The supply of fish oil to aquaculture: a role for transgenic oilseed crops?

Abstract

The importance of an alternative and sustainable supply of omega-3 long chain polyunsaturated fatty acids (LC omega-3) has long been established. As these biologically active fatty acids have a role in nutrition and health, there is an ever increasing demand for oils containing LC omega-3 e.g. eicosapentaenoic (EPA) and docosahexaenoic acid (DHA). These fatty acids are produced by micoroganisms and enter our diet through the consumption of fish. However, in order that the nutritional requirements of fish in aquaculture are met and sufficient levels are deposited to meet the requirements of human consumers, EPA and DHA must be supplied in excess. Given the importance of the aquaculture industry in delivering healthy foodstuff, the question of how to resource the supply of LC omega-3 then arises; traditional sources of EPA and DHA (fish oil) are challenged, whilst vegetable oils do not contain EPA or DHA. Therefore research efforts have focused on the successful reconstitution of LC omega-3 biosynthesis in oilseed crops. The production of EPA and DHA in the seed oil of agricultural crops has the capacity to deliver large volumes of these fatty acids. The expression of optimised combinations of the genes required to produce these fatty acids in the seed of the crop Camelina sativa has been achieved and the utility of this approach demonstrated. This represents a significant breakthrough – the provision of an effective alternative to the use of omega-3 fish oil by the global aquaculture industry.