Breeding Aims Production of Pharmaceuticals, Enzymes and 'Bio' Raw Materials

The world's plants are capable of producing an enormous spectrum of useful substances. With genetic engineering, the potential also exists to modify plants to efficiently produce valuable pharmaceuticals, biodegradable materials for industry, or enzymes that can improve animal feed. This technology is sometimes known as molecular farming or biopharming.

If such plants ever make it to open fields, extreme care would have to be taken to ensure that the novel gene responsible for producing the active substance does not accidently spread to the environment or to the food supply. Scientists will need to use containment strategies to prevent  the out-crossing of transgenes. Such concepts are described in the chapter "environmental safety".

Industrial applications: "Bio" plastic

Transgenic plants can be used to produce biodegradable plastics such as polyhydroxybutyrate (PHB). Researchers have taken two genes from the bacterium Alcaligenes eutrophus, which encode enzymes responsible for synthesising the naturally occurring plastic PHB, and introduced them into plants. PHBs are 100% biodegradable and are physically similar to polyethylene.

PHB and other related plastics are already produced commercially by bacterial fermentation. Known commercially as BiopolTM, they have a wide range of uses from medical implants to shopping bags.

Improved animal feed

Phosphorous overabundance in poultry manure is a common environmental problem in areas of intensive livestock production. When added to animal feed, the enzyme phytase can alleviate this problem by reducing phosphorus discharge by up to a third. Scientists have genetically modified the forage crop alfalfa to contain high levels of phytase.

'Quality traits'

Some of these new “quality traits” are already in use in the US, while others are well advanced in development. For the time being, no approval applications for GM plants for producing specialty substances have been submitted in the EU. However, the EU produces many important enzymes with the help of genetically modified microorganisms.