Original Research ARTICLE
Lack of Detection of Bt Sugarcane Cry1Ab and NptII DNA and Proteins in Sugarcane Processing Products including Raw Sugar
- 1Regulatory Department, Sugarcane Research Center (Brazil), Brazil
- 2Biotechnology Department, Sugarcane Research Center (Brazil), Brazil
- 3Ron Lirette Biotech Consulting LLC, United States
Brazil is the largest sugarcane producer and the main sugar exporter in the world. The industrial processes applied by Brazilian mills are very efficient in producing highly purified sugar and ethanol. Literature presents evidence of lack of DNA/protein in these products, regardless of the nature of sugarcane used as raw material. Recently CTNBio, the Brazilian biosafety authority, has approved the first biotechnology-derived sugarcane variety for cultivation, event CTC175-A, which expresses the Cry1Ab protein to control the sugarcane borer (Diatraea saccharalis). The event also expresses NptII (neomycin-phosphotransferase type II) protein used as selectable marker during the transformation process. Because of the high purity of sugar and ethanol produced from genetically modified sugarcane, these end-products should potentially be classified as “pure substances, chemically defined”, by Brazilian Biosafety Law N° 11.105. If this classification is to be adopted, these substances are not considered as “GMO derivatives” and fall out of the scope of Law N° 11.105. In order to assess sugar composition and quality, we evaluate Cry1Ab and NptII expression in several sugarcane tissues and in several fractions from laboratory-scale processing of event CTC175-A for the presence of these heterologous proteins as well as for the presence of traces of recombinant DNA. The results of these studies show that CTC175-A presents high expression of Cry1Ab in leaves and barely detectable expression of heterologous proteins in stalks. We also evaluated the presence of RuBisCO protein and DNA in the fractions of the industrial processing of conventional Brazilian sugarcane cultivars. Results from both laboratory and industrial processing were concordant, demonstrating that DNA and protein are not detected in the clarified juice and downstream processed fractions, including ethanol and raw sugar, indicating that protein and DNA are removed and/or degraded during processing. In conclusion, the processing of conventional sugarcane and CTC175-A Bt event results in downstream products with no detectable concentrations of heterologous DNA or newly-expressed protein. These results help in the classification of sugar and ethanol derived from CTC175-A event as pure, chemically defined substances in Brazil and may relieve regulatory burdens in countries that import Brazilian sugar.
Keywords: sugar, Highly purified substance, Saccharum, Cry1Ab, nptII
Received: 11 Dec 2017;
Accepted: 28 Feb 2018.
Edited by:Reynaldo A. Alvarez Morales, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Mexico
Reviewed by:Robert Winkler, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Mexico
Wayne Parrott, University of Georgia, United States
Copyright: © 2018 Cheavegatti Gianotto, Gentile, Oldemburgo, Merheb, Sereno, Lirette, Ferreira and de Oliveira. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: PhD. Adriana Cheavegatti Gianotto, Sugarcane Research Center (Brazil), Regulatory Department, Fazenda Santo Antonio s/n, Mailbox 162, Piracicaba, 13400-970, São Paulo, Brazil, firstname.lastname@example.org