Yeasts – a farmer's natural friend

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Professor Urszula Wachowska, PhD
Is it possible that yeast, i.e. microorganisms well-known in the baking, brewing and alcohol-distilling industries, could be a poison? Indeed, they can; and this poison may be very useful in farming. This has been proven, for the first time in Poland and Europe, by Professor Urszula Wachowska, PhD. at the University of Warmia and Mazury (UWM).

Professor Urszula Wachowska, PhD, is a phytopathologist employed at the Department of Entomology, Phytopathology and Molecular Diagnostics, Faculty of Environmental Management and Agriculture. Professor Wachowska has obtained a Polish patent for the first, in both Poland and Europe, biological preparation for combating the most common wheat pathogens, i.e. fungi of the Fusarium culmorum and Zymoseptoria tritici species.

She studies, inter alia, crop-infecting microorganisms which pose a threat to human health, and seeks ways to prevent their development. Besides bacteria, yeast are the most widespread microorganisms found on cereal leaves, ears, and grains. Professor Wachowska developed a particular interest in the yeast found on wheat grains and decided to investigate which particular species settled on them. She received a grant for this study from the National Science Centre. Two PhD students, Anna Stasiulewicz-Paluch, PhD, Eng., and Katarzyna Kucharska, PhD, Eng., assisted Professor Wachowska in the implementation of the grant project.

During the study, Professor Wachowska noted that under in vitro conditions, an inhibition zone was formed in the vicinity of certain yeast colonies, within which no pathogens developed. After a thorough study she discovered that yeast secreted fungicidal compounds.

“I began to wonder whether I would succeed in culturing yeast strains which would limit the development of plant pathogens. By applying numerous culture, microscopic, and molecular techniques, we selected about 20 strains characterised by rapid growth on artificial mediums, with a high rate of growth on wheat seedling leaves and antagonistic action against pathogens”, says Professor Wachowska.

Later on, she investigated how the strains which had successfully passed laboratory tests developed under natural conditions. She prepared an aqueous suspension of these strains and sprayed it onto plants growing on experimental plots, focusing on the following winter wheat varieties: Bogatka, Tonacja, Skagen, Muszelka and Komnata. The effect confirmed her expectations. The yeasts contained in a biological preparation rapidly colonised wheat and reduced the deoxynivalenol content of wheat grains (deoxynivalenol is one of the fusarium mycotoxins most commonly found in grains). In 2014, Professor Wachowska applied for a patent for her biological preparation and the method for its application at the Patent Office of the Republic of Poland, and was granted a patent last year.

This is the first biological preparation in both Poland and Europe for combating the most common wheat pathogens, i.e. fungi of the Fusarium culmorum and Zymoseptoria tritici species.

“My biological preparation, as opposed to the fungicides currently used for chemical protection, can be used during the flowering of wheat and immediately before the grain harvest. It is not harmful to humans and no pre-harvest interval is required for it. It is also completely safe for the environment and needs no specific disposal conditions. Although it can be quite easily produced, the preparation is slightly less effective compared to chemical agents. My method for its production is not industrial, so I cannot really say much about the actual production costs”, adds Professor Wachowska.

Lech Kryszałowicz