Production Of Omega-3 Fatty Acids Research Articles

Protective effects of flaxseed oil against dexamethasone induced skeletal muscle atrophy on rats

The production of omega-3 fatty acids in the lipids of muscle tissue was boosted by flaxseed oil (Linum usitatissimum), which is well-described in the Ayurvedic system of medicine. In skeletal muscle disorders, atrophy is a major problem which arises due to cachexia, sarcopenia and immobilization. Nevertheless, despite significant efforts, few FDA-approved medications are available in the market to treat skeletal muscle atrophy. The current project was conceptualized to investigate the protective effects of flaxseed oil against dexamethasone-induced muscular atrophy in adult Sprague Dawley Rats. Marketed preparation of dexamethasone was used to induce muscle atrophy and flaxseed oil was administered orally after disease induction of 7 days till 28 days. Body weight and behavioural studies were carried out to assess muscle mass and glucose. Due to its high antioxidant and fatty acid Omega-3 content, flaxseed oil promotes significant improvements in diseased animals. Rats administered with flaxseed oil demonstrated great weight gain and a decreased blood sugar level. After three weeks-blood sugar levels, muscle mass, momentary changes in rats and HDL levels were all significantly higher in the dexamethasone alone treated control group animals. Flaxseed oil protects against the biochemical and histopathological changes caused due to dexamethasone toxicity. The findings of this study reveals that, flaxseed oil protects against dexamethasone induced skeletal muscle atrophy and protective effect may be due to flaxseed oil's antioxidant properties. However, further research is essential to prove the protective effects of flaxseed oil in some more studies mainly revealing its actions at cellular and molecular level.

Photoautotrophic Production of Docosahexaenoic Acid- and Eicosapentaenoic Acid-Enriched Biomass by Co-Culturing Golden-Brown and Green Microalgae

Marine microalgae offer a sustainable alternative source for the human diet’s essential omega-3-fatty acids, including docosahexaenoic acid (DHA, C22:6) and eicosapentaenoic acid (EPA, C20:5). However, none of them can produce DHA and EPA in a nutritionally balanced ratio of 1:1. As shown recently, the phototrophic co-cultivation of the golden-brown microalgae Tisochrysis lutea (DHA producer) with the green microalgae Microchloropsis salina (EPA producer) can provide microalgae biomass with a balanced DHA-to-EPA ratio with increased productivity compared to monocultures. This study evaluates whether other golden-brown (Isochrysis galbana) and green microalgae (Nannochloropsis oceanica, Microchloropsis gaditana) can enable the phototrophic batch production of omega-3 fatty acids in a nutritionally balanced ratio in co-culture. All co-cultivations applying a physically dynamic climate simulation of a repeated sunny summer day in Australia in LED-illuminated flat-plate gas lift photobioreactors resulted in increased biomass concentrations compared to their respective monocultures, achieving balanced DHA-to-EPA ratios of almost 1:1. Using urea instead of nitrate as a nitrogen source increased the EPA content by up to 80% in all co-cultures. Light spectra measurements on the light-adverted side of the photobioreactor showed that increased biomass concentrations in co-cultures could have been related to enhanced light use due to the utilization of different wavelengths of the two microalgae strains, especially with the use of green light (500–580 nm) primarily by golden-brown microalgae (I. galbana) and orange light (600–620 nm) predominantly used by green microalgae (N. oceanica). Phototrophic co-cultivation processes thus promise higher areal biomass yields if microalgae are combined with complimentary light-harvesting features.

Omega-3 Fatty Acid Therapy: A Review of Study Design Flaws, Quality, and Composition

