Microbial and genetically engineered oils as replacements for fish oil in aquaculture feeds

Abstract

As the global population grows more of our fish and seafood are being farmed. Fish are the main dietary source of the omega-3 (n-3) long-chain polyunsaturated fatty acids (LC-PUFA), eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids, but these cannot be produced in sufficient quantities as are now required for human health. Farmed fish have traditionally been fed a diet consisting of fishmeal and fish oil, rich in n-3 LC-PUFA. However, the increase in global aquaculture production has resulted in these finite and limited marine ingredients being replaced with sustainable alternatives of terrestrial origin that are devoid of n-3 LC-PUFA. Consequently, the nutritional value of the final product has been partially compromised with EPA and DHA levels both falling. Recent calls from the salmon industry for new sources of n-3 LC-PUFA have received significant commercial interest. Thus, this review explores the technologies being applied to produce de novo n-3 LC-PUFA sources, namely microalgae and genetically engineered oilseed crops, and how they may be used in aquafeeds to ensure that farmed fish remain a healthy component of the human diet.

The Potential for ‘Next-Generation’, Microalgae-Based Feed Ingredients for Salmonid Aquaculture in Context of the Blue Revolution

“…As such, they are now cultivated heterotrophically in the absence of light in large-scale fermentation systems using organic carbon sources for industrial production of food-grade DHA and are available commercially in various processed forms (e.g., whole-cell lipid-rich powders, extracted oil emulsions, etc.). The aquaculture feed market is in desperate need of these DHA-rich oils as the Global Salmon Initiative (GSI) has indicated that its members could immediately take up 200,000 t annually of this novel alternative lipid source if it were available [6].…”

The composition and oxidative stability of vegetarian omega‐3 algal oil nanoemulsions suitable for functional food enrichment

“…The European Food Safety Agency have approved health claims in relation to foods naturally rich or fortified with EPA and DHA. Microalgal oils have recently emerged to offer a sustainable alternative source of EPA and DHA that is also suitable for vegetarians and vegans …”

“…Microalgal oils have recently emerged to offer a sustainable alternative source of EPA and DHA that is also suitable for vegetarians and vegans. [9][10][11] Nanoemulsions, similar to conventional oil-in-water emulsion systems but with considerably smaller droplet sizes, can be used to incorporate lipid-based components into aqueous foods. 12 The use of nanoemulsions offers potential benefits, including increases in water dispersibility of oils, good physical and chemical stability, and improved bioavailability of various hydrophobic lipid components.…”

Dietary Polyunsaturated Fatty Acid Supplementations Could Significantly Promote the Δ6 Fatty Acid Desaturase and Fatty Acid Elongase Gene Expression, Long Chain Polyunsaturated Fatty Acids, and Growth of Juvenile Cobia

“…Most of marine fish have to ingest LC‐PUFA from their diets since their fatty acid desaturases and/or ELOVL5 are not efficient enough to produce LC‐PUFA from the SC‐PUFA, which are different from freshwater fish . Fish oil is rich in LC‐PUFA and the main source of LC‐PUFA of humans and other animals . However, the source of fish oil is limited with the rapid development of marine aquaculture .…”

“…Fish oil is rich in LC‐PUFA and the main source of LC‐PUFA of humans and other animals . However, the source of fish oil is limited with the rapid development of marine aquaculture . Fish oil has to be substituted for aquaculture and plant oil is a good substitute of fish oil .…”