (GC-MS) and tested by in vitro and in vivo assays against Penicillium spp., Botrytis cinerea, Colletotrichum acutatum; ii) the ability to produce lytic enzymes (exo and endo chitinase and β-1,3-glucanase) tested against Monilinia laxa, causal agent of brown rot of stone fruits. L1 and L8 lytic enzymes were also evaluated through their relative genes by molecular tools; iii) the competition for space and nutrients, such as sugars (sucrose, glucose and fructose) and iron; the latter induced the production of siderophores, molecules with high affinity for iron chelation. A molecular investigation was carried out to better understand the gene regulation strictly correlated to the production of these chelating molucules. The competition for space against M. laxa was verified by electron microscopy techniques; iv) a depth bibliographical analysis on BCAs mechanisms of action and their possible combination with physical and chemical treatments was conducted.

Tipologia del documento
Tesi di dottorato
Di Francesco, Alessandra
Dottorato di ricerca
Scuola di dottorato
Scienze agrarie
Settore disciplinare
Settore concorsuale
Parole chiave
Aureobasidium pullulans, Biological Control Agent, Postharvest Fungal Pathogens, Volatile Organic Compounds, Lytic Enzymes, Nutrient and Space Competition
Data di discussione
8 Maggio 2015

Altri metadati

Statistica sui download

Gestione del documento: Visualizza la tesi