Amounts Of Neutral Lipids Research Articles

First assessment of leaf lipids and fatty acids as biomarkers of grapevine tolerance/susceptibility to Plasmopara viticola

Grapevine is susceptible to several diseases, being downy mildew, caused by Plasmopara viticola, among the most devastating. Control strategies include the application of pesticides every season through almost all the grapevine developmental stages, jeopardizing viticulture sustainability. Understanding resistance molecular processes is crucial to define alternative strategies and select disease resistance traits. Identifying markers that discriminate between tolerant and susceptible genotypes to P. viticola is an important step. It is shown that lipids and fatty acids (FA) play an important role in grapevine defence against downy mildew and in our previous works we have highlighted that susceptible and resistant grapevine genotypes present contrasting FA profiles even without infection. Here, the constitutive lipid and FA composition of four grapevine genotypes, with contrasting behaviour toward P. viticola was analysed. FA desaturases (FAD) gene expression was also analysed. The results indicate that the susceptible genotypes present higher content of plastidial lipids and unsaturated FA and higher expression levels of FAD genes, whereas tolerant genotypes have higher amounts of neutral lipids and phosphatidic acid as well as saturated FA. In this preliminary study, the concentration of monogalactosyldiacylglycerol and phosphatidylcholine was pinpointed as potential tolerance-associated biomarkers and both linoleic acid and plastidial lipids as susceptibility-associated biomarkers.

NEUTRAL LIPIDS AND HIGHER FATTY ACIDS IN REPRESENTATIVES OF THE GENUS ALLIUM L. OF THE KO-MI REPUBLIC FLORA

The study of the content of neutral lipids (NL) and higher fatty acids (HFA) in three species of the genus Allium from the flora of the Komi Republic: A. angulosum, A. schoenoprasum and A. strictum is carried out. The amount of neutral lipids in different parts of the studied plants averaged from 0.5 to 6.5% of the air-dry mass. Seeds of all kinds were distinguished by the greatest accumulation of NL (up to 10–13%). It is shown that the composition of the NL of the studied species consists mainly of fatty acid molecules with a chain length of C14 – C20 and an even number of carbon atoms. Their distribution by parts of the plant has common patterns for all three species. The main amount of saturated fatty acid in all parts of the plant is palmitic acid C16:0, the amount of which is 20.8–49.1% of the total acid content. Of unsaturated acids, linoleic acid (C18:2) dominates, the content of which lies in the range of 21.9–73.0%. Linolenic acid (C18:3) it accumulates in maximum amounts in the leaves, from 25.5 to 37.0%, while in other parts its content does not exceed 10%. The leaves are characterized by an organ-specific distribution of linoleic and linolenic acids, the quantitative ratio of which is close to 1 : 1. Linoleic acid is the main content in seed oil (from 69.3 to 73.0%), and the total amount of unsaturated acids exceeds 92%. The study of seasonal dynamics showed that the content of NL in the leaves and bulbs of A. angulosum and A. stricrum is maximal in the regrowth phase and minimal in the flowering phase. In luke A. schoenoprasum the largest amount of NL was found in the budding phase, in the fruiting phase it dropped to the minimum values.

Fatty acid profiles in various lipid fractions in the female epidermis. Does the body site and age matter?

The epidermis forms the barrier between an organism and its external environment. Although one of the major functional elements of the epidermis is the lipid-enriched extracellular matrix, containing mainly ceramides, cholesterol (CHOL) and free fatty acids, the data are limited regarding the lipid profile in the epidermis. The aim of the study was to determine the whole profile of fatty acids (FAs) in the epidermis and to examine any dependence according to the age of the subject and the site on the epidermis. Epidermis extracts obtained from 10 adults and 6 children were analyzed by gas chromatography-mass spectrometry. In total, 74 FAs in the human epidermis were identified. We observed the highest amounts of neutral lipids (including CHOL) compared to other lipid fractions in the epidermis, regardless of age. However, we detected an age-dependent content of the major lipid fractions, where the main difference was in the levels of polyunsaturated fatty acids. There were also differences in the lipid profile between various sites of the body, e.g. samples from the breast and abdomen were enriched with very long-chain fatty acids compared to the limb. Our research provides novel data concerning the lipid profile in the epidermis, gives further insight into skin biology and proves that the epidermis is a highly dynamic structure.