There is marked heterogeneity in the clinical response to omega-3 fatty acid therapy with many authors documenting futility in large-scale trials, secondary re-analysis, and meta-analysis. The question of failure in the context of omega-3 therapy is multifactorial and complicated by the observation that fish intake has been broadly linked to significant risk reductions across a range of conditions. The question that remains is how can we resolve the discrepancy between pre-clinical evidence and epidemiology, which dually emphasize the benefit of omega-3 therapy against the limited success of large-scale clinical trials and smaller scale clinical studies that do not consistently report benefit and may even report harm, especially as it pertains to atrial fibrillation. We present three primary considerations that may clarify the supposed failures of omega-3 therapy: 1) correction for omega-3:omega-6 ratio and competition, 2) variation in the fatty acid composition and quality of omega-3 products, and 3) fundamental concerns pertaining to the omega-3 vehicle and its impact on omega-3 metabolism. While the predominant source of omega-3 therapy is supplements, they are typically not regulated prior to market like drugs and have significant variability in fatty acid composition, vehicle, oxidation, and quality control. Further, the individual response to omega-3 therapy is likely variable and dependent on ambient dietary conditions and inherited differences in endogenous desaturase activity, which has infrequently been accounted for in large studies. The net effect of these concerns should engender pharmaceutical and consumer companies alike to consider 1) refining trial design and 2) consider the role of oxidation in the failure of omega-3 products.

Chromosome-level genome assembly of chub mackerel (Scomber japonicus) from the Indo-Pacific Ocean

Chub mackerels (Scomber japonicus) are a migratory marine fish widely distributed in the Indo-Pacific Ocean. They are globally consumed for their high Omega-3 content, but their population is declining due to global warming. Here, we generated the first chromosome-level genome assembly of chub mackerel (fScoJap1) using the Vertebrate Genomes Project assembly pipeline with PacBio HiFi genomic sequencing and Arima Hi-C chromosome contact data. The final assembly is 828.68 Mb with 24 chromosomes, nearly all containing telomeric repeats at their ends. We annotated 31,656 genes and discovered that approximately 2.19% of the genome contained DNA transposon elements repressed within duplicated genes. Analyzing 5-methylcytosine (5mC) modifications using HiFi reads, we observed open/close chromatin patterns at gene promoters, including the FADS2 gene involved in Omega-3 production. This chromosome-level reference genome provides unprecedented opportunities for advancing our knowledge of chub mackerels in biology, industry, and conservation.

Abiotic stress applied to Tetraselmis subcordiformis reveals enhanced metabolic responses and increased production of Omega-3 fatty acids: A Metabolomic approach

The appeal of high value algal metabolites is certain due to their sustainability, low energy and space requirements. Yet, commercial-level production of such products is limited and has the potential to be enhanced. In microalgae Tetraselmis subcordiformis (T. subcordiformis) was subjected to four different stressors and the stress response was recorded in terms of changes in the metabolic profile of the strain. The stressors applied were nitrogen (N-starvation) and phosphorus starvation (P-starvation), high salinity, and cold stress. Although growth of the strain was impacted by application of all stressors, an increase of 34 % and 14.9 % in the protein content was noted for 100 PSU and P-starvation stress. Moreover, nitrogen content increase by 20 % and 5.8 % for 100 PSU and N-starvation stress. While the most common lipids for algae in high salinity and N-starvation stressors were triglycerides with α-linoleic (18:3), linoleic (18:2), and palmitic (16:0) fatty acids. Overall, compared to all stressors applied high salinity of 100 PSU enhanced the overall metabolic profile of T. subcordiformis.

Exploring the potential of Thraustochytrids and other microorganisms for sustainable omega-3 production: a comprehensive review of patents, perspectives, and scale-up strategies

Exploring the potential of Thraustochytrids and other microorganisms for sustainable omega-3 production: a comprehensive review of patents, perspectives, and scale-up strategies

Biotechnological production of omega-3 fatty acids: current status and future perspectives.

Omega-3 fatty acids, including alpha-linolenic acids (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), have shown major health benefits, but the human body's inability to synthesize them has led to the necessity of dietary intake of the products. The omega-3 fatty acid market has grown significantly, with a global market from an estimated USD 2.10 billion in 2020 to a predicted nearly USD 3.61 billion in 2028. However, obtaining a sufficient supply of high-quality and stable omega-3 fatty acids can be challenging. Currently, fish oil serves as the primary source of omega-3 fatty acids in the market, but it has several drawbacks, including high cost, inconsistent product quality, and major uncertainties in its sustainability and ecological impact. Other significant sources of omega-3 fatty acids include plants and microalgae fermentation, but they face similar challenges in reducing manufacturing costs and improving product quality and sustainability. With the advances in synthetic biology, biotechnological production of omega-3 fatty acids via engineered microbial cell factories still offers the best solution to provide a more stable, sustainable, and affordable source of omega-3 fatty acids by overcoming the major issues associated with conventional sources. This review summarizes the current status, key challenges, and future perspectives for the biotechnological production of major omega-3 fatty acids.

