Linoleic Acid Production Research Articles

Crucial amino acids identified in Δ12 fatty acid desaturases related to linoleic acid production in Perilla frutescens.

Perilla oil from the medicinal crop Perilla frutescens possess a wide range of biological activities and is generally used as an edible oil in many countries. The molecular basis for its formation is of particular relevance to perilla and its breeders. Here in the present study, four PfFAD2 genes were identified in different perilla cultivars, PF40 and PF70, with distinct oil content levels, respectively. Their function was characterized in engineered yeast strain, and among them, PfFAD2-1PF40, PfFAD2-1PF70 had no LA biosynthesis ability, while PfFAD2-2PF40 in cultivar with high oil content levels possessed higher catalytic activity than PfFAD2-2PF70. Key amino acid residues responsible for the enhanced catalytic activity of PfFAD2-2PF40 was identified as residue R221 through sequence alignment, molecular docking, and site-directed mutation studies. Moreover, another four amino acid residues influencing PfFAD2 catalytic activity were discovered through random mutation analysis. This study lays a theoretical foundation for the genetic improvement of high-oil-content perilla cultivars and the biosynthesis of LA and its derivatives.

Screening and Identification of High-Yielding Strains of Conjugated Linoleic Acid and Optimization of Conditions for the Conversion of CLA.

Conjugated linoleic acid (CLA) is a class of naturally occurring octadecadienoic acid in humans and animals and is a general term for a group of conformational and positional isomers of linoleic acid. In order to obtain the development of excellent lactic acid strains with a high production of conjugated linoleic acid, 32 strains with a possible CLA conversion ability were obtained by initial screening using UV spectrophotometry, and then the strains were re-screened by gas chromatography, and finally, the strain with the highest CLA content was obtained. The strains were optimized for cultivation by changing the amount of substrate addition, inoculum amount, and fermentation time. The results showed that the yield of the experimentally optimized strain for the conversion of conjugated linoleic acid could reach 94.68 ± 3.57 μg/mL, which was 74.4% higher than the initial yield of 54.28 ± 2.12 μg/mL of the strain. The results of this study can provide some basis for the application of conjugated linoleic acid production by Lactobacillus paracasei in the fermentation of lactic acid bacteria.

The Composition of Volatiles and the Role of Non-Traditional LOX on Target Metabolites in Virgin Olive Oil from Autochthonous Dalmatian Cultivars.

The lipoxygenase pathway has a significant influence on the composition of the volatile components of virgin olive oil (VOO). In this work, the influence of the maturity index (MI) on the activity of the lipoxygenase enzyme (LOX) in the fruits of the autochthonous Dalmatian olive cultivars Oblica, Levantinka and Lastovka was studied. The analysis of the primary oxidation products of linoleic acid in the studied cultivars showed that LOX synthesises a mixture of 9- and 13-hydroperoxides of octadecenoic acid in a ratio of about 1:2, which makes it a non-traditional plant LOX. By processing the fruits of MI~3, we obtained VOOs with the highest concentration of desirable C6 volatile compounds among the cultivars studied. We confirmed a positive correlation between MI, the enzyme activity LOX and the concentration of hexyl acetate and hexanol in cultivars Oblica and Lastovka, while no positive correlation with hexanol was observed in the cultivar Levantinka. A significant negative correlation was found between total phenolic compounds in VOO and LOX enzyme activity, followed by an increase in the MI of fruits. This article contributes to the selection of the optimal harvest time for the production of VOOs with the desired aromatic properties and to the knowledge of the varietal characteristics of VOOs.