Efficient method for the determination of the neutral lipid content of oil-producing microalgae strains required for biodiesel

The continued use of petroleum-derived fuels is unsustainable, as these fuels contribute to the environmental accumulation of carbon dioxide. Renewable fuels are necessary for environmental and economic sustainability. Microalgae appear to be the source of renewable biofuel that can meet the global demand for transport fuels. Like plants, microalgae use sunlight to produce oils but they do so more efficiently than crop plants. Oil productivity of many microalgae greatly exceeds the oil productivity of the best producing oil crops. Using microalgae to produce biofuel does not occupy agricultural land will not compromise production of food and other products derived from crops.During the growth of microalgae, the quantitative and qualitative values of produced lipids are constantly changing. Therefore, a laboratory lipid determination method had to be developed. Among the various industrial lipid extraction and purification methods, we only dealt with methods that can also be used in the laboratory. Because only neutral lipid fraction can be used to produce biofuels, an optimized method had to be developed to separate and determine the amount of neutral lipids. Each step was optimized in terms of time, volume, amount of chemical, simplicity and accuracy, these were the main aspects so that the method could be used for a wide range of lipid content and composition. The developed microextraction method enables the examination of a small amount of sample (100 mg) in a small volume (5 mL), in that way many samples can be processed simultaneously. This method saves time, money and chemicals in the laboratory while improving the accuracy of the lipid content determination.

Deficiency of Acetyl-CoA Carboxylase Impairs Digestion, Lipid Synthesis, and Reproduction in the Kissing Bug Rhodnius prolixus.

Rhodnius prolixus is a hematophagous insect, vector of Chagas disease. After feeding, as blood is slowly digested, amino acids are used as substrates to fuel lipid synthesis, and adult females accumulate lipids in the fat body and produce eggs. In order to evaluate the importance of de novo fatty acid synthesis for this insect metabolism, we generated acetyl-CoA carboxylase (ACC) deficient insects. The knockdown (AccKD) females had delayed blood digestion and a shorter lifespan. Their fat bodies showed reduced de novo lipogenesis activity, did not accumulate triacylglycerol during the days after blood meal, and had smaller lipid droplets. At 10 days after feeding, there was a general decrease in the amounts of neutral lipids and phospholipids in the fat body. In the hemolymph, no difference was observed in lipid composition at 5 days after blood meal, but at day ten, there was an increase in hydrocarbon content and a decrease in phospholipids. Total protein concentration and amino acid composition were not affected. The AccKD females laid 60% fewer eggs than the control ones, and only 7% hatched (89% for control), although their total protein and triacylglycerol contents were not different. Scanning electron microscopy of the egg surface showed that chorion (eggshell) from the eggs laid by the AccKD insects had an altered ultrastructural pattern when compared to control ones. These results show that ACC has a central role in R. prolixus nutrient homeostasis, and its appropriate activity is important to digestion, lipid synthesis and storage, and reproductive success.

Characterization of the Nuclear Proteome of Chlamydomonas in Response to Salt Stress

Microalgae biomass is considered a promising alternative feedstock for biodiesel production due to its high productivity of neutral lipids, especially under abiotic stress conditions. Among the unicellular microalgae that show this characteristic, Chlamydomonas reinhardtii appears as one of the most important model species with increased lipid production under abiotic stress conditions. In this study, we show that C. reinhardtii cells cultivated under mixotrophic condition supplemented with 0.1 M of NaCl rapidly raise their intracellular amount of neutral lipids without a reduction in their cellular growth rate, representing a promising condition for biomass production toward bioenergy applications. The nuclear proteome of these cells was investigated, and we identified 323 proteins with an enrichment of almost 60% of nuclear proteins in the total dataset. We found 61 proteins differentially regulated upon salt treatment, including proteins annotated in functional categories related to translation and nucleosome assembly functions. Additionally, we identified transcription factor proteins (TFs) and analyzed their likely transcription factor-binding regulatory elements, identifying target genes related to lipid metabolism and kinase functions, indicating possible regulatory pathways of lipid biosynthesis. Together, these data can help understand regulatory nuclear mechanisms, leading to an increase in lipids in the first 24 h of salt stress.

Bioprospecting of Microalgae Isolated from the Adriatic Sea: Characterization of Biomass, Pigment, Lipid and Fatty Acid Composition, and Antioxidant and Antimicrobial Activity.