Dietary coriander (Coriandrum sativum L) oil improves growth, nutrient utilization, antioxidant status, tissue histomorphology and reduces omega-3 fatty acid production in Nile tilapia (Oreochromis niloticus)

Coriander (Coriandrum sativum L.) is recently emerging as an antimicrobial growth promoter in aquafeed formulations. To assess the effect of coriander seed oil in the feed of Nile tilapia five iso-nitrogenous (crude protein 40%) and iso-lipidic (crude lipid 7%) diets were prepared with graded levels of coriander oil i. e., 0, 5, 10, 15 and 20 g/Kg referred as C0, C5, C10, C15 and C20, respectively. The fish were fed with the experimental diets twice daily for a period of 60 days in triplicate. After the feeding experiment, there observed a linear pattern in weight gain with the dietary coriander oil levels. The expression of hepatic insulin like growth factor 1 gene increased significantly in coriander oil supplemented groups in dose dependent manner in hepatic tissues of tilapia. The viscerosomatic and hepatosomatic index decreased significantly in the coriander oil treated groups. The crude protein contents increased significantly in the experimental groups; however, it did not vary significantly in between the groups. The crude lipid contents increased significantly in the last three groups (C10, C15 and C20) compared to C0 and C5. The serum glucose content decreased significantly in the last three groups i.e., C10, C15 and C20 coriander fed groups compared to C0. Whereas, the HDL level increased significantly in the 20 g/Kg treatment group compared to rest of the groups. Catalase activity increased significantly in the liver tissue of coriander oil treated groups compared to control. The liver histomorphology showed signs of storage of carbohydrate or lipid reserves in the form of vacuoles in the control group. However, in the coriander supplemented groups there was a reduction in hepatic vacuolar structures. The appearance of intestinal villi was enriched in coriander oil supplemented groups via branching. The Δ6/Δ5 desaturase increased significantly in the experimental groups compared to control. The Δ4 desaturase and elongase decreased significantly beyond 6.3% and 11.7% of coriander oil in the diet, respectively. There observed a significant increase in the percentage of saturated fatty acids in dose dependent manner. However, the unsaturated fatty acids including omega-3 fatty acids decreased significantly with an increase dose of coriander oil in feed of Nile tilapia. It can be concluded from the above study that coriander essential oil can be used for better growth performance, intestinal nutrient absorption, antioxidant activity and decreasing hyperglycemia in Nile tilapia. However, higher inclusion level (above 5 g/Kg) led to decrease in the wholebody omega-3 fatty acid production.

Microbial production of docosahexaenoic acid (DHA): biosynthetic pathways, physical parameter optimization, and health benefits.

Omega-3 fatty acids, including docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), and α-linolenic acid (ALA), are essential polyunsaturated fatty acids with diverse health benefits. The limited conversion of dietary DHA necessitates its consumption as food supplements. Omega-3 fatty acids possess anti-arrhythmic and anti-inflammatory capabilities, contributing to cardiovascular health. Additionally, DHA consumption is linked to improved vision, brain, and memory development. Furthermore, omega-3 fatty acids offer protection against various health conditions, such as celiac disease, Alzheimer's, hypertension, thrombosis, heart diseases, depression, diabetes, and certain cancers. Fish oil from pelagic cold-water fish remains the primary source of omega-3 fatty acids, but the global population burden creates a demand-supply gap. Thus, researchers have explored alternative sources, including microbial systems, for omega-3 production. Microbial sources, particularly oleaginous actinomycetes, microalgae like Nannochloropsis and among microbial systems, Thraustochytrids stand out as they can store up to 50% of their dry weight in lipids. The microbial production of omega-3 fatty acids is a potential solution to meet the global demand, as these microorganisms can utilize various carbon sources, including organic waste. The biosynthesis of omega-3 fatty acids involves both aerobic and anaerobic pathways, with bacterial polyketide and PKS-like PUFA synthase as essential enzymatic complexes. Optimization of physicochemical parameters, such as carbon and nitrogen sources, pH, temperature, and salinity, plays a crucial role in maximizing DHA production in microbial systems. Overall, microbial sources hold significant promise in meeting the global demand for omega-3 fatty acids, offering an efficient and sustainable solution for enhancing human health.

