<P> In materials science, a genetically modified virus has been used in a research laboratory as a scaffold for assembling a more environmentally friendly lithium - ion battery . Bacteria have also been engineered to function as sensors by expressing a fluorescent protein under certain environmental conditions . </P> <P> One of the best - known and controversial applications of genetic engineering is the creation and use of genetically modified crops or genetically modified livestock to produce genetically modified food . Crops have been developed to increase production, increase tolerance to abiotic stresses, alter the composition of the food, or to produce novel products . </P> <P> The first crops to be realised commercially on a large scale provided protection from insect pests or tolerance to herbicides . Fungal and virus resistant crops have also being developed or are in development . This make the insect and weed management of crops easier and can indirectly increase crop yield . GM crops that directly improve yield by accelerating growth or making the plant more hardy (by improving salt, cold or drought tolerance) are also under development . In 2016 Salmon have been genetically modified with growth hormones to reach normal adult size much faster . </P> <P> GMOs have been developed that modify the quality of produce by increasing the nutritional value or providing more industrially useful qualities or quantities . The Amflora potato produces a more industrially useful blend of starches . Soybeans and canola have been genetically modified to produce more healthy oils . The first commercialised GM food was a tomato that had delayed ripening, increasing its shelf life . </P>

Genetic engineering is employed in the production of