Effect of short- and long-term lipid enrichment on total lipids, lipid class and fatty acid composition in rotifers

✍ Scribed by Jose R. Rainuzzo; Kjell I. Reitan; Yngvar Olsen

• Publisher: Springer Netherlands
• Year: 1994
• Tongue: English
• Weight: 816 KB
• Volume: 2
• Category: Article
• ISSN: 0967-6120
• DOI: 10.1007/bf00118530

✦ Synopsis

Four emulsions differing in lipid class composition: triacylglycerols, ethyl esters, phospholipids and wax esters were used to enrich rotifers either through short-term (ST) enrichment (24 h) or through long-term (LT) enrichment (10 days). Higher lipid levels were obtained by using the ST enrichment method. This was particularly marked in the high triacylglycerol accumulation in rotifers enriched on the phospholipid-based emulsion. Ethyl esters were effectively assimilated and incorporated into triacylglycerol by rotifers in both the ST and LT techniques. A high docosaehexanoic/eicosapentaenoic acid (DHA/EPA) ratio was obtained in the LT technique using the ethyl ester-based emulsion. However, the other emulsion treatments gave higher or equal DHA/ EPA ratios using the ST technique. Absolute phospholipid levels were independent of both dietary lipid composition and enrichment method used, whereas triacylglycerol levels depended on these parameters. During starvation the level of phospholipid, in absolute terms, decreased slightly whereas the triacylglycerol fraction decreased considerably. Rotifers enriched on the wax esterbased emulsion using the LT technique exhibited higher levels of long-chain monoenes (i.e. 20:1 and 22:1 isomers) than when the ST technique was used. This suggests that hydrolysis of the wax esters and oxidation of the liberated fatty alcohols to fatty acids occurred when the LT technique was applied.