Eutrophication effect on production and transfer of omega-3 fatty acids in boreal lake food webs

Eutrophication, i.e. increasing level of nutrients and primary production, is a central environmental change of lakes globally with wide effects on food webs. However, how eutrophication affects the synthesis of physiologically essential biomolecules (omega-3 fatty acids) and their transfer to higher trophic levels at the whole food web level is not well understood. We assessed food web (phytoplankton, zooplankton, and fish) biomass, community structure and fatty acid content (eicosapentaenoic acid [EPA], and docosahexaenoic acid [DHA]), together with fatty acid specific primary production in 12 Finnish boreal lakes covering the total nutrient gradient from oligotrophic to highly eutrophic lakes (4–140 μg TP l−1; 413–1814 μg TN l−1). Production was measured as the incorporation of 13C-NaHCO3 into phytoplankton fatty acids and differentiated into volumetric production (production per litre of water) and productivity (production per phytoplankton biomass). Increases in nutrients led to higher biomass of phytoplankton, zooplankton and fish communities while also affecting community composition. Eutrophication negatively influenced the contribution of phytoplankton biomass preferentially grazed by zooplankton (<35 μm). Total volumetric production saturated at high phytoplankton biomass while EPA volumetric production presented a logarithmic relationship with nutrient increase. Meanwhile, total and EPA productivity had unimodal responses to this change in nutrients. DHA volumetric production and productivity presented large variation with increases in total phosphorus, but a unimodal model best described DHA changes with eutrophication. Results showed that eutrophication impaired the transfer of EPA and DHA into zooplankton and fish, showing a clear negative impact in some species (e.g. perch) while having no effect in other species (e.g. roach, ruffe). Results show non-linear trends in fatty acid production and productivity peaking at nutrient concentrations 22–35 μg l−1 TP followed by a gradual decrease.

Comparative Transcriptome Analysis Reveals the Effect of Aurantiochytrium sp. on Gonadal Development in Zebrafish.

Aurantiochytrium sp. has received much attention as a potential resource for mass production of omega-3 fatty acids, which contribute to improved growth and reproduction in aquatic animals. In this study, we evaluated the gonadal index changes in zebrafish supplemented with 1-3% Aurantiochytrium sp. crude extract (TE) and the effects of ex vivo environmental Aurantiochytrium sp. on oocytes. 1% TE group showed significant improvement in the gonadal index, and both in vitro incubation and intraperitoneal injection promoted the maturation of zebrafish oocytes. In contrast, the transcriptome revealed 576 genes that were differentially expressed between the 1% TE group and the control group, including 456 up-regulated genes and 120 down-regulated genes. Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) pathway analysis of differentially expressed genes indicated that Aurantiochytrium sp. potentially affects pathways such as lipid metabolism, immune regulation, and oocyte development in zebrafish. The results of this study enriched the knowledge of Aurantiochytrium sp. in regulating gonadal development in zebrafish and provided a theoretical basis for its application in aquaculture.

Omega-3 enriched chick diet reduces the foraging areas of breeders in two closely related shearwaters from contrasting marine environments.

Seabirds have evolved several life-history characteristics to help buffer environmental stochasticity. However, particularly during the breeding season, seabirds may be affected by reductions in prey availability and localised oceanographic conditions caused by variations in the environment. The increase in sea surface temperature, triggered by accelerated global warming, is impairing phytoplankton production of omega-3 fatty acids (FAs). Here, we assessed the ecological role of omega-3 FAs on chick development and subsequently on breeder foraging behaviour in two closely related shearwater species foraging in contrasting marine environments. We supplemented chicks with omega-3 FA pills or with control placebo pills and monitored chick growth, chick health status and breeder at-sea foraging behaviour using global positioning system devices. We found that omega-3 chick supplementation reduced the 95% kernel utilization distribution of short trips of Cape Verde shearwaters, but overall, breeders kept a similar foraging pattern between treatments, potentially influenced by predictable prey patches off the West African coast. In contrast, for Cory's shearwaters, the parents of the omega-3 group greatly reduced the foraging effort. This suggests that the proximity to productive prey patches around the colony may help birds to adjust their effort and, therefore, energy expenditure, to changes in the development of their offspring, as driven by their nutritional status. Overall, our results suggest a link between a chick diet enriched in omega-3 FAs and parental foraging effort, providing insight into their ability to cope with a changing and increasingly stochastic marine environment.

