Ubiquitous Promoters Direct the Expression of Fatty Acid Delta-6 Desaturase from Nile Tilapia (Oreochromis niloticus) in Saccharomyces cerevisiae

In general, promoters have significant influence on recombinant protein production. Herein, we compared the performance of actin (pACT), phosphoglycerate kinase (pPGK), and translational elongation factor (pTEF) promoters for driving the expression of fatty acid delta-6 (Δ6) desaturase from Nile tilapia (Oreochromis niloticus; Oni-fads2) in Saccharomyces cerevisiae. Our results showed that by applying real-time RT-PCR, the highest level of Oni-fads2 mRNA was observed in S. cerevisiae carrying the expression vector driven by pTEF promoters. Exogenous substrate C18:2n-6 was used to determine Δ6 activity by quantitatively determining the C18:3n-6 product. The results showed that highest Δ6 desaturation was observed when using pTEF as a promoter. Recombinant S. cerevisiae cells expressing Oni-fads2 driven by pTEF were tested with the substrate C18:3n-3, and Δ6 desaturation efficiently converted C18:3n-3 to C18:4n-3. Furthermore, crude extract of recombinant yeast also exhibited Δ6 activity. Thus, recombinant S. cerevisiae cells expressing Oni-fads2 driven by the pTEF promoter have potential as a yeast factory for the sustainable production of long-chain polyunsaturated fatty acids.

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Effect of lipid feeding regimes and conditioning periods on gonads fatty acid profile and reproductive performance of the Nile tilapia (Oreochromis niloticus) broodstock

Egyptian Journal of Aquatic Biology and Fisheries ◽

10.21608/ejabf.2018.8766 ◽

2018 ◽

Vol 22 (3) ◽

pp. 25-36

Author(s):

Osama M. El-Husseiny ◽

Ashraf M. A. Goda ◽

Rania S. Mabroke ◽

Ali Matter

Keyword(s):

Fatty Acid ◽

Fatty Acid Profile ◽

Reproductive Performance ◽

Oreochromis Niloticus ◽

Nile Tilapia ◽

Nile Tilapia Oreochromis Niloticus ◽

Feeding Regimes

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Identification and quantification of dicarboxylic fatty acids in head tissue of farmed Nile tilapia (Oreochromis niloticus)

European Food Research and Technology ◽

10.1007/s00217-021-03747-5 ◽

2021 ◽

Author(s):

Katja Lehnert ◽

Mamun M. Rashid ◽

Benoy Kumar Barman ◽

Walter Vetter

Keyword(s):

Fatty Acids ◽

Fatty Acid ◽

Linoleic Acid ◽

Low Income ◽

Oreochromis Niloticus ◽

Nile Tilapia ◽

Daily Intake ◽

Acid Methyl Ester ◽

Human Consumption ◽

The European Union

AbstractNile tilapia (Oreochromis niloticus) was grown in Bangladesh with four different feeding treatments as part of a project that aims to produce fish in a cost-effective way for low-income consumers in developing countries. Fillet and head tissue was analysed because both tissues were destined for human consumption. Gas chromatography with mass spectrometry (GC/MS) analyses of transesterified fatty acid methyl ester extracts indicated the presence of ~ 50 fatty acids. Major fatty acids in fillet and head tissue were palmitic acid and oleic acid. Both linoleic acid and polyunsaturated fatty acids with three or more double bonds were presented in quantities > 10% of total fatty acids in fillet, but lower in head tissue. Erucic acid levels were below the newly proposed tolerable daily intake in the European Union, based on the consumption of 200 g fillet per day. Moreover, further analysis produced evidence for the presence of the dicarboxylic fatty acid azelaic acid (nonanedioic acid, Di9:0) in head tissue. To verify this uncommon finding, countercurrent chromatography was used to isolate Di9:0 and other dicarboxylic acids from a technical standard followed by its quantification. Di9:0 contributed to 0.4–1.3% of the fatty acid profile in head tissue, but was not detected in fillet. Fish fed with increasing quantities of flaxseed indicated that linoleic acid was the likely precursor of Di9:0 in the head tissue samples.

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