Marine microalgae and cyanobacteria are sources of diverse bioactive compounds with potential biotechnological applications in food, feed, nutraceutical, pharmaceutical, cosmetic and biofuel industries. In this study, five microalgae, Nitzschia sp. S5, Nanofrustulum shiloi D1, Picochlorum sp. D3, Tetraselmis sp. Z3 and Tetraselmis sp. C6, and the cyanobacterium Euhalothece sp. C1 were isolated from the Adriatic Sea and characterized regarding their growth kinetics, biomass composition and specific products content (fatty acids, pigments, antioxidants, neutral and polar lipids). The strain Picochlorum sp. D3, showing the highest specific growth rate (0.009 h−1), had biomass productivity of 33.98 ± 0.02 mg L−1 day−1. Proteins were the most abundant macromolecule in the biomass (32.83–57.94%, g g−1). Nanofrustulum shiloi D1 contained significant amounts of neutral lipids (68.36%), while the biomass of Picochlorum sp. D3, Tetraselmis sp. Z3, Tetraselmis sp. C6 and Euhalothece sp. C1 was rich in glycolipids and phospholipids (75%). The lipids of all studied microalgae predominantly contained unsaturated fatty acids. Carotenoids were the most abundant pigments with the highest content of lutein and neoxanthin in representatives of Chlorophyta and fucoxanthin in strains belonging to the Bacillariophyta. All microalgal extracts showed antioxidant activity and antimicrobial activity against Gram-negative E. coli and S. typhimurium and Gram-positive S. aureus.

Abstract 10915: Unappreciated Mechanisms of Fatty Acid Uptake in the Kidney: Fatty Acids Are Taken Up from Both Basolateral and Apical Side

Introduction: The kidney combusts a large amount of fatty acid (FA) for body fluid homeostasis. Despite the high demand for FA, however, little is known about the mechanisms of FA uptake. We aimed to determine how FAs are taken up by tubular epithelial cells. Methods and Results: Immunohistochemistry showed that CD36, known as an important FA transporter in the heart, was also expressed in the basolateral side of proximal tubule epithelial cells (PTECs). The uptake of 125 I-BMIPP, radio-labeled FA tracer, was significantly reduced in the kidney in CD36 knockout mice 1 min after its injection compared with wild-type mice, while the significant difference disappeared 30 min after the injection. In vivo imaging with two-photon microscopy revealed that BODIPY-C 12 , fluorescence-labeled FA tracer, was accumulated in the basolateral side (blood side) of PTECs shortly after its injection, which was followed by accumulation in the apical side (primary urine side), suggesting bidirectional FA uptake by PTECs. A large amount of neutral lipid was accumulated in the kidney when serum FA concentration was increased by accelerated lipolysis by administration of a β3 adrenergic receptor agonist. Immunofluorescence with cell-specific antibodies revealed that the cells with the most abundant lipid accumulation were PTECs, followed by tubular epithelial cells of the distal nephron. In addition, neutral lipid accumulation was enhanced even in the distal nephron when PTECs were injured with administrations of diphtheria toxin (DT) in mice overexpressing DT-receptor in a PTEC-specific manner. Importantly, the PTEC-injured mice exhibited marked albuminuria, suggesting disturbance of protein reabsorption. Despite marked albuminuria, however, urinary FA was not detected at all, suggesting complete FA reabsorption independently of albumin reabsorption in the kidney. Conclusions: Our results revealed the unique and prominent capability of proximal and distal tubular epithelial cells to take up FA from both blood (CD36-dependent) and primary urine (CD36-independent) and to store them as neutral lipids. We further suggest that the kidney acts not only as FA consuming tissue but also as FA keeping tissue to completely reabsorb FA from primary urine for unwasted energy use.