Production of omega-3 concentrate from lemuru fish (Sardinella longiceps) oil by two-step urea complexation

Lemuru fish (Sardinella longiceps) oil is a by-product containing polyunsaturated fatty acids (PUFA) that is important for the prevention of several diseases. For daily intake, saturated fatty acids should be removed from fish oil to obtain PUFA concentrates. Various methods have been observed in producing omega-3 concentrates. The objective of this study was to produce the omega-3 concentrate from lemuru fish oil using a two-step urea complexation method and to characterize the omega-3 product. Lemuru fish oil was saponified and purified to produce fatty acids and urea was added to the fatty acids to obtain crystal complexes. In this study, crystallization was carried out at -20 °C for 24 h with an oil-urea ratio of 1:0.625, 1:1.25, and 1:2.5. The results showed that the highest content of omega-3 (ALA, DHA, EPA) was reached at a ratio of fish oil-urea of 1:0.625. Based on the FTIR spectrum analysis, omega-3 concentrate contained the specific spectrum indicated by HC=CH trans, -C=O (ester), and -C-O (acid) groups. UV-Vis spectra analysis showed that light exposure affected the stability of omega-3 concentrate, as is evident by the hypsochromic shift of the resulting spectrum.

Full replacement of fish oil with algae oil in farmed Atlantic salmon (Salmo salar) – Debottlenecking omega 3

The global goal of developing sustainable aquafeed has faced increased complexity in sourcing raw materials. The limited availability of fish oil (FO) is a well-known bottleneck for the aquaculture industry and pairing it with EFSA (EFSA CONTAM, 2018) reduced tolerable weekly intake of marine contaminants [polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) and dioxin-like polychlorinated biphenyls (DLPCB)] creates another challenge for wild caught FO and its use in fish feed. In recent years, commercial algal alternatives have increasingly become available. Not only would omega-3 sources from algae reduce the reliance on FO; it would allow for restoration of the long chain omega-3 levels in farmed salmon. To this end, a study was conducted to establish knowledge on full replacement of FO by algae oil (Schizochytrium sp.) in Atlantic salmon with the aim of reducing contaminants levels in the fillet and maintaining the level of omega-3 fatty acid (FA), growth performance, health, and final product quality. Atlantic salmon (531 g) were distributed into twelve 5 × 5 × 5 m sea cages and fed one of four diets for 369 days: a control diet (Control) containing FO + rapeseed oil (VO1); a diet where AlgaPrime (AP) replaced 50% of the sum of EPA + DHA from FO (50AP + VO1); a diet where AP replaced 100% of the sum of EPA + DHA from FO (100AP + VO1), and a diet the same as the previous but using linseed instead of rapeseed oil (VO2; 100AP + VO2). All diets were balanced for key micronutrients. At the end of the trial, zootechnical parameters were obtained, health and welfare assessed, and final fillet quality analysed for contaminants and fillet quality post slaughter. Full replacement of FO significantly reduced the levels of PCDD/F and DLPCB in the fillet of 4 kg salmon by 70% and 79% respectively for 100AP + VO1 and 40% and 43% respectively for 100AP + VO2 fed fish. Fish gained an average of 3.7 kg across treatments (average final weight 4235.8 g ± 191.8); almost an 8-fold increase for all treatments. No significant differences were found among diets for performance, feed intake, gut health, histology, welfare, pigmentation, or fillet quality. This study demonstrates that AlgaPrime can be used to fully replace FO in Atlantic salmon grower feed without negative effects, achieving an important impact on food safety and sustainability for aquafeed producers and salmon consumers.

Thraustochytrid hosts for expression of proteins relevant to SARS-CoV-2 intervention.

