title: Effect of storage and processing on plasmid, yeast and plant genomic DNA stability in juice from genetically modified oranges.
abstract: Recombinant DNA technology is an important tool in the development of plant varieties with new favourable features. There is strong opposition towards this technology due to the potential risk of horizontal gene transfer between genetically modified plant material and food-associated bacteria, especially if genes for antibiotic resistance are involved. Since horizontal transfer efficiency depends on size and length of homologous sequences, we investigated the effect of conditions required for orange juice processing on the stability of DNA from three different origins: plasmid DNA, yeast genomic DNA and endogenous genomic DNA from transgenic sweet orange (C. sinensis L. Osb.). Acidic orange juice matrix had a strong degrading effect on plasmid DNA which becomes apparent in a conformation change from supercoiled structure to nicked, linear structure within 5h of storage at 4 degrees C. Genomic yeast DNA was degraded during exposure to acidic orange juice matrix within 4 days, and also the genomic DNA of C. sinensis suffered degradation within 2 days of storage as indicated by amplification results from transgene markers. Standard pasteurization procedures affected DNA integrity depending on the method and time used. Our data show that the current standard industrial procedures to pasteurize orange juice as well as its acidic nature causes a strong degradation of both yeast and endogenous genomic DNA below sizes reported to be suitable for horizontal gene transfer.
authors.affiliation: Agricultural Science and Technology Department, Genetics, Universidad Politécnica de Cartagena, 30203 Cartagena, Spain. julia.weiss@upct.es
authors.forename: Julia
authors.initials: J
authors.lastname: Weiss
authors.forename: Maria
authors.initials: M
authors.lastname: Ros-Chumillas
authors.forename: Leandro
authors.initials: L
authors.lastname: Peña
authors.forename: Marcos
authors.initials: M
authors.lastname: Egea-Cortines
mesh_terms: D001628:Beverages / Q000032:analysis*; D032084:Citrus sinensis / Q000235:genetics*; D018744:DNA, Plant / Q000032:analysis*; D004274:DNA, Recombinant / Q000032:analysis*; D005516:Food Microbiology; D005519:Food Preservation; D030841:Food, Genetically Modified; D005525:Food-Processing Industry / Q000379:methods; D022761:Gene Transfer, Horizontal; D042822:Genomic Instability; D006863:Hydrogen-Ion Concentration; D030821:Plants, Genetically Modified / Q000235:genetics; D010957:Plasmids / Q000032:analysis / Q000235:genetics
chemical_list: D018744:DNA, Plant; D004274:DNA, Recombinant