Degradation and detection of transgenic Bacillus thuringiensis DNA and proteins in flour of three genetically modified rice events submitted to a set of thermal processes. (October 2015)

• Record Type: Journal Article
• Authors: Wang, Xiaofu; Chen, Xiaoyun; Xu, Junfeng; Dai, Chen; Shen, Wenbiao
• Is Part Of: Food and chemical toxicology. Volume 84(2015)
• Page Start: 89
• Page End: 98
• Publication Date: 2015-10
• Subjects: Genetically modified -- Insect-resistant rice -- DNA degradation -- Protein degradation -- Thermal processing -- GMO detection; Toxicology -- Periodicals; Food poisoning -- Periodicals; Food Poisoning -- Periodicals; Toxicology -- Periodicals; Toxicologie -- Périodiques; Intoxications alimentaires -- Périodiques; Food poisoning; Toxicology; Periodicals; Electronic journals; 615.9
• DOI: 10.1016/j.fct.2015.08.010
• Languages: English
• ISSNs: 0278-6915

Abstract

Abstract: This study aimed to investigate the degradation of three transgenic Bacillus thuringiensis (Bt) genes ( Cry1Ab, Cry1Ac, and Cry1Ab/Ac ) and the corresponding encoded Bt proteins in KMD1, KF6, and TT51-1 rice powder, respectively, following autoclaving, cooking, baking, or microwaving. Exogenous Bt genes were more stable than the endogenous sucrose phosphate synthase ( SPS ) gene, and short DNA fragments were detected more frequently than long DNA fragments in both the Bt and SPS genes. Autoclaving, cooking (boiling in water, 30 min), and baking (200 °C, 30 min) induced the most severe Bt protein degradation effects, and Cry1Ab protein was more stable than Cry1Ac and Cry1Ab/Ac protein, which was further confirmed by baking samples at 180 °C for different periods of time. Microwaving induced mild degradation of the Bt and SPS genes, and Bt proteins, whereas baking (180 °C, 15 min), cooking and autoclaving led to further degradation, and baking (200 °C, 30 min) induced the most severe degradation. The findings of the study indicated that degradation of the Bt genes and proteins somewhat correlated with the treatment intensity. Polymerase chain reaction, enzyme-linked immunosorbent assay, and lateral flow tests were used to detect the corresponding transgenic components. Strategies for detecting transgenic ingredients in highly processed foods are discussed. Highlights: The Bt gene is relatively more stable than the SPS gene under thermal treatment. For Bt gene or SPS gene short DNA fragments are more stable than long DNA fragments. The degradation of Bt gene and protein were positively correlated with the treatment violence. The protein of Cry1Ab is more stable than protein of Cry1Ac and Cry1Ab/Ac.