The emergence of COVID-19 as a global pandemic had sharply illustrated the limitations of research and development pipelines and scaled manufacturing. Although existing vaccines were created in record time, global deployment remains limited by regional production scales. Similarly, the most effective treatments for infected COVID-19 patients are also constrained by production scales as well as by the cost of production and thus expense per treatment. The need to produce these interventions more cost-effectively, at larger scales, in less time while retaining high quality is paramount. The ConamaxTM platform is based on a Thraustochytrid-an order of microorganisms well established in industry for world-scale production of omega-3 fatty acids by fermentation. Thraustochytrids, and the species Aurantiochytrium acetophilum in particular, possess a number of innate qualities which make it ideal for production of monoclonal antibodies and other biotherapeutic proteins. In this study, the Conamax system was used to produce several targets which may be relevant as interventions in the fight against COVID-19; an anti-SARS-CoV-2 antibody (CR3022), tocilizumab, and the ACE2 receptor. Our system was capable of producing all of these targets and each was assayed in vitro for an activity which confirmed proper structural folding. Purified CR3022 antibody produced from Conamax was capable of reducing the cytopathic effect of SARS-CoV-2. Conamax-derived tocilizumab was shown to bind to its target IL6R. Both the full-length and soluble versions of ACE2 protein produced in the Conamax platform exhibited ACE2-specific proteolytic activity. These data indicate that the Conamax platform has great potential in the production of therapeutic agents.

Poly-Vinylidene Fluoride (PVDF)/ Span-85 Membrane for Omega-3 PUFA Concentration: Membrane Performance and Fouling Analysis

Abstract: For increasing the efficiency of the omega-3 production, the effect of span-85 surfactant as a hydrophobic agent (0, 1, 2, 3 and 4 wt%) on the formation of a porous structure in a sub-layer PVDF membrane was studied. Also, the cross-sectional morphology of PVDF membranes was analyzed using scanning electron microscopy (SEM) and the surface property was evaluated using contact angle test. The capacity of the membranes to concentrate omega-3 was examined by the filtration of lantern fish oil. Also, the fouling of the membrane caused by oil filtration was evaluated. All filtration tests were performed in batch mode. Results of the SEM images demonstrated that the addition of span-85 resulted in the forming of a membrane with a denser and more hydrophobic structure. The addition of 2 wt% span-85 increased the omega-3 concentration, while the higher level of span-85 showed a negative effect. The best efficiency of the membrane was 42.64 wt% which was obtained by PVDF/2 wt% span-85. This efficiency was about 11% higher than the control PVDF (0 wt%). Taken together, the presence of span-85 affected the phase inversion process during the membrane formation, which improved omega-3 concentration. Moreover, the more hydrophobic surface of the membrane resulted in higher cake formation. Keywords: Omega-3 PUFA, Poly-vinyldene fluoride (PVDF), Membranes performance, Span-85, Concentration, Fouling analysis.

Poly-Vinylidene Fluoride (PVDF)/ Span-85 Membrane for Omega-3 PUFA Concentration: Membrane Performance and Fouling Analysis

Abstract: For increasing the efficiency of the omega-3 production, the effect of span-85 surfactant as a hydrophobic agent (0, 1, 2, 3 and 4 wt%) on the formation of a porous structure in a sub-layer PVDF membrane was studied. Also, the cross-sectional morphology of PVDF membranes was analyzed using scanning electron microscopy (SEM) and the surface property was evaluated using contact angle test. The capacity of the membranes to concentrate omega-3 was examined by the filtration of lantern fish oil. Also, the fouling of the membrane caused by oil filtration was evaluated. All filtration tests were performed in batch mode. Results of the SEM images demonstrated that the addition of span-85 resulted in the forming of a membrane with a denser and more hydrophobic structure. The addition of 2 wt% span-85 increased the omega-3 concentration, while the higher level of span-85 showed a negative effect. The best efficiency of the membrane was 42.64 wt% which was obtained by PVDF/2 wt% span-85. This efficiency was about 11% higher than the control PVDF (0 wt%). Taken together, the presence of span-85 affected the phase inversion process during the membrane formation, which improved omega-3 concentration. Moreover, the more hydrophobic surface of the membrane resulted in higher cake formation.

Effect of packaging and encapsulation on the oxidative and sensory stability of omega-3 supplements.

