Matteo Braidot
In vitro rumen aflatoxin decontamination mediated by microbes.
(Supervisor: Prof. Spanghero)
Aflatoxins are a group of carbonylic compounds produced by Aspergillus spices in particular A. flavus, A. parsiticus and A. nominus. They are divided into different classes (B1, B2, G1, G2) and among them, the most toxic and cancerogenic is the B1. The contamination can happen at different stages in the supply chain: in the field, during post-harvest or during storage. In particular, the proliferation of molds is due to environmental factors that can affect their proliferation. In fact, certain conditions as high humidity, high temperature, level of oxygen, and grain integrity can promote the development of these microorganisms. If contaminate feed is used for feeding the aflatoxin B1 is metabolized and transform in aflatoxin M1 that can be secreted in milk. The presence of these toxins in milk and dairy products is regulated by the EU regulation UE N°165/2010 that establishes the legal limits. Different strategies can be put in place to manage the aflatoxin presence and they can be direct or indirect. Direct strategies regard the management of the feeds indeed the correct storage condition plays a fundamental role to prevent the Aspergillus flavus proliferation and consequently the aflatoxin B1 presence. Indirect strategies are based on the reduction of aflatoxin in milk. Adsorbent material such as clays can be employed to reduce the M1 presence in milk, but this approach can affect nutritional intake. An interesting alternative way is represented by the use of microorganisms that are studied for their capability to bind the AFM1 or in some cases their capacity of metabolize the toxin in less toxic or nontoxic compounds. An example of microorganism use for this purpose are lactic acid bacteria and yeasts. Their effects can be studied without the utilization of animals with the employ of ruminal fermentation techniques. The artificial rumen permits to simulate with high fidelity the different processes during the digestion in vivo and it reduces at minimum the variability caused by the difference in the population. These techniques are commonly used to estimate the nutritional value of animal feeds (“batch systems”) or to study the metabolic processes (“continuous system”). In this case, the ruminal fermentation systems are employed to evaluate the interaction of different species and strain of microorganisms with the toxin and their effects on the fermentation process. The aim of this project is to study some specific feeding strategies for cows that can be applied by farmers to reduce the carry-over of toxin from animals to milk. The results will be used to find a practical feeding-dietetic strategy for the detoxification of feedstuff in order to ensure the respect of the legislation limit for the aflatoxin in milk and dairy products.
Biography and contacts
Braidot Matteo was born in 1993 in Gorizia-Italy.
In 2017 he graduated in Food science technologies at the University of Udine (95/110).
In 2019 he graduated as a Master Food science technology at the University of Udine (110/110 cum laude).
In November 2019, he started the doctoral course at the PhD school “Agriculture Science and Biotechnology” at the University of Udine.