Optimization of Conjugated Linoleic Acid and Eicosapentaenoic Acid Production from Sesame Waste by Response Surface Methodology

Conjugated linoleic acid (CLA) and eicosapentaenoic acid (EPA) have been recognized for their physiological functions and potential as dietary supplements. This study is aimed at investigating the production and enhancing the efficiency of these two acids from Lactiplantibacillus plantarum using sesame waste as a natural, cost-effective, and readily available culture medium. Response surface methodology (RSM) was employed to optimize the production of CLA and EPA in a solid bed system using sesame waste paste as the fermentation substrate. The main processing parameters, including three humidity levels (60%, 70%, and 80%), three inoculum percentages (2%, 4%, and 6% v/v), and three fermentation temperatures (30°C, 37°C, and 44°C), were optimized. An experiment was conducted to validate the determined conditions, and a strong correlation was observed between the experimental results and the predictions made by the software. The optimal conditions for CLA and EPA production were determined to be an inoculation level of 6% with 80% humidity and at 37°C. Gas chromatography analysis of the fermented sesame waste medium revealed that the highest yields of CLAc9t11 and CLAt10c12, as well as eicosapentaenoic acid, were obtained in the medium fermented with 80% humidity and 6% inoculation at 37°C. The respective percentages of these fatty acids in the total fatty acid composition were found to be 0.351% (w/v) and 0.1% (w/v) for CLA and 0.139% (w/v) for EPA under the optimized conditions. These findings contribute to the understanding of CLA and EPA production and highlight the potential of L. plantarum and sesame waste as a fermentation substrate for their efficient production.

Metabolomics analysis of physicochemical properties associated with freshness degradation in frozen Antarctic krill (Euphausia superba)

This study aimed to determine the effect of different frozen temperatures during storage on the quality of Antarctic krill (Euphausia superba) and assess the change at the metabolite level via a combination of physicochemical property analysis, liquid chromatography–tandem mass spectrometry (LC–MS) based non–targeted metabolomics profiling. Regarding samples stored at –20 °C, the expressions of 7055 metabolites were elevated, while 2313 were downregulated. Lipids and lipid molecules had the highest proportion of differential metabolites. A total of 432 discriminatory metabolites with Kyoto Encyclopedia of Genes and Genomes (KEGG) IDs was obtained. We also observed that the concentrations of differential bitter free amino acids (FAAs) and oxidation products of arachidonic and linoleic acid increased. Moreover, as the storage temperature increased, the freshness, umami, and sweetness components were considerably reduced. Furthermore, results indicated that the color, pH and water–holding capacity (WHC) were potential indicators of quality deterioration, while inosinic acid was a probable biomarker for umami degradation of frozen Antarctic krill. In conclusion, this study demonstrates that storage at lower temperatures can be beneficial for maintaining the freshness of Antarctic krill from macro and micro perspectives.

Formation of Furan from Linoleic Acid Thermal Oxidation: (E,E)-2,4-Decadienal as a Critical Intermediate Product.

The linoleic acid reaction models were set at 150 °C for 120 min, and its oxidation process was monitored by nuclear magnetic resonance (NMR) and gas chromatography-mass spectrometry (GC-MS). Results showed that no furan was formed from linoleic acid without heating, while furan accumulated throughout the heating process. Linoleic acid ran out within 30 min, which indicated that furan was formed mainly from the intermediate oxidation products of linoleic acid after 30 min. It should be noticed that the content of (E,E)-2,4-decadienal reached maximum once the linoleic acid ran out and then decreased with the formation of furan. Multivariate statistical analysis suggested that (E,E)-2,4-decadienal was the most important aldehyde related to furan formation during linoleic acid oxidation. To prove this assumption, the variation of furan from (E,E)-2,4-decadienal reaction models heating at 150 °C for 60 min was also studied. Results showed that the content of furan increased with the oxidation of (E,E)-2,4-decadienal. Furthermore, NMR and GC-MS data proved that (E,E)-2,4-decadienal could be oxidized to 4,5-epoxy-(E)-2-decenal. In conclusion, our results supported (E,E)-2,4-decadienal and trans-4,5-epoxy-(E)-2-decenal as critical intermediate products of furan formation from linoleic acid oxidation.

