ARCHIVED - Novel Food Information
ARCHIVED - Saccharomyces cerevisiae Yeast Strain ECMo01
Health Canada has notified First Venture Technologies Corporation that it has no objection to the sale of wine yeast ECMo01 for use in the production of fermented alcoholic beverages. The Department conducted a comprehensive assessment of this microorganism according to its Guidelines for the Safety Assessment of Novel Foods. These Guidelines are based upon internationally accepted principles for establishing the safety of foods with novel traits and reflects international guidance documents in this area (eg. Codex Alimentarius Guideline for the Conduct of Food Safety Assessment of Foods Produced Using Recombinant-DNA Microorganisms). The assessment considered how this strain was developed; how it was manufactured; and the potential for the presence of any toxicants, anti-nutrients, allergens, chemical or microbiological contaminants in alcoholic beverages produced with such yeast.
The following provides a summary of the notification from First Venture Technologies, and the evaluation by Heath Canada and contains no confidential business information.
First Venture Technologies Corporation developed a wine yeast that produces fermented alcoholic beverages with reduced levels of ethyl carbamate, a suspected carcinogen in humans. Also known as urethane, traces of ethyl carbamate are commonly found in fermented alcoholic beverages such as wine and occur from the chemical reaction of ethanol with urea, which are secreted from yeast into the surrounding wine/fermentation media.
The yeast was modified using recombinant DNA techniques to result in the introduction and high expression of an additional copy of a gene already present in conventional yeast strains. This yeast strain does not contain genetic material from any other organism.
The safety assessment performed by Food Directorate evaluators was conducted according to Health Canada's Guidelines for the Safety Assessment of Novel Foods. The assessment considered how this yeast was developed; how it was manufactured; and the potential for the presence of any toxicants, anti-nutrients, allergens, and chemical or microbiological contaminants in fermented alcoholic beverages produced by this yeast.
The Food Directorate has a legislated responsibility for pre-market assessment of novel foods and novel food ingredients as detailed in Division 28 of Part B of the Food and Drug Regulations (Novel Foods). Foods derived from yeast strain ECMo01 are considered novel foods under the following part of the definition of novel foods: "c) a food that is derived from a plant, animal or microorganism that has been genetically modified such that
- the plant, animal or microorganism exhibits characteristics that were not previously observed in that plant, animal or microorganism".
2. Development of the Modified Microorganism
The yeast was developed using electroporation transformation to introduce recombinant DNA sequences into a conventional wine yeast strain. The introduced sequence consists of the DUR1,2 gene under the control of PGK1 promoter and terminator sequences for high expression. The above expression cassette was flanked by the 5' and 3' regions of the URA3 gene to allow for targeted genome insertion by homologous recombination. Known collectively as the integration cassette, the above sequences were isolated as a 9191 bp DNA fragment prior to transformation of the host strain.
3. Characterization of the Modified Microorganism
Southern blot analysis of genomic DNA from the modified yeast with specific probes demonstrated the targeted insertion of a single copy of the integration cassette at a single URA3 locus in the yeast genome. Sequence analysis has shown the integrity of the cassette, and the absence of rearrangement of any of the respective elements
The heritability and stability of the integration cassette in the modified yeast strain was verified after culturing for 100 generations by PCR screening. Additionally, the integration cassette was shown to be stable after commercial scale vinification trials.
4. Product Information
Yeast strain ECMo01 differs from its traditional counterparts by the insertion of an extra copy of the DUR1,2 gene under the control of regulatory sequences for high expression. This gene encodes urea amidolyase, a bifunctional enzyme which converts urea into ammonia and carbon dioxide. The increase in expression of the above enzyme reduces the production of ethyl carbamate indirectly by lowering the levels of urea substrates available to react with ethanol in the wine. In contrast to urea, ammonia is quickly consumed as a preferred nitrogen source by the yeast and is not secreted into the wine.
5. Dietary Exposure
The yeast does not express any novel proteins. The only up-regulated transcript is the DUR1,2 gene encoding the enzyme urea amidolyase. This protein is endogenous to the yeast proteome, which is not known to contain toxins or allergens. Given the protein degradation and clarification steps involved before commercially produced fermented alcoholic beverages are bottled, any increase in the urea amidolyase enzyme is unlikely to result in any significant differences in exposure to yeast proteins upon consumption of the final bottled product.
Wine is not consumed for its nutritional value. Consequently, no concerns have been identified with the submission from a nutritional standpoint.
7. Chemical Safety/ Toxicology
There are Canadian guidelines for maximum limits of ethyl carbamate in wines: 30 ppb in table wines, 100 ppb in fortified wines, 150 ppb in distilled spirits, 400 ppb in fruit brandies and liqueurs, and 200 ppb in sake. Analysis of wine fermented using this yeast shows an 89 % reduction in ethyl carbamate levels compared to that of the host strain. This is a result of the increased efficacy in the degradation of urea, a substrate for formation of ethyl carbamate in wine. The excess ammonia resulting from the catabolic breakdown of urea is expected to be quickly consumed by the yeast as a preferred nitrogen source, and not secreted into the wine/fermentation media.
S. cerevisieae is not known to produce any substances that are toxic or allergenic to humans. The genetic modification did not introduce any novel DNA or transgenes from any other organism. The modified yeast exhibits the same growth rates, fermentation rates, ethanol yields, and CO2 production as the host strain. Additionally, as a result of the clarification process, human exposure levels to the yeast, and proteins from the yeast, are expected to be minimal in the final bottled fermented alcoholic beverage. Consequently, no concerns have been identified with the submission from a toxicological, food additive or chemical contaminant perspective.
The yeast will be produced in the same manner as conventional wine yeast according to standard modern manufacturing practices. The microbiological specifications provided for a single batch pilot production run of instant active dry yeast did not identify any concerns with the submission from a microbiological perspective. Fermented alcoholic beverages produced with the yeast will be subject to the same standards as conventional beverages with respect to microbial contaminants.
The safety assessment conducted by Food Directorate scientific evaluators has determined that there are no safety concerns associated with the use of the ECMo01 yeast in the production of fermented alcoholic beverages. Health Canada does not raise any objections to the human food use of the yeast in the production of fermented alcoholic beverages. The yeast and the fermented alcoholic beverages derived from it should be permitted to enter the marketplace and be subjected to the same post-market standards applicable to all foods sold in Canada.
This Novel Food Information document has been prepared to summarize the opinion regarding the subject product provided by the Food Directorate, Health Products and Food Branch, Health Canada. This opinion is based upon the comprehensive review of information submitted by the petitioner according to the Guidelines for the Safety Assessment of Novel Foods.
(Également disponible en français)
For further information, please contact:
Novel Foods Section
Health Products and Food Branch
Health Canada, PL2204A1
251 Frederick Banting Driveway
Ottawa, Ontario K1A 0K9
Telephone: (613) 941-5535
Facsimile: (613) 952-6400
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