Development and evaluation of peroxide free fin-fish nursery feeds with active DHA-synthase enzyme (DSe)

The marine microalgae Crypthecodinium cohnii (C. cohnii) contains high levels of DHA and DHA synthase enzyme (DSe) both of which may provide nutritional benefits to finfish for human consumption. Field Phyto-Nutrients LLC has developed a process for algae-based feed preparation where the algae is dried under low temperature (<40ºC) and under an atmosphere of inert gas to prevent lipid peroxidation and denaturation of enzymes. The process results in flakes and/or powder products called KoniSap (KS) aimed to supplement aquafeeds. KS can also be fed to zooplankton such as Artemia to be used as an enriched live feed. In a preliminary trial, salmon fry fed commercial starter feeds supplemented by KS exhibited higher DHA concentrations in fish tissues when compared to control groups. The observed differences may be attributed to the enhanced DHA as well as potential activity of DSe. The proposed trials will evaluate the use and effects of KS as a supplemental flake feed for steelhead trout (Oncorhynchus mykiss) and as an Artemia enrichment for marine fish larvae (inland silversides; Menidia beryllina). An intentionally denatured KS flake is proposed as a negative control to evaluate DSe as a potential pathway for DHA production.