Mechanisms of the Formation of Nonvolatile and Volatile Oxidation Products from Methyl Linoleic Acid at High Temperatures.

The impact of the oxidation of linoleic acid cannot be overlooked in daily food consumption. This study used gas chromatography-mass spectrometry (GC-MS) to identify both nonvolatile oxidation products and volatile oxidation products of methyl linoleic acid at 180 °C and density function theory to investigate oxidation mechanisms. An analysis of nonvolatile oxidation products revealed the presence of three primary oxidation products. The three primary oxidation products were identified as hydroperoxides, peroxide-linked dimers, and heterocyclic compounds in a ratio of 2.70:1:3.69 (mmol/mmol/mmol). The volatile components of secondary oxidation products were found including aldehydes (40.77%), alkanes (19.89%), alcohols (9.02%), furans (6.11%), epoxides (0.46%), and acids (2.50%). DFT calculation proved that the secondary oxidation products mainly came from peroxides (77%). Finally, we look forward to our research contributing positively to lipid autoxidation and human health.

Multi-omics analysis reveals activation of jasmonate synthesis and modulation of oxidative stress responses in boron deficient pea shoots

Boron (B) is vital for plant growth and development. Understanding aboveground tissue responses to B deficiency can offer insights into enhancing plant productivity under B-limited conditions. Here we show from comprehensive metabolomics analysis that during B deficiency treatment the number of differentially expressed metabolites (DEMs) increases from 64 to 193 in pea shoots. Boron deficiency intensified oxidative stress and led to decreased ascorbate and glutathione levels. Integrative metabolomic and transcriptomic analyses revealed activation of the phenylpropanoid biosynthesis and α-linolenic acid metabolic pathways under B deficiency. Metabolites of the phenylpropanoid pathway, including p-coumaryl alcohol and sinapic acid, increased, accompanied by upregulation of related biosynthetic genes. A decline in total flavonoid content suggested that the activation of phenylpropanoid synthesis might indicate increased lignin accumulation, thus affecting cell wall metabolism. The alterations in these pathways at specific time point highlighted the dynamic resource allocation caused by B deficiency, providing insights into metabolic reprogramming in pea shoot apices. In the α-linolenic acid pathway, B deficiency led to accumulation of 17-hydroxylinolenic acid, jasmonic acid (JA), and jasmonoyl-L-isoleucine, with upregulated JA biosynthesis genes. Jasmonates are proposed to play a key role in reprogramming shoot development particularly modulating membrane and cell wall structure and function under B deficiency. Increased levels of oxidation products of linoleic acid suggest changes to membrane structure and are also consistent with changes to the redox status of cells under B deficiency. Collectively, our findings elucidated intricate B deficiency responses at both the metabolome and transcriptome levels and identified potential targets for breeding crops tolerant to B deficiency, including jasmonate signalling, phenylpropanoid biosynthesis, and antioxidant capacity.

Foliar Spraying of Chlorpyrifos Triggers Plant Production of Linolenic Acid Recruiting Rhizosphere Bacterial Sphingomonas sp.

Plants have developed an adaptive strategy for coping with biotic or abiotic stress by recruiting specific microorganisms from the soil pool. Recent studies have shown that the foliar spraying of pesticides causes oxidative stress in plants and leads to changes in the rhizosphere microbiota, but the mechanisms by which these microbiota change and rebuild remain unclear. Herein, we provide for the first-time concrete evidence that rice plants respond to the stress of application of the insecticide chlorpyrifos (CP) by enhancing the release of amino acids, lipids, and nucleotides in root exudates, leading to a shift in rhizosphere bacterial community composition and a strong enrichment of the genus Sphingomonas sp. In order to investigate the underlying mechanisms, we isolated a Sphingomonas representative isolate and demonstrated that it is both attracted by and able to consume linolenic acid, one of the root exudates overproduced after pesticide application. We further show that this strain selectively colonizes roots of treated plants and alleviates pesticide stress by degrading CP and releasing plant-beneficial metabolites. These results indicate a feedback loop between plants and their associated microbiota allowing to respond to pesticide-induced stress.

