| Title: | Selection by UV Mutagenesis and Physiological Characterization of Mutant Strains of the Yeast Saprochaete suaveolens (Former Geotrichum fragrans) with Higher Capacity to Produce Flavor Compounds |
| Author(s): | Tan M; Caro Y; Sing ASC; Reiss H; Francois JM; Petit T; |
| Address: | "Laboratoire de Chimie et Biotechnologie des Produits Naturels-CHEMBIOPRO, Universite de la Reunion, 15 Avenue Rene Cassin, CEDEX 9, CS 92003, F-97744 Saint-Denis, Ile de la Reunion, France. IUT de La Reunion, Departement Hygiene, Securite, Environnement (HSE), 40 Avenue de Soweto, CEDEX 9, BP 373, F-97455 Saint-Pierre, Ile de la Reunion, France. Toulouse Biotechnology Institute (TBI), UMR-CNRS5504 & UMR-INRA 792, INSA, F-31077 Toulouse, France. Toulouse White Biotechnology, UMS:INRA INSA CNRS, 135 Avenue de Rangeuil, F-31077 Toulouse, France" |
| ISSN/ISBN: | 2309-608X (Electronic) 2309-608X (Linking) |
| Abstract: | "Yeast volatile organic compounds (VOCs), i.e. low molecular weight organic acids, alcohols and esters, are considered as potential and sustainable sources of natural aromas that can replace commonly used artificial flavors in food and other industrial sectors. Although research generally focuses on the yeast Saccharomyces cerevisiae, other so-called unconventional yeasts (NCY) are beginning to attract the attention of researchers, particularly for their ability to produce alternative panels of VOCs. With this respect, a Saprochaete suaveolens strain isolated from dragon fruit in Reunion Island was shown to produce alpha-unsaturated esters from branched-chain amino acids (BCAAs) such as isobutyl, isoamyl or ethyl tiglate, which are rarely found in other yeasts strains. Given that beta-oxidation allows the growth of S. suaveolens on BCAAs as sole carbon source, we developped a method based on UV mutagenesis to generate mutants that can no longer grow on BCAAs, while redirecting the carbon flow towards esterification of alpha-unsaturated esters. Among the 15,000 clones generated through UV irradiation, we identified nine clones unable to grow on BCAAs with one of them able to produce eight times more VOCs as compared to the wild-type strain. This higher production of alpha-unsaturated esters in this mutant strain coincided with an almost complete loss of enoyl-CoA hydratase activity of the beta-oxidation pathways and with a twofold increase of acyl-CoA hydrolase with not significant changes in the enzymes of the Ehrlich pathway. Moreover, from our knowledge, it constituted the first example of VOCs enhancement in a microbial strain by UV mutagenesis" |
| Keywords: | Saccharomyces cerevisiae Uv mutant volatile organic compounds (VOCs) yeast; |
| Notes: | "PubMed-not-MEDLINETan, Melissa Caro, Yanis Sing, Alain Shum Cheong Reiss, Heloise Francois, Jean-Marie Petit, Thomas eng Switzerland 2021/12/25 J Fungi (Basel). 2021 Nov 30; 7(12):1031. doi: 10.3390/jof7121031" |
