1. Pichia cactophila and Kluyveromyces lactis are Highly Efficient Microbial Cell Factories of Natural Amino Acid-Derived Aroma Compounds
- Author
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Monika Borkowska, Ewelina Celińska, Barbara Słoma, Paulina Korpys, Radosław Bonikowski, Monika Kubiak, Włodzimierz Grajek, Anna Dobrowolska, and Wojciech Białas
- Subjects
0301 basic medicine ,non-conventional yeast ,aroma ,bioconversion ,2-phenylethanol ,isoamyl alcohol ,2-phenylethyl acetate ,Bioconversion ,Pharmaceutical Science ,Article ,Analytical Chemistry ,03 medical and health sciences ,chemistry.chemical_compound ,Drug Discovery ,Aromatic amino acids ,Food science ,Physical and Theoretical Chemistry ,Aroma ,Kluyveromyces lactis ,chemistry.chemical_classification ,biology ,Chemistry ,Organic Chemistry ,food and beverages ,Ripening ,biology.organism_classification ,Isoamyl alcohol ,Yeast ,Amino acid ,030104 developmental biology ,Chemistry (miscellaneous) ,Molecular Medicine - Abstract
The pivotal role of non-conventional yeast (NCY) species in formation of valuable aroma compounds in various food commodities is widely acknowledged. This fact inspires endeavors aiming at exploitation of food-derived NCYs as biocatalysts in natural aromas production. In this study, we isolated, characterized and evaluated aroma-producing capacity of two NCY representatives—Pichia cactophila 7.20 and Klyuveromyces lactis 6.10 strains. The strains were isolated from food-related habitats—goat-milk regional cheese and Swiss-type ripening cheese, respectively. Aroma profiles generated by the two strains cultured in a general rich medium were analyzed through solvent extraction and GC-MS analysis of the compounds retained in the culture media. Finally, the strains were tested in bioconversion cultures with branched chain- or aromatic amino acids as the sole nitrogen source, to assess capability of the strains towards formation of amino acid-derived aromas. The results showed extraordinary capacity of both strains for production of 2-phenylethanol (at more than 3 g/L) and isoamyl alcohol (approx. 1.5 g/L). A distinctive trait of 2-phenylethyl acetate synthesis at high concentrations (0.64 g/L) was revealed for P. cactophila 7.20 strain. Highly valued disulfide dimethyl as well as methionol acetate were identified amongst the aroma compounds synthesized by the strains.
- Published
- 2018