Investigation of cold plasma technique as an alternative to conventional alkalization of cocoa powders

In the production of cocoa, a crucial process called “Alkalization” or “Dutching” has been used to reduce its acidity, bitterness and astringency as well as modify its solubility and color. It is a time- and energy-consuming process. It was investigated whether it is possible to replace the conventional alkalization with the cold plasma (CP) technique. We discover that atmospheric pressure plasma jet (APPJ) CP treatment is capable of reducing the lightness values, improving the solubility, and decreasing the acidic perception of natural cocoa powders as well as protecting bioactive compounds (total phenolic and flavonoid content) of natural cocoa powders, consuming ∼65% less time than the traditional method and without the need for external expenditures such as chemicals, high pressure, or aeration. Moreover, CP treatment did not increase the total ash content and thus water-holding capacity of powders unlike the conventional alkalization, which caused a 40% and 42% increase, respectively. The SEM micrographs demonstrated that CP treatment caused etching on the surface and removed the layer of protein-polyphenol-cell wall complex. FTIR spectra showed the incorporation of hydrophilic functional groups on the surface after CP treatment. CP treatment effectively reduced the acidic fractions of cocoa powder, but caused to the oxidation of cocoa butter and the formation of decomposition products of oleic and linoleic acid. Finally, this is a pioneering study for replacing an alkalization process step that has been used since the 19th century and has no alternative, and the results seem to be very promising for further detailed studies and pilot- and industrial-scale trials.

A potential probiotic Enterococcus faecium isolated from camel rumen, fatty acids biotransformation, antilisteria activity and safety assessment

The probiotic features of a new Enterococcus faecium strain isolated from camel rumen were investigated. The isolate identified as E. faecium 96B4 exhibited notable tolerance to gastrointestinal conditions, with high cell viability at pH 1.5 after 3 h (about 7.48 log10 cfu mL−1). Besides complete inhibition of Listeria monocytogenes growth, E. faecium 96B4 showed high hydrophobicity, auto- and co-aggregations abilities. It showed 76.33% cholesterol assimilation ability and boosted the extracellular unsaturated fatty acid content up to 25.53% in the presence of soybean oil as a substrate. Moreover, 96.17 ± 3.52 μg mL−1 conjugated linoleic acid production and 2.56 fold increase in oleic acid content were highlighted. Significant diacetyl production ability was also demonstrated. E. faecium 96B4 passed the safety assessment successfully. The association between the microbiome and host health makes the camel, as a unique animal, a rich source of beneficial microorganism candidates for designing future foods.

Deletion of NRF2 disturbs composition, morphology, and differentiation of the murine tail epidermis in chronological aging.

NRF2 is a master regulator of the cellular protection against oxidative damage in mammals and of multiple pathways relevant in the mammalian aging process. In the epidermis of the skin NRF2 contributes additionally to the formation of an antioxidant barrier to protect from environmental insults and is involved in the differentiation process of keratinocytes. In chronological aging of skin, the capacity for antioxidant responses and the ability to restore homeostasis after damage are impaired. Surprisingly, in absence of extrinsic stressors, NRF2 deficient mice do not show any obvious skin phenotype, not even at old age. We investigated the differences in chronological epidermal aging of wild type and NRF2-deficient mice to identify the changes in aged epidermis that may compensate for absence of this important transcriptional regulator. While both genotypes showed elevated epidermal senescence markers (increased Lysophospholipids, decreased LaminB1 expression), the aged NRF2 deficient mice displayed disturbed epidermal differentiation manifested in irregular keratin 10 and loricrin expression. The tail skin displayed less age-related epidermal thinning and a less pronounced decline in proliferating basal epidermal cells compared to the wildtype controls. The stratum corneum lipid composition also differed, as we observed elevated production of barrier protective linoleic acid (C18:2) and reduced abundance of longer chain saturated lignoceric acid (C24:0) among the stratum corneum fatty acids in the aged NRF2-deficient mice. Thus, despite epidermal differentiation being disturbed in aged NRF2-deficient animals in homeostasis, adaptations in keratinocyte proliferation and barrier lipid synthesis could explain the lack of a more severe phenotype.

