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GM starch potatoes as a renewable raw material

Amflora - a potato for industrial applications.

A GM potato with a modified starch composition that makes it more suitable for certain industrial applications has been authorised for cultivation in Europe since March 2010. The potato was developed by BASF Plant Science and was subjected to repeated scientific analyses and tests during an approval process that lasted 13 years, before being approved by the European Commission in 2010. At the beginning of 2012, however, BASF stopped marketing the Amflora potato in Europe because of a lack of public acceptance.

The starch in a conventional potato consists of two components - amylopectin and amylose. Both these components are of equal value in terms of human nutrition. However, in industrial processes they cannot be used together because they have different characteristics: usually, only the thickening properties of amylopectin are required, while the gelling amylose component is undesirable in many products and can interfere with certain processes. The chemical modification or separation of these two components is associated with increased consumption of energy and water.

Industrial raw material. The Amflora potato is intended exclusively as raw material for the starch industry. In addition, recycling of the waste material from the starch production as animal feed has been permitted.

Starch grains under the microscope: the starch grains in the potato tubers turn blue in an iodine solution if they contain amylose as well as amylopectin

Amylopectin starch.
When amylose is no longer produced, because the gene for the starch synthase enzyme has been switched off, the starch grains turn red
Photos: MPIZ Cologne

Potato flowers. Outcrossing is not a problem with potatoes. However, farmers who want to grow the Amflora potato still have to adhere to certain regulations.

Antisense strategy: blocking enzyme synthesis

Researchers at BASF Plant Science have now developed a new starch potato (under the brand name Amflora), which produces starch composed almost exclusively of amylopectin. Using the antisense strategy, they switched off the gene for the starch synthase enzyme, which is involved in the synthesis of amylose, by inserting a mirror image of the gene (‘antisense’) into the DNA of the potato. This blocks the information to synthesise the enzyme.

Field testing for environmental safety

The genetically modified amylopectin potato has already undergone several years of field trials to test yields, pest and disease resistance, and also to determine whether it is harmful to human and animal health or the environment. The field trials took place in the Czech Republic, the Netherlands and Sweden. Since 2006, Amflora has been tested at different locations, also in Germany, in some on a large scale.

Approval: Conflict of basic principles concerning green gene technology

The first applications for approval for the newly developed potato were submitted already in 1996. In 2003, after the approval moratorium expired in the EU, a new application for the Amflora potato was filed for cutlivation, and two years later its utilisation as food and feed stuff. For the safety appraisal and approval process it was decisive that the new significantly tightened EU regulations for gene technology were then in force.

However, politically there was more than one single approval application at stake. The Amflora potato would be the first genetically modified plant that had received approval in the EU since 1998. It had become a symbolic, charged issue, in which a political conflict of basic principles about green gene technology was being carried out.

After the expert panel responsible for gene technology in European food safety had assessed the Amflora potato as being safe for the environment as well as for the health of both people and animals, the start for commercial cultivation was expected in 2007.

Since the Member States could not agree with the necessary relative majority on either acceptance or rejection of the Amflora potato, according to EU law it fell to the EU commission to make the decision. However, in contrast to similar cases, the Commission hesitated.

The concerns of the then Environment Commissar Stavros Dimas, as well as many gene technology-critical organisations focussed in particular on the “Amflora” genetic marker that mediates an antibiotic resistance against kanamycin.

The European Medicines Agency (EMEA) confirms that antibiotics in the kanamycin group play an important role in treating certain infectious diseases in human and animal medicine. However, in a further report in June 2009, EFSA’s GMO Panel declared Amflora to be harmless in this regard. The GMO Panel considers gene transfer from a GM plant to bacteria to be highly unlikely. The effectiveness of antibiotics would therefore not be compromised.

Marketing stopped after two years

At the beginning of March 2010, after more than a decade in the system, the Amflora potato was finally approved by the European Commission. Although the Amflora potato is conceived exclusively as a raw material for the starch industry, approval was also sought for food and feed applications. The idea was that some of the by-products would be used for animal feed. The application for approval for use in food was filed as a precaution, in case some of the GM potatoes ended up in the food-processing chain by mistake. As with all GM plants that are approved in the EU and which have therefore been assessed as safe, adventitious, technically unavoidable levels of up to 0.9 per cent are permitted.

Cultivation of the Amflora potato began in 2010 on a small scale in the Czech Republic (150 ha), Sweden (80 ha) and Germany (15 ha). In Germany, the plan was to grow seed potatoes for the following years, although this plan was accompanied by protests and disruptive action. In 2011, Amflora potatoes were grown on only two hectares in Germany.

In January 2012, BASF stopped marketing the Amflora potato in Europe and relocated the headquarters of BASF Plant Science from Germany to the USA.