Linoleic Acid Precursors Research Articles

Engineering Yarrowia lipolytica for Sustainable Production of the Pomegranate Seed Oil-Derived Punicic Acid.

Punicic acid is a conjugated linolenic acid with various biological activities including antiobesity, antioxidant, anticancer, and anti-inflammatory effects. It is often used as a nutraceutical, dietary additive, and animal feed. Currently, punicic acid is primarily extracted from pomegranate seed oil, but it is restricted due to the extended growth cycle, climatic limitations, and low recovery level. There have also been reports on the chemical synthesis of punicic acid, but it resulted in a mixture of structurally similar isomers, requiring additional purification/separation steps. In this study, a comprehensive strategy for the production of punicic acid in Yarrowia lipolytica was implemented by pushing the supply of linoleic acid precursors in a high-oleic oil strain, expressing multiple copies of the fatty acid conjugase gene from Punica granatum, engineering the acyl-editing pathway to improve the phosphatidylcholine pool, and promoting the assembly of punicic acid in the form of triglycerides. The optimal strain with high oil production capacity and a significantly increased punicic acid ratio accumulated 3072.72 mg/L punicic acid, accounting for 6.19% of total fatty acids in fed-batch fermentation, providing a viable, sustainable, and green approach for punicic acid production to substitute plant extraction and chemical synthesis production.

Effects of low salinities on growth, fatty acid composition, and transcriptome in Florida pompano (Trachinotus carolinus) at early developmental stages

The Florida pompano, Trachinotus carolinus, is a prime marine finfish candidate for commercial production in the United States (U.S.). Low salinity conditions (i.e., < 30 parts per thousand, ppt) can affect the early development of T. carolinus by increasing osmoregulatory stress. To address the knowledge gap regarding the impact of low salinity on Florida pompano health, we conducted an experiment to determine the optimal salinity for the culture of fingerlings. Larvae were reared in three salinities (10, 20, and 30 ppt) at local producers' farms and growth, fatty acid profiles, and transcriptome responses were quantified every three days after hatching (3, 6, 9, 12, 15, 18, and 24 days post hatch) and results were compared across salinities. Larvae reared at 10 ppt grew at a normal rate and the developmental stage had a greater impact than salinity on fatty acid composition and larval gene expression. Although there were few differentially expressed genes between salinities (n = 17), there was an upregulation of gene sets associated with ribosomes and oxidative phosphorylation and a downregulation of glycerophospholipid and carbon metabolism at lower salinities in comparison to higher salinities. In the early days of development, the fatty acids linoleic acid (LA), alpha linoleic acid (LNA), and 18:3 n-6 were proven to be important as potential energy fuels and precursors for long-chain polyunsaturated fatty acids (LC-PUFA) biosynthesis, which was supported by the whole transcriptomics analysis. The gene expression of fatty acid synthesis genes coincided with changes in the fatty acid levels suggesting the ability of Florida pompano larvae to biosynthesize LC-PUFAs from LA and LNA precursors. Overall, this study suggests that it is possible to raise Florida pompano larvae for 24 DPH under low salinity conditions as low as 10 ppt. However, it is important to run this study for a longer period to investigate the long-term effects of low salinity on larval health and development. Importantly, this research serves as a model study for future on-farm collaborations and helps build a bridge between scientists and farmers in aquaculture.

Effect of Media Components and Growth Conditions for Improved Linoleic Acid Production by Beauveria Species

AbstractBeauveria species are well‐known insect pathogenic fungi, and Beauveria bassiana is used as a biopesticide against various pests in agriculture. However, the Beauveria species has not been reported as producers of microbial oils. In this study, Beauveria spp. MTCC 5184 was used to produce microbial oil with high linoleic acid (LA) content. Ten experiments were performed to evaluate the effects of several media parameters, such as carbon and nitrogen sources, pH, various concentrations of carbon and nitrogen, growth duration, and oleic acid (OLA) supplementation for maximum LA and dry biomass production by the fungus. Several of these parameters had a significant impact on the production of LA, as well as dry biomass. The glucose yeast extract (GYE) medium supplemented with 1.5% (w/v) peptone yielded maximum LA (0.32 ± 0.01 g L−1) and biomass (5.51 ± 0.26 g L−1). However, through the addition of 1.0% (w/v) OLA, the precursor of LA, LA production was enhanced 12‐fold (1.24 ± 0.03 g L−1), and the biomass production increased by 5‐fold (11.05 ± 0.46 g L−1) in comparison to those in the basal (GYE) medium. Using lactose as the sole carbon source produced the lowest LA (0.05 ± 0.00 g L−1) and biomass (1.04 ± 0.10 g L−1). The results of this study will be useful for the commercial exploitation of this fungus for the production of LA‐rich microbial oil for use in the production of lubricants, greases, paints, cosmetics, etc.