Omega-3 fatty acid consumption is getting more common due to its positive impacts on human health. Since consumers cannot get their omega-3 needs from natural sources, omega-3-rich products play an essential part in the diet. However, they are highly susceptible to oxidation; thus, storage conditions affect their quality. Product form is also another critical factor for stability. In this study, fatty acid composition, oxidative stability, and sensory properties of different omega-3 products having varied packaging types were investigated. Moreover, the effect of consumer behavior regarding the recommended usage was assessed during storage. Syrup forms (maximum values at the end of the storage: PV=44.6meq/kg oil for S32, p-AV=16.87 for S22, and TOTOX=96.94 for S11) are more susceptible to oxidation than capsule (maximum values at the end of the storage: PV=7.62 meq/kg oil for C31, p-AV=19.58 for C12, and TOTOX=30.44 for C12) and chewable forms (maximum values at the end of the storage: PV=26.14 meq/kg oil for G12, p-AV=13.47 for G12, and TOTOX=65.76 for G12). In addition, capsules complied more with limit values during storage and were better protected according to the sensory scores. The aroma and taste of the omega-3 products generally changed in a negative manner during storage. Capsulated samples were better protected according to the sensory evaluation scores at the end of the storage period. Fish oil samples belonging to the same company but provided from different stores showed significant differences, which is an indicator of nonstandard raw material, ingredient, or processing.

Dark stress for improved lipid quantity and quality in bioprospected acid-tolerant green microalgae.

The cost of microalgae cultivation is one of the largest limitations to achieving sustainable, large-scale microalgae production of commercially desirable lipids. Utilizing CO2 as a 'free' carbon source from waste industrial flue gas emissions can offer wide-ranging cost savings. However, these gas streams typically create acidic environments, in which most microalgae cannot survive due to the concentration of CO2 and the presence of other acidic gasses such as NO2 and SO2. To address this situation, we investigated growth of a mixed acid-tolerant green microalgal culture (91% dominated by a single Coccomyxa sp. taxon) bioprospected at pH 2.8 from an acid mine drainage impacted water body. The culture was grown at pH 2.5 and fed with a simulated flue gas containing 6% CO2 and 94% N2. On reaching the end of the exponential growth phase, the culture was exposed to either continued light-dark cycle conditions or continual dark conditions. After three days in the dark, the biomass consisted of 28% of lipids, which was 42% higher than at the end of the exponential phase and 55% higher than the maximum lipid content achieved under light/dark conditions. The stress caused by being continually in the dark also favoured the production of omega-3 and omega-6 polyunsaturated fatty acids (PUFAs; 19.47% and 21.04%, respectively, after 7 days) compared to 7-days of light-dark treatment (1.94% and 9.53%, respectively) and showed an increase in nitrogen content (C:N ratio of 6.4) compared to light-dark treatment (C:N ratio of 11.9). The results of the research indicate that use of acid tolerant microalgae overcomes issues using flue gasses that will create an acidic environment and that applying dark stress is a low-cost stressor stimulates production of desirable dietary lipids.

Synechococcus elongatus PCC 7942 as a Platform for Bioproduction of Omega-3 Fatty Acids.

Alpha-linolenic acid and stearidonic acid are precursors of omega-3 polyunsaturated fatty acids, essential nutrients in the human diet. The ability of cyanobacteria to directly convert atmospheric carbon dioxide into bio-based compounds makes them promising microbial chassis to sustainably produce omega-3 fatty acids. However, their potential in this area remains unexploited, mainly due to important gaps in our knowledge of fatty acid synthesis pathways. To gain insight into the cyanobacterial fatty acid biosynthesis pathways, we analyzed two enzymes involved in the elongation cycle, FabG and FabZ, in Synechococcus elongatus PCC 7942. Overexpression of these two enzymes led to an increase in C18 fatty acids, key intermediates in omega-3 fatty acid production. Nevertheless, coexpression of these enzymes with desaturases DesA and DesB from Synechococcus sp. PCC 7002 did not improve alpha-linolenic acid production, possibly due to their limited role in fatty acid synthesis. In any case, efficient production of stearidonic acid was not achieved by cloning DesD from Synechocystis sp. PCC 6803 in combination with the aforementioned DesA and DesB, reaching maximum production at 48 h post induction. According to current knowledge, this is the first report demonstrating that S. elongatus PCC 7942 can be used as an autotrophic chassis to produce stearidonic acid.