EFSA confirms GM antibiotic-related gene safety
The consolidated overview, including a joint scientific opinion of the GMO and BIOHAZ Panels, looked at the use of antibiotic resistance marker genes (ARMG) in GM plants, most notably BASF’s Amflora potato.
“Two minority opinions were expressed and extensively considered during the preparation of the joint opinion and no further clarification or scientific work were needed at this time,” said EFSA’s website.
“In their joint opinion, the GMO and BIOHAZ Panels concluded that transfers of ARMG from GM plants to bacteria have not been shown to occur either in natural conditions or in the laboratory. The key barrier to stable uptake of antibiotic resistance marker genes from GM plants to bacteria is the lack of DNA sequence identity between plants and bacteria.”
The German biotech giant welcomed the opinion. Dr. Stefan Marcinowski, Member of the Board of Executive Directors of BASF said: “Today’s assessment gives the entire EU Commission the final scientific clarity to approve Amflora. I am pleased, since the EU Commission stated in May 2008 that it will approve Amflora ‘if and when’ EFSA has confirmed the safety of the product.”
Inspired by starch
According to BASF, the idea of developing Amflora originated in the European starch industry. Europe is already a significant producer of potato starch. Normal potato starch is valued for its high molecular weight (giving excellent thickening properties) and low levels of fat and protein compared to wheat and cornstarch.
Nearly all starches have two components - a high molecular weight, highly branched molecule with excellent thickening properties, called amylopectin, and a smaller, linear molecule which gels, called amylose.
The 20 per cent amylose in normal potato starch limits its usefulness for many industrial applications. Separation of the two components is not economic, so most industrial starch is first chemically modified to reduce the gelling tendency.
But through genetic modification, BASF Plant Science developed a nearly 100 per cent amylopectin starch.
This was achieved by tweaking the pathway by which it is made in the plant cells. Both amylopectin and amylose are built from the same simple sugar dextrose and the different physical properties come about because of the way the monomers are joined.
The linear chains of amylose are constructed using a single enzyme called GBSS (Granule Bound Starch Synthase). Scientists have used biotechnology to make a back-to-front copy of the gene (called an anti-sense gene) and then inserted this into the DNA of a conventional potato using a bacterium (Agrobacterium tumefaciens).
The anti-sense gene interferes with the operation of the normal gene, and no GBSS is produced. In the absence of this enzyme, the polymerisation of dextrose all goes in one direction, to produce amylopectin.
The starch is used predominantly for technical purposes, such as paper making, while the rest of the potato (pulp) is intended for animal feed, said a company spokesperson.
The nptII gene is also used in maize MON 863 and hybrids, said EFSA.