Mining and application of constitutive promoters from Rhodosporidium toruloides

Rhodosporidium toruloides is an oleaginous yeast under development with promising industrial applications. Since promoters of different strengths have been demonstrated as an efficient strategy to fine-tune gene expression in synthetic biology, a set of constitutive promoters with strengths varying over 2 orders of magnitude were identified in R. toruloides through transcriptome analysis under different growth conditions. Promoter candidates were first cloned and characterized using an enhanced green fluorescent protein (EGFP) as a reporter under eight conditions, and 31 promoters were identified with strength varied from 0.1 to 19.0 folds of the commonly used strong promoter of the glyceraldehyde-3-phosphate dehydrogenase gene (PGPD1). The resultant promoters were then used to optimize the linoleic acid biosynthetic pathway in R. toruloides in different media, including the use of lignocellulosic hydrolysate as the fermentation substrate, and improved the production of linoleic acid by up to 214.2% in minimal medium, with the highest production of 350.3 mg/L in Yeast Peptone Dextrose medium. This work has enriched the promoter library of R. toruloides, and helped develop R. toruloides as a platform organism for applications in biomanufacturing and synthetic biology.

Intense Pulsed Light Attenuates Oxidative Stress in Perennial Allergic Conjunctivitis.

Objective: To assess the effects of intense pulsed light (IPL) on oxidative stress (OS) in perennial allergic conjunctivitis (PAC). Background: IPL treatment has been proven effective for dry eye disease (DED). However, we have observed that, after IPL treatment, some patients with DED combined with allergic conjunctivitis (AC), an immune response condition in which excessive OS causes and exacerbates inflammatory damage, not only show an improvement in eye dryness, but also their AC-related eye itching is relieved. The mechanism by which IPL inhibits allergic reactions is not clear. Methods: Five patients with moderate-to-severe PAC were given two IPL treatments on the periorbital skin with a 2-week interval. Visual analog scale (VAS) scores and signs of AC, including eye redness and conjunctival follicles, were assessed before the first treatment (day 1) and 2 weeks after the second treatment (day 30). Tears were also collected at the same time, and lipid oxidation (LPO) metabolite analysis was performed using liquid chromatography tandem mass spectrometry (LC-MS/MS) to investigate the effects of IPL on OS response. Results: The average VAS score significantly decreased with treatment (30.2 for day 1, 10.6 for day 30; p < 0.001). The general signs of PAC showed no difference (p > 0.05). LPO metabolite analysis revealed that 17,18-diHETE, which is an oxidation product of eicosapentaenoic acid, and 13-OXoODE, which is an oxidation product of linoleic acid, are significantly downregulated after IPL treatment. Conclusions: The photothermal effect of IPL attenuates OS in PAC, and this seems to be one of the mechanisms by which IPL treatment improves PAC. Clinical Trial Registration number: ChiCTR1900022202.

Linoleic acid enrichment of cheese by okara flour and Geotrichum candidum overexpressing Δ12 fatty acid desaturase.

