https://doi.org/10.17113/ftb.56.02.18.5582 

Properties and Fermentation Activity of Industrial Yeasts Saccharomyces cerevisiae, S. uvarum, Candida utilis and Kluyveromyces marxianus Exposed to AFB₁, OTA and ZEA

Željko Jakopović^1*, Karla Hanousek Čiča², Jasna Mrvčić², Irina Pucić³, Iva Čanak¹, Jadranka Frece¹, Jelka Pleadin⁴, Damir Stanzer², Slaven Zjalić⁵ and Ksenija Markov¹

¹Department of Biochemical Engineering, Faculty of Food Technology and Biotechnology, University of Zagreb, Pierottijeva 6, HR-10000 Zagreb, Croatia
²Department of Food Engineering, Faculty of Food Technology and Biotechnology, University of Zagreb, Pierottijeva 6, HR-10000 Zagreb, Croatia
³Department of Materials Chemistry, Ruđer Bošković Institute, Bijenička cesta 54, HR-10000 Zagreb, Croatia
⁴Laboratory for Analytical Chemistry, Croatian Veterinary Institute, Savska cesta 143, HR-10000 Zagreb, Croatia
⁵Department of Ecology, Agronomy and Aquaculture, University of Zadar, M. Pavlinovića 1, HR-23000 Zadar, Croatia

Article history:
Received: 27 October 2017
Accepted: 17 January 2018

Key words:
mycotoxins, yeasts, yeast growth, yeast morphology, fermentation, FTIR

Summary:
In this paper the effect of aflatoxin B1, ochratoxin A and zearalenon on morphology, growth parameters and metabolic activity of yeasts Saccharomyces cerevisiae, Saccharomyces uvarum, Candida utilis and Kluyveromyces marxianus was determined. The results showed that the three mycotoxins affected the morphology of all these yeasts, primarily the cell diameter, but not their final cell count. Fourier transform infrared spectroscopy showed that the yeast membranes bound the mycotoxins, C. utilis in particular. The cell membranes of most yeasts underwent denaturation, except S. uvarum exposed to ochratoxin A and zearalenone. In the early stage of fermentation, all mycotoxin-exposed yeasts had lower metabolic activity and biomass growth than controls, but fermentation products and biomass concentrations reached the control levels by the end of the fermentation, except for C. utilis exposed to 20 μg/mL of zearalenone. The adaptive response to mycotoxins suggests that certain yeasts could be used to control mycotoxin concentrations in the production of fermented food and beverages.

*Corresponding author:    +38514605123
                                             zjakopovic@pbf.hr