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Development of an Effective Enzyme Product to Degrade Trichothecene Mycotoxins in Contaminated Grains

Investigators
Zhou, Ting
Institutions
Agriculture and Agri-Food Canada
Start date
2006
End date
2008
Objective
Mycotoxin contamination of food and feed ingredients has been an ongoing and serious threat to human health as well as to food and livestock industries. However, preventing food or feed contamination by mycotoxins is not always feasible or practical. Therefore developing and implementing innovative mycotoxin detoxification methods are essential in food safety management, and are particularly important in Ontario where grain production and cereal-based food industries are significant agricultural sectors. This research will focus on the development of an enzyme product that is able to effectively degrade and thus detoxify trichothecene mycotoxins, including deoxynivalenol (DON or vomitoxin) and T-2 toxin, by transforming them into compounds several hundred times less toxic. In an ongoing research project, supported by both Agriculture and Agri-Food Canada (AAFC) and Ontario Pork, our multidisciplinary team has successfully identified several bacterial isolates that can completely transform trichothecene toxins into much less toxic forms. In this OMAFRA supported project, the trichothecene-transforming bacterial isolates will be characterized for their capability to produce trichothecene degrading enzyme(s). The factors affecting growth of the bacterial isolates, including culture conditions, growth rate and requirements, and utilization of nutrient sources, etc. will be examined. The efficiency of trichothecene-degradation by the bacterial isolates and the location of enzyme activity will also be determined. The promising bacterial isolates will subsequently be tested in scale-up fermentation experiments. A strategy for isolation of trichothecene-degrading enzyme(s) will be developed upon determining the characteristics of enzyme activity, which will include the use of a variety of biochemical and chromatography techniques. The enzyme product obtained from these studies will be evaluated for its usefulness in trichothecene mycotoxin degradation in food and feed ingredients. The success of this project will deliver: i) an effective enzyme product capable of degrading trichothecenes at a laboratory scale; ii) essential data for future development of commercial enzyme products; and iii) potential identification of the trichothecene degrading gene.
More information
Expected Impact of Project Outcomes on Food Safety in Ontario: DON and T-2 toxin are members of the trichothecene family, one of the most important mycotoxin groups, and are very frequently encountered in human foods, e.g. corn meal and granola. The presence of mycotoxins in food designated for human consumption is a food safety hazard and threat to human health. In Canada, when mold-infested corns and other grains such as wheat and barley are brought to a country elevator, they will normally be downgraded or rejected. In 2003, DON was detected in 63% of samples of cereal-based infant foods from the Canadian retail market. Ontario produces about 200 million bushels of grain corn annually and mycotoxin contamination remains a major challenge facing the industry. During 1980-1995, DON occurrence in Ontario corn varied from 12.5% to 100%, and the levels ranged from 0.02 to 4.09 ppm. Preventing mycotoxin contamination by pre-harvest management, including breeding for resistant varieties and use of fungicides, has not been efficacious in eliminating mycotoxins from food and feedstuff. It is expected that progress in the control of mycotoxin contamination will depend on the introduction of technologies for specific and efficient detoxification. Because trichothecene toxins are resistant to high cooking temperatures and chemical and physical degradation methods, biological detoxification has become a more promising approach. Our research team has successfully identified and isolated several bacterial isolates that can effectively detoxify trichothecene toxins through degradation. Further this project will identify and produce the degrading enzyme(s) from the bacteria so that they can be used to reduce/eliminate mycotoxins in grains and as an additive in animal feed. The project will also characterize the enzyme to enable future transgenic approaches to be developed for trichothecene degradation.

For more information, please visit the Ontario Ministry of Agriculture, Food & Rural Affairs (OMAFRA) Food Safety Research Program.

Funding Source
Ontario Ministry of Agriculture Food and Rural Affairs
Project number
SF6050
Categories
Natural Toxins
Food Preparation and Handling
Bacterial Pathogens
Chemical Contaminants
Commodities
Meat, Poultry, Game
Grains, Beans, Legumes