Mold-ripened cheeses have low levels of unsaturated fatty acids (UFAs). Geotrichum candidum is an adjunct culture for the development of Geotrichum-ripened cheese but has a low ability to produce high levels of UFAs. Δ12 fatty acid desaturase (FADS12) is a pivotal enzyme that converts oleic acid (OA) to linoleic acid (LA) and plays a vital role in UFA biosynthesis. By investigating FADS12 catalytic activity from various species with OA substrates, we found that FADS12 from Mucor circinelloides (McFADS12) had the highest catalytic activity for OA. In the current study, a plasmid harboring McFADS12 was constructed and overexpressed in G. candidum. Our results showed that LA production increased to 31.1 ± 1.4% in engineered G. candidum - three times higher than that in wild-type G. candidum. To enhance LA production, an exogenous substrate (OA) was supplemented, and the yield of LA was increased to 154 ± 6 mg L-1 in engineered G. candidum. Engineered G. candidum was used as an adjunct culture for Geotrichum-ripened cheese production. The LA level reached 74.3 ± 5.4 g kg-1 cheese, whereas the level of saturated fatty acids (SFAs) decreased by 9.9 ± 0.5%. In addition, the soybean byproduct (okara) was introduced into the engineered G. candidum growth and the level of LA increased to 126 ± 4 g kg-1 cheese and the percentage of UFAs:SFAs increased from 0.8:1 to 1.3:1. This study offers a suitable technology for converting SFAs to UFAs in Geotrichum-ripened cheeses and provides a novel trend for converting soybean waste into a value-added product. © 2022 Society of Chemical Industry.

The mechanistic study of adding polyunsaturated fatty acid to promote triterpenoids production in submerged fermentation of Sanghuangporus baumii

BackgroundTriterpenoids are the major bioactive constituents of the edible and medicinal mushroom Sanghuangporus baumii. The polyunsaturated fatty acid is an excellent stimulator that promotes the production of triterpenoids significantly. In this study, the detailed underlying mechanisms between linolenic acid and triterpenoids production were further investigated. ResultsGC-MS analysis, the release of cell constituents, SEM observation and MDA content determination showed the changes in cell membrane composition, permeability and morphology. A higher unsaturated/saturated fatty acid ratio, better membrane permeability and fluidity, and enhanced degree of mycelial wrinkles and lipid peroxidation were observed. Furthermore, the expression levels and enzyme activities of HMGS, HMGR, FPPS, SQS and SE were significantly upregulated by adding linolenic acid at specific period. ConclusionAll mechanism explorations indicated that the effects of exogenous linolenic acid on triterpenoids production were tightly correlated with substrate supply, change of cell membrane and metabolic regulation of triterpenoids biosynthetic pathway.Graphical abstract [Display omitted]

Staged suppression of microglial autophagy facilitates regeneration in CNS demyelination by enhancing the production of linoleic acid

Microglia play a critical role in the clearance of myelin debris, thereby ensuring functional recovery from neural injury. Here, using mouse model of demyelination following two-point LPC injection, we show that the microglial autophagic-lysosomal pathway becomes overactivated in response to severe demyelination, leading to lipid droplet accumulation and a dysfunctional and pro-inflammatory microglial state, and finally failed myelin debris clearance and spatial learning deficits. Data from genetic approaches and pharmacological modulations, via microglial Atg5 deficient mice and intraventricular BAF A1 administration, respectively, demonstrate that staged suppression of excessive autophagic-lysosomal activation in microglia, but not sustained inhibition, results in better myelin debris degradation and exerts protective effects against demyelination. Combined multi-omics results in vitro further showed that enhanced lipid metabolism, especially the activation of the linoleic acid pathway, underlies this protective effect. Supplementation with conjugated linoleic acid (CLA), both in vivo and in vitro, could mimic these effects, including attenuating inflammation and restoring microglial pro-regenerative properties, finally resulting in better recovery from demyelination injuries and improved spatial learning function, by activating the peroxisome proliferator-activated receptor (PPAR-γ) pathway. Therefore, we propose that pharmacological inhibition targeting microglial autophagic-lysosomal overactivation or supplementation with CLA could represent a potential therapeutic strategy in demyelinated disorders.

Antiproliferative Fatty Acids Isolated from the Polypore Fungus Onnia tomentosa.

