Prof. Joe Cummins exposes the potential hazards of the GM wine yeast that has been approved as safe by the US Food and Drug Administration and advises against drinking US wines.
GM wine by stealth
Did you know that genetically modified (GM) wine has been marketed in the United States for the past three years?
In 2003, the United States Food and Drug Administration (FDA) designated the GM yeast strain Saccharomyces cerevisae ML01 ‘generally recognized as safe’ (GRAS). The strain included a gene for malolactic enzyme from the bacterium Oenococcus oeni and a malate permease gene from the fission yeast Schizosaccharomyces pombe. Wine making involves alcoholic fermentation via the metabolic pathways of yeast and the malolactic pathway to convert malic acid to lactic acid, to reduce the acidity of the wine. Malolactic acid fermentation is usually achieved using lactic acid bacteria, which have a permease for malic acid. Putting the two fermentation pathways in one organism seems a good idea.
The yeast ML01 was modified using a shuttle vector containing a chromosome integration cassette with genes for malolactic enzyme, malate transporter (permease), regulatory genes and a sequence directing homologous recombination at a chromosomal locus (not specified in the FDA report), and the antibiotic phleomycin gene was used as a selectable marker via another plasmid. After culturing the selected antibiotic resistant lactic-acid producing yeast, a phleomycin-sensitive lactic acid producing strain was isolated and found to contain the integrated malolactic-malate transporter genes. The original anti-phleomycin plasmid did not contain a sequence allowing it to be integrated into the yeast chromosome and the plasmid was therefore unstable and frequently lost from the yeast cell [1]. The company distributing the GM yeast, Springer Oenologie, Lesaffre Group of North America, stated that the malate transporter gene and malolactic gene were both controlled by the phosphoglycerate kinase gene (PGK1) promoter and transcription terminator. The recombinant yeast softened the wine’s ‘mouth feel’ by decreasing its acidity, and also reduces buttery flavours (diactyl) due to lactic acid secondary metabolism [2].
(MORE) http://www.i-sis.org.uk/GMwine.php
UPDATE
'Self-Cloned' Wine Yeasts Not Necessarily Safe
Yeast genetics is more precise, but altering the expression of a single native yeast gene can change the entire metabolic network in an unexpected way.
Prof. Joe Cummins http://www.i-sis.org.uk/selfclonedwineyeast.php
GM wine by stealth
Did you know that genetically modified (GM) wine has been marketed in the United States for the past three years?
In 2003, the United States Food and Drug Administration (FDA) designated the GM yeast strain Saccharomyces cerevisae ML01 ‘generally recognized as safe’ (GRAS). The strain included a gene for malolactic enzyme from the bacterium Oenococcus oeni and a malate permease gene from the fission yeast Schizosaccharomyces pombe. Wine making involves alcoholic fermentation via the metabolic pathways of yeast and the malolactic pathway to convert malic acid to lactic acid, to reduce the acidity of the wine. Malolactic acid fermentation is usually achieved using lactic acid bacteria, which have a permease for malic acid. Putting the two fermentation pathways in one organism seems a good idea.
The yeast ML01 was modified using a shuttle vector containing a chromosome integration cassette with genes for malolactic enzyme, malate transporter (permease), regulatory genes and a sequence directing homologous recombination at a chromosomal locus (not specified in the FDA report), and the antibiotic phleomycin gene was used as a selectable marker via another plasmid. After culturing the selected antibiotic resistant lactic-acid producing yeast, a phleomycin-sensitive lactic acid producing strain was isolated and found to contain the integrated malolactic-malate transporter genes. The original anti-phleomycin plasmid did not contain a sequence allowing it to be integrated into the yeast chromosome and the plasmid was therefore unstable and frequently lost from the yeast cell [1]. The company distributing the GM yeast, Springer Oenologie, Lesaffre Group of North America, stated that the malate transporter gene and malolactic gene were both controlled by the phosphoglycerate kinase gene (PGK1) promoter and transcription terminator. The recombinant yeast softened the wine’s ‘mouth feel’ by decreasing its acidity, and also reduces buttery flavours (diactyl) due to lactic acid secondary metabolism [2].
(MORE) http://www.i-sis.org.uk/GMwine.php
UPDATE
'Self-Cloned' Wine Yeasts Not Necessarily Safe
Yeast genetics is more precise, but altering the expression of a single native yeast gene can change the entire metabolic network in an unexpected way.
Prof. Joe Cummins http://www.i-sis.org.uk/selfclonedwineyeast.php