Lipidomic response of the entomopathogenic fungus Beauveria bassiana to pyrethroids

Pyrethroids are chemical insecticides that are widely used to control pests. Entomopathogenic fungi are considered environmentally safe alternatives to these compounds. Pyrethroids and entomopathogenic fungi not only co-exist in the environment but can also be applied together in pest control. They are often found in contact with each other, and thus, it seems important to understand their interactions at the cellular level. In this study, we analyzed whether pyrethroids could influence the phospholipid profile of Beauveria bassiana and whether membrane changes are one of the mechanisms by which these fungi adapt to unfavorable environmental conditions. The results of our study revealed that pyrethroids changed the phospholipid profile and increased the cell membrane permeability of B. bassiana, which enabled them to enter and accumulate within the fungal cells, resulting in oxidative stress. Pyrethroids influenced the amount of neutral lipids, caused a decrease in sodium content, and also temporarily lowered the level of the secondary metabolite oosporein in the studied fungi. These findings indicate that the effect of pyrethroids on entomopathogenic fungi may be more complex than originally thought and that lipidomic studies can aid in fully understanding the influence of these chemicals on the mentioned group of fungi.

Palmitic Acid Lipotoxicity in Microglia Cells Is Ameliorated by Unsaturated Fatty Acids.

Obesity and metabolic syndrome are associated with cognitive decline and dementia. Palmitic acid (PA) is increased in the cerebrospinal fluid of obese patients with cognitive impairment. This study was therefore designed to examine fatty acid (FA) lipotoxicity in BV2 microglia cells. We found that PA induced time- and dose-dependent decrease in cell viability and increase in cell death without affecting the cell cycle profile and that PA lipotoxicity did not depend on cell surface free fatty acid receptors but rather on FA uptake. Treatment with sulfosuccinimidyl oleate (SSO), an irreversible inhibitor of fatty acid translocase CD36, significantly inhibited FA uptake in BSA- and PA-treated cells and blocked PA-induced decrease in cell viability. Inhibition of ER stress or treatment with N-acetylcysteine was not able to rescue PA lipotoxicity. Our study also showed that unsaturated fatty acids (UFAs), such as linoleic acid (LA), oleic acid (OA), α-linolenic acid (ALA), and docosahexaenoic acid (DHA), were not lipotoxic but instead protected microglia against PA-induced decrease in cell viability. Co-treatment of PA with LA, OA, and DHA significantly inhibited FA uptake in PA-treated cells. All UFAs tested induced the incorporation of FAs into and the amount of neutral lipids, while PA did not significantly affect the amount of neutral lipids compared with BSA control.

Enhancement of Lipid Extraction from Soya Bean by Addition of Dimethyl Ether as Entrainer into Supercritical Carbon Dioxide.

Soya beans contain a variety of lipids, and it is important to selectively separate neutral lipids from other lipids. Supercritical carbon dioxide extraction has been used as an alternative to the selective separation of neutral lipids from soya beans, usually using non-polar hexane. However, supercritical carbon dioxide extraction has a high operating pressure of over 40 MPa. On the other hand, liquefied dimethyl ether extraction, which has attracted attention in recent years, requires an operating pressure of only 0.5 MPa, but there is concern about the possibility of an explosion during operation because it is a flammable liquefied gas. Therefore, this study aims to reduce the operating pressure by using a non-flammable solvent, supercritical carbon dioxide extraction mixed with liquefied dimethyl ether as an entrainer. The extraction rate and the amount of neutral lipids extracted increased with increasing amounts of added liquefied dimethyl ether. In the mixed solvent, the amount of neutral lipids extracted was higher at an operating pressure of 20 MPa than in pure supercritical carbon dioxide extraction at 40 MPa. The mixing of liquefied dimethyl ether with supercritical carbon dioxide allowed an improvement in the extraction of neutral lipids while remaining non-flammable.

Antiobesity effect of ethanolic extract of Ramulus mori in differentiated 3T3-L1 adipocytes and high-fat diet-induced obese mice.

The mulberry (Morus alba L.) is a plant that mainly grows in East Asian countries such as Korea and China and has been used as a folk remedy for improving inflammation, cancer, and diabetes. Ramulus mori, the twig of Morus alba L., is known as "sangzhi" or "ppongnamugazhi" in Korea and used as a traditional medicine. Moreover, its effective compounds show some health benefits such as cholesterol reduction and attenuation of acute colitis. As the number of obese people is increasing worldwide, the demand for diet drugs or products to treat obesity is also increasing. In this study, we investigated the antiobesity effect of the ethanolic extract of Ramulus mori (ERM) using differentiated 3T3-L1 adipocytes and a high-fat diet (HFD)-induced obese mouse model. The expression levels of genes and proteins related to adipogenesis, lipogenesis, and lipolysis were analyzed by quantitative real-time PCR (qPCR) and western blot, respectively. Oil red O staining was carried out to determine the amount of neutral lipids deposited in the liver. Compared with the ERM-untreated group, the ERM-treated groups exhibited reduced expression levels of genes involved in adipogenesis and lipogenesis in differentiated adipocytes and in HFD-induced obese mice, while the expression levels of genes involved in lipolysis increased. The administration of ERM to HFD-induced obese mice reduced the body weight, liver weight, and epididymal adipose tissue weight. Compared with the untreated HFD-induced obese mice, the ERM-treated mice exhibited decreased serum lipid levels. ERM treatment also reduced lipid accumulation in the liver, which was confirmed by oil red O staining. ERM has the potential to be an effective natural material for reducing obesity.