Onnia tomentosa is a widespread root rot pathogen frequently found in coniferous forests in North America. In this study, the potential medicinal properties of this wild polypore mushroom collected from north-central British Columbia, Canada, were investigated. The ethanol extract from O. tomentosa was found to exhibit strong antiproliferative activity. Liquid-liquid extraction and bioactivity-guided fractionation, together with HPLC-MS/MS and 1D/2D NMR analyses of the ethanol extract of O. tomentosa, led to the identification of eight known linoleic oxygenated fatty acids (1.1-1.4 and 2-5), together with linoleic (6) and oleic acids (7). The autoxidation of linoleic acid upon isolation from a natural source and compound 5 as an autoxidation product of linoleic acid are reported here for the first time. GC-FID analysis of O. tomentosa, Fomitopsis officinalis, Echinodontium tinctorium, and Albatrellus flettii revealed linoleic, oleic, palmitic, and stearic acids as the major fatty acids. This study further showed that fatty acids were the major antiproliferative constituents in the ethanol extract from O. tomentosa. Linoleic acid and oleic acid had IC50 values of 50.3 and 90.4 µM against human cervical cancer cells (HeLa), respectively. The results from this study have implications regarding the future exploration of O. tomentosa as a possible edible and/or medicinal mushroom. It is also recommended that necessary caution be taken when isolating unstable fatty acids from natural sources and in interpreting the results.

Homologous and Heterologous Expression of Delta(12)-Desaturase in Mucor circinelloides Enhanced the Production of Linolenic Acid.

Linolenic acid (LA) is gaining more interest within the scientific community. This is because it has a potential medical role in reducing the risk of inflammation, carcinogenesis, atherosclerosis and diabetes and is a valuable nutraceutical for human health. The oleaginous fungus Mucor circinelloides produces a high lipid content (36%), including valuable polyunsaturated fatty acids (PUFAs). However, the critical step in which oleic acid (OA) is converted into LA is not efficient at supplying enough substrates for PUFA synthesis. Hence, we propose a method to increase LA production based on genetic engineering. The overexpression of the Δ12-desaturase gene from M. circinelloides and Mortierella alpina increased the LA content and improved the lipid accumulation (from 14.9% to 21.6% in the Δ12-desaturase gene of the M. circinelloides overexpressing strain (Mc-D12MC) and from 14.9% to 18.7% in the Δ12-desaturase gene of M. alpina overexpressing strain (Mc-D12MA)). Additionally, the up-regulated expression levels of these genes targeted the genes involved in NADPH production, implying that the elevated Δ12-desaturase gene may function as a critical regulator of NADPH and lipid synthesis in M. circinelloides. This study provides the first evidence to support the design of metabolic engineering related to LA and PUFA production in M. circinelloides for potential industrial applications.

Barley β-glucan for conjugated linoleic acid (CLA) production by Bifidobacterium animalis subsp. Lactis: Fatty acid variation and bacterial viability study

In the present study, production of two isomers (cis-9, trans-11 and trans-10, cis-12) of conjugated linoleic acid (CLA) by Bifidobacterium animalis subsp. Lactis BB12 was investigated in organic and conventional milk in the presence of barley derived β-glucan. Fatty acid profile, acidification profile, cell enumeration and lactose content were determined for fermented conventional and organic milk, before and after 30 h fermentation in 30 °C. Viscometery and sensory evaluations were also performed. The results showed higher counts of Bifidobacterium animalis subsp. Lactis BB12, and viscosity in organic milk. Also, organic fermented milk offered higher CLA as well as polyunsaturated fatty acids values and a lower level of saturated fatty acids in comparison to conventional fermented milk. Cis-9, trans-11 CLA, trans-10, cis-12 CLA and polyunsaturated fatty acids values, bacterial count and viscosity in organic milk containing β-glucan were 28%, 39%, 33%, one log CFU/mL and 59% higher than the samples without β-glucan, respectively. Although these results were obtained for conventional milk, the variation percentage in the organic milk was significantly more than the conventional milk. In addition, the total lactose content in organic and conventional milk containing β-glucan was 19% and 12% lower than the samples without prebiotic.