Abstract

The fungi are living organisms of great importance around agriculture, food industry, and the  pharmaceutical industry. The usage of these microorganisms in agriculture is for the biocontrol of diseases in plants of commercial interest. Some yeasts can fight phytopathogens through secondary metabolites produced, inhibiting their development. Some species show positive results in the control of pathologies in different cultures. Yeasts have been used as biocontrol agents, and among them, a Lachancea (Kluyveromyces) thermotolerans, which is present in plants (such as grapes), soil and insects, can be adapted to different environments and, possibly perform biological control, although it is not known its mode of action. This work aimed to analyze and identify secondary metabolites used by the yeast L. thermotolerans CCMA 0763 isolated from commercial grapes in the Agricultural Microbiology Laboratory (Federal University of Lavras-MG/BR), using the analytical method of Ultra High-Efficiency Liquid Chromatography (UHPLC) (HRMS) and Tandem Mass Spectrometry (MS/MS). Four heterocyclic compounds of the Alkaloids class were identified, three (03) natural: 4-Hydroxyquinoline, Xanthine and Calistegine A3, and one (01) synthetic: Clausehainanine C. Therefore, these compounds can be tested against phytopathogenic microorganisms.

Key words: Yeast, biological control, secondary metabolite, ultra high-efficiency liquid chromatography (UHPLC), mass spectrometry.