Transgenic Camelina Sativa As A Source Of Oils To Replace Marine Fish Oil In Aquaculture Feeds

摘要

Marine fish oils are a finite and limited resource and the use of high levels in aquafeeds is a non-sustainable practice (Tocher, 2015). Alternative oils sourced from terrestrial plants do not contain omega-3 long-chain polyunsaturated fatty acids (LC-PUFA), therefore, feeds based on conventional vegetable oils reduce levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in farmed fish (Turchini etal., 2010). Consequently, the aquaculture industry requires new oil sources that containhigh levels of omega-3 LC-PUFA to supply the increasing demand for fish and seafood while maintaining the high nutritional quality of farmed products. One viable approach to the renewable supply of omega-3 LC-PUFA is metabolic engineering oilseed crops with the capacity to synthesize these critical fatty acids (Sayanova and Napier, 2011). Recently, the oilseed Camelina sativa has been transformed with algal genes encoding the omega-3 biosynthetic pathway and expression restricted to the seeds via seed-specific promoters to produce oils containing either EPA alone or EPA and DHA (Ruiz-Lopez et al., 2014). These oils were investigated as replacements for marine fish oil in feeds for Atlantic salmon (Salmo salar) and gilthead sea bream (Sparus aurata). Inaddition to assessing the ability of these novel oils to maintain the nutritional quality of farmed fish, these studies have contributed to our understanding of the biochemical and molecular mechanisms involved in the control and regulation of DHA production from EPA, and thus better inform our understanding of the LC-PUFA biosynthetic pathway in salmonids and marine fish species.