Engineering a Safe GMM for Food

New fodder for the continuing biotech food debate has been provided with the recent release of the long awaited National Academy of Sciences report “Environmental Effects of Transgenic Plants: The Scope and Adequacy of Regulation”. Undoubtedly, both proponents and detractors alike will find plenty in this comprehensive document to support their own positions.

Until recently, most of the attention in this debate has been focused on issues related to the safety of biotechnology derived crops. In fact, the recent FDA proposed rule “Premarket Notice Concerning Bioengineered Foods”, released January 18, 2001, deals exclusively with biotechnology derived food crops. However, the first use of food biotechnology was with genetically modified microorganisms (GMMs) for the production of food processing aids, specifically, chymosin for use in cheese. The use of GMMs for food processing aids and ingredients has a long history of safe use, with its potential only beginning to be realized after more than ten years of increasing application. Perhaps the most innovative and exciting use of this technology is for the engineering of probiotics (e.g. live GMM cultures for consumption as/in food). As it stands now, GMMs and GMM derived food ingredients and processing aids can be determined Generally Recognized As Safe (GRAS) prior to marketing in the United States.

The GRAS safety assessment of several GMM-derived food processing aids and food ingredients is well established with precedents set by similar determinations for numerous food processing enzymes. Essentially, the safety assessment of GMMs should include detailed descriptions of:

1. host (recipient) microorganism(s);

2. genetic modification(s);

3. phenotypic and biochemical characterization of the new GMM and expressed products;

4. manufacturing process (cGMP) and specifications;

5. expected daily intake (EDI) levels and resulting dietary/ nutritional impact(s) and

6. safety assessment (toxicology) qualifying the appropriate test(s) needed for purified product (protein, non-protein) or whole GMM.

Clearly, the specific safety tests will depend on what the final food ingredient product is to be, namely whether a purified protein or molecule, or a whole GMM. Moreover, the safety testing will need to be tailored according to whether the GMM is to be consumed as a viable organism (probiotic) or a nonviable organism.

Common safety issues associated with GMMs are their potential for allergic reactions, competition with natural organisms and environmental release. Protein allergenicity issues are not unique for GMMs and are dealt with according to established methods such as protein stability, allergen homology and serum screening. Probiotics, on the other hand, present a unique challenge due to their potential effects on the endogenous gastrointestinal microflora population from consumption of live GMMs. In addition, potential impact from GMM environmental release may need to be addressed.

#geneticmodification