Characterization of the Lipid Components in <i>Desmodesmus</i> and <i>Scenedesmus</i> Strains: Lipid Content, Lipid Classes and Fatty Acid Profile

The lipid composition in terms of the amount of neutral lipids, free fatty acids and polar lipid content is of great importance to make full use possible of this fraction and to define the suitability of its application, either as a raw material for fuel production, nutraceutical purposes or feed. In addition to the fatty components present in the lipid extract, other components may be included, such as: carotenoids, pigments and sterols. The microalgae studied in this work, Scenedesmus sp. and Desmodesmus sp., were subjected to the same growth conditions and evaluated for lipid content, quantification and diversity of lipid components as well as its fatty acid profile. For lipid determination two extraction methods were compared: the J: Schmid-Bondzynski-Ratzlaff and Bligh & Dyer method. For Desmodesmus sp. 5.43% ± 0.41% and 9.18% ± 0.33% of lipids were obtained on an ash-free dry weight basis and for Scenedesmus sp. 12.46% ± 0.38% and 8.16% ± 0.42% of lipids were obtained on an ash-free dry weight basis using for both methods J: Schmid-Bondzynski-Ratzlaff and Bligh & Dyer, respectively. For the identification of the main lipid components present in the extracts, the Thin layer chromatography (TLC) technique was used. This made it possible, using a simple and inexpensive method, to identify the compounds extracted by different extraction methods, that is, it was possible to verify the selectivity of the different extraction methods. In addition, it has been shown that using these methods, widely described in the literature as methods of extracting lipids in practice, extracts a wide diversity of compounds. The major lipid class for both microalgae was fatty acids with amounts between 23.62% - 38.02%. The triglycerides percentage in biomasses without chemical treatment did not exceed 18.26%. In the lipid extract obtained with Bligh & Dyer, the microalgae Desmodesmus sp. presented 55.26% of unsaponifiable material, higher than the amount present using the same extraction method for Scenedesmus sp. 49.06%. Among the main unsaponifiables identified are hydrocarbons (carotenes) and sterols esters. The acid treatment of biomass, method J: Schmid-Bondzynski-Ratzlaff, showed selectivity of 72.84% and 76.66% for obtaining fatty material from the microalgae Desmodesmus sp. and Scenedesmus sp., respectively. The results showed that depending on the method used for extraction, the lipid fraction will be different in relation to the percentage of fatty components.

Lactobacillus salivarius BGHO1 and Lactobacillus reuteri BGGO6-55 modify nutritive profile of Artemia franciscana nauplii in a strain ratio, dose and application timing-dependent manner

This study aimed to analyze an impact of Lactobacillus salivarius BGHO1 and Lactobacillus reuteri BGGO6-55 supplemented to Artemia franciscana cultivation medium on biochemical profile of hatched nauplii. Impacts of different BGHO1:BGGO6-55 ratios (75:25, 50:50 and 25:75) and their total concentrations (250 and 500 g/kg of Artemia cysts) at different timings of bacteria application (pre- and post-hatching) were examined. The effects were evaluated by quantification of naupliar peptide, soluble protein, phospho-, neutral and unsaturated lipid content. Uni and multi-factorial analysis of variance (ANOVA) were used to estimate the effects of treatments relative to control and to model factor interactions, respectively Statistical analysis indicated that post-hatching application of 75:25 strain ratio at high dose was associated with an increase of neutral lipid amount. Furthermore, factor interaction profiling identified positive correlation of lactobacilli concentration with the level of free amino acids/short peptides, phospho-, neutral and unsaturated lipids, but only at 50:50 strain ratio combination. Application of lower lactobacilli dose at 75:25 strain ratio caused an increase of soluble protein and phospholipid amount. Hypothetically, graded response of Artemia nauplii to lactobacilli supplementation was induced with different BGHO1 doses. It assumedly ranged from stress-response protein synthesis at lower doses to membrane permeability alterations and triglyceride-mediated defense mechanism activation at higher BGHO1 doses. In contrast to lactobacilli supplementation after Artemia hatching, pre-hatching application of lactobacilli was not associated with an increase of Artemia nutritive profile, though again there was a positive association of lactobacilli concentration with nutrient amount. This implicates interference of lactobacilli with the hatching process. Results presented here facilitate the design of future studies aiming to modify Artemia nutritive profile in accordance with nutritional demands of cultivated fish species.