Phytochemicals from nine plants beneficial for pregnant women

The phytochemicals found in nine plants which are easily accessible to the women living in developing countries in particular is studied as the prevalence of diseases caused by lack of prenatal nutrients is high in these countries. Knowledge about these plants would help the expectant women to get the maximum prenatal nutrients like Folic acid, Iron, Vitamin B6, Zinc, Calcium, Choline and Alpha linoleic acid precursors needed to synthesize Omega 3 fats which are vital for the foetal growth and development. These plants are easily available and are affordable to the majority of poor women living in slums of the city dwellers and those who live in villages. Due to lack of knowledge, money, palatability issues, improper storage and consumption irregularities the expectant mothers in this category do not consume prescribed prenatal nutrients, affecting the mother and the foetus. Though prescribed prenatal nutrients are still very essential, same from the food sources have many benefits like they are from the complex mixture of many phytochemicals which act synergistically and provide known and unknown benefits to them. Apart from this, most of the plants listed here can be easily grown in pots or plots near their homes, manuring with kitchen wastes and without using chemical fertilizers or pesticides. Plants that provide all the prenatal nutrients and easily accessible for daily consumption by the pregnant women at an affordable cost in developing countries are Cowpea, Tomatoes, Turnip greens, Garlic, Wheat, Drumstick leaves, Cauliflower, purslane and Guava fruits.

Oleic acid is a precursor of linoleic acid and the male sex pheromone in Nasonia vitripennis

Linoleic acid (C18:2Δ9,12, LA) is crucial for many cell functions in organisms. It has long been a paradigm that animals are unable to synthesize LA from oleic acid (C18:1Δ9, OA) because they were thought to miss Δ12-desaturases for inserting a double bound at the Δ12-position. Today it is clear that this is not true for all animals because some insects and other invertebrates have been demonstrated to synthesize LA. However, the ability to synthesize LA is known in only five insect orders and no examples have been reported so far in the Hymenoptera. LA plays a particular role in the parasitic wasp Nasonia vitripennis, because it is the precursor of the male sex pheromone consisting of (4R,5R)- and (4R,5S)-5-hydroxy-4-decanolides. Here we demonstrate by stable isotope labeling that N. vitripennis is able to incorporate externally applied fully 13C-labeled OA into the male sex pheromone suggesting that they convert initially OA into LA. To verify this assumption, we produced fly hosts (Lucilia caesar) which were experimentally enriched in 13C-labeled OA and reared male parasitoids on these hosts. Chemical analysis of transesterified lipid raw extracts from hosts and parasitoids revealed that N. vitripennis but not L. caesar contained 13C-labeled LA methyl ester. Furthermore, male wasps from the manipulated hosts produced significant amounts of 13C-labeled sex pheromone. These results suggest that N. vitripennis possesses a Δ12-desaturase. The additional fitness relevant function as pheromone precursor might have favored the evolution of LA biosynthesis in N. vitripennis to make the wasps independent of the formerly essential nutrient.

A novel FAD2-1 A allele in a soybean plant introduction offers an alternate means to produce soybean seed oil with 85% oleic acid content

The alteration of fatty acid profiles in soybean to improve soybean oil quality has been a long-time goal of soybean researchers. Soybean oil with elevated oleic acid is desirable because this monounsaturated fatty acid improves the nutrition and oxidative stability of soybean oil compared to other oils. In the lipid biosynthetic pathway, the enzyme fatty acid desaturase 2 (FAD2) is responsible for the conversion of oleic acid precursors to linoleic acid precursors in developing soybean seeds. Two genes encoding FAD2-1A and FAD2-1B were identified to be expressed specifically in seeds during embryogenesis and have been considered to hold an important role in controlling the seed oleic acid content. A total of 22 soybean plant introduction (PI) lines identified to have an elevated oleic acid content were characterized for sequence mutations in the FAD 2-1A and FAD2-1B genes. PI 603452 was found to contain a deletion of a nucleotide in the second exon of FAD2-1A. These important SNPs were used in developing molecular marker genotyping assays. The assays appear to be a reliable and accurate tool to identify the FAD 2-1A and FAD2-1B genotype of wild-type and mutant plants. PI 603452 was subsequently crossed with PI 283327, a soybean line that has a mutation in FAD2-1B. Interestingly, soybean lines carrying both homozygous insertion/deletion mutation (indel) FAD2-1A alleles and mutant FAD2-1B alleles have an average of 82-86% oleic acid content, compared to 20% in conventional soybean, and low levels of linoleic and linolenic acids. The newly identified indel mutation in the FAD2-1A gene offers a simple method for the development of high oleic acid commercial soybean varieties.

Visual membranes: specificity of fatty acid precursors for the electrical response to illumination.

Rat electroretinograms were measured as a function of dietary supplements of purified ethyl esters of linolenic acid, linoleic acid, and oleic acid. Polyunsaturated fatty acids derived from precursors of linolenic and linoleic acids appear to be important functional components of photoreceptor cell membranes, although in equal dietary concentrations, linolenic acid precursors affect electroretinogram amplitudes to a greater extent than linoleic acid precursors. The electrical response of photoreceptor cell membranes appears to be a function of the position of the double bonds as well as a function of the total number of double bonds in fatty acid supplements.

THE BIOSYNTHESIS OF RICINOLEIC ACID.

1. Ricinoleic acid is shown to be synthesized in the immature castor bean seed only after 3-4 weeks from the time of fertilization. 2. Synthesis occurs both in the isolated embryo and the endosperm. 3. Linoleic acid does not act as precursor of ricinoleic acid in the isolated bean embryo. 4. Oleic acid is shown to be the direct precursor of ricinoleic acid. 5. The reaction does not use molecular oxygen. This suggests that ricinoleic acid is not a precursor of linoleic acid.

Influence of Dietary Medium-Chain Fatty Acids on Rat Lipid Composition: I. cis-2-Octenoic Acid as Precursor of Linoleic Acid

Influence of Dietary Medium-Chain Fatty Acids on Rat Lipid Composition: I. cis-2-Octenoic Acid as Precursor of Linoleic Acid