Lipid Class and Fatty Acid Compositions of Dried Sea Cucumber Apostichopus japonicus

Introduction: Sea cucumber, Apostichopus japonicus, is becoming popular around the world due to its nutritional and medicinal properties. There are still no detailed chemical studies of the lipid class, glycolipids compositions of sea cucumber. Methods: This study was conducted to determine the lipid class and glycolipid compositions of dried sea cucumber, A. japonicus, and analyze fatty acid compositions of Monogalactosyl Diglycerides (MGDG), Steryl Glycosides (SG) and Sulfoquinovosyl Diglycerides (SQDG). Total lipids of sea cucumber were extracted by Bligh and Dyer method and Sep-Pak Silica plus long cartridge, and Thin Layer Chromatography (TLC) silica gel G-60 F254 was used for the separation of different lipid classes and glycolipid compositions. The composition of fatty acids was analyzed by GC. Results & Conclusion: The level of total lipids in the dried sea cucumber, Apostichopus japonicus, was 4 ± 1% of dry weight (w/w) and the amount of neutral lipids, glycolipids and phospholipids was 31 ± 1%, 29 ± 1% and 40 ± 1% of the total lipids (w/w), respectively. MGDG, SG and SQDG were the major glycolipids, and the contents were 37.5 ± 0.3%, 33.8 ± 0.5% and 23.6 ± 0.7% of the total glycolipids (w/w), respectively and significantly higher than other glycolipids (p < 0.05). SQDG contained much higher Arachidonic Acid (AA), Eicosapentaenoic Acid (EPA) and MGDG contained higher Docosahexaenoic Acid (DHA) compared with SG (p < 0.05). Further investigation is required to understand the positional distribution of fatty acids and molecular species in MGDG, SG and SQDG in detail.

Impact of Nutrient Availability on Tertiary Wastewater Treatment by Chlorella vulgaris.

Algae can use excessive nutrients from wastewater effluent to generate beneficial products such as biofuels. However, fluctuation of wastewater characteristics could hinder the implementation of tertiary algal treatment. This study aims to identify the impact of nutrient availability on Chlorella vulgaris's ability to remove nitrogen and phosphorus from wastewater, and its potential as a biofuel feedstock. Experiments using synthetic wastewater with varying concentrations of nitrate and phosphate showed C. vulgaris continued to remove either nutrient when the other was exhausted. Nitrogen starvation led the algae to accumulate the highest amount of neutral lipid; however, the exhaustion of phosphorus did not produce such impact. Synergistic effect was also observed between C. vulgaris and indigenous microorganisms in nutrient removal from real wastewater effluent. The results showed C. vulgaris can survive in a range of nutrient-limiting conditions, making tertiary algal treatment applicable following various secondary treatment regimes.

Complex lipid metabolic remodeling is required for efficient hepatitis C virus replication

The hepatitis C virus (HCV) life cycle is tightly linked to the host cell lipid metabolism with the endoplasmic reticulum–derived membranous web harboring viral RNA replication complexes and lipid droplets as virion assembly sites. To investigate HCV-induced changes in the lipid composition, we performed quantitative shotgun lipidomic studies of whole cell extracts and subcellular compartments. Our results indicate that HCV infection reduces the ratio of neutral to membrane lipids. While the amount of neutral lipids and lipid droplet morphology were unchanged, membrane lipids, especially cholesterol and phospholipids, accumulated in the microsomal fraction in HCV-infected cells. In addition, HCV-infected cells had a higher relative abundance of phosphatidylcholines and triglycerides with longer fatty acyl chains and a strikingly increased utilization of C18 fatty acids, most prominently oleic acid (FA [18:1]). Accordingly, depletion of fatty acid elongases and desaturases impaired HCV replication. Moreover, the analysis of free fatty acids revealed increased levels of polyunsaturated fatty acids (PUFAs) caused by HCV infection. Interestingly, inhibition of the PUFA synthesis pathway via knockdown of the rate-limiting Δ6-desaturase enzyme or by treatment with a high dose of a small-molecule inhibitor impaired viral progeny production, indicating that elevated PUFAs are needed for virion morphogenesis. In contrast, pretreatment with low inhibitor concentrations promoted HCV translation and/or early RNA replication. Taken together our results demonstrate the complex remodeling of the host cell lipid metabolism induced by HCV to enhance both virus replication and progeny production.

Analysis of population structures of the microalga Acutodesmus obliquus during lipid production using multi-dimensional single-cell analysis

Microalgae bear a great potential to produce lipids for biodiesel, feed, or even food applications. To understand the still not well-known single-cell dynamics during lipid production in microalgae, a novel single-cell analytical technology was applied to study a well-established model experiment. Multidimensional single-cell dynamics were investigated with a non-supervised image analysis technique that utilizes data from epi-fluorescence microscopy. Reliability of this technique was successfully proven via reference analysis. The technique developed was used to determine cell size, chlorophyll amount, neutral lipid amount, and deriving properties on a single-cellular level in cultures of the biotechnologically promising alga Acutodesmus obliquus. The results illustrated a high correlation between cell size and chlorophyll amount, but a very low and dynamic correlation between cell size, lipid amount, and lipid density. During growth conditions under nitrogen starvation, cells with low chlorophyll content tend to start the lipid production first and the cell suspension differentiated in two subpopulations with significantly different lipid contents. Such quantitative characterization of single-cell dynamics of lipid synthesizing algae was done for the first time and the potential of such simple technology is highly relevant to other biotechnological applications and to deeper investigate the process of microalgal lipid accumulation.

Rosemary (Rosmarinus officinalis) oil: composition and functionality of the cold-pressed extract

The aim of this work was to investigate cold-pressed rosemary oil (RO) for its lipid classes, subclasses, fatty acid composition, tocochromanols and total phenolics amount. Antiradical activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH•) and galvinoxyl radicals, antioxidant activity, as measured by the Rancimat test, as well as antimicrobial activity against food-borne bacteria, and dermatophytic fungi of RO were evaluated. In RO, the amount of neutral lipids was highest (ca. 86%), followed by phospholipids (0.92%) and glycolipids (0.88%). The percentages of monounsaturated, polyunsaturated, and saturated fatty acids were 41.7, 42.3, and 15.8%, respectively. Linoleic acid (41.7%) and oleic acid (41.2%) were the major fatty acids while linolenic acid accounted for 1.3% of total fatty acids. The following tocochromanols were detected: α-, β-, γ- and δ-tocopherols, which accounted for 291, 22, 1145, and 41 mg/100 g oil, respectively, as well as α-, β-, γ- and δ-tocotrienols, which accounted for 18, 12, 29, and 158 mg/100 g oil, respectively. RO also contained high levels of phenolic compounds (7.2 mg GAE/g). After 60 min of reaction with free radicals, 67% of DPPH• and 55% of galvinoxyl radicals were quenched by RO. Rancimat test showed that blending RO with sunflower oil increased the induction period (IP) for blends. The IP of the RO: sunflower oil blend (1:9, v/v) was 390 min, and RO: sunflower oil blend (2:8, v/v) was longer (540 min). RO exhibited high antimicrobial potential against food-borne pathogenic bacteria (E. coli, S. enteritidis, and L. monocytogenes) and high antifungal potential against dermatophyte fungi (T. mentagrophytes, and T. rubrum). RO had unique high level of γ-tocopherol, which is a scavenger of reactive nitrogen species making it a promising material in the food, cosmetic and pharmaceutical applications.

Cultivation of the microalga Neochloris oleoabundans for biofuels production and other industrial applications (a review)

Microalgae cultivation for biofuels production and other applications has gained considerable interest recently. Despite their simple structures, microalgae can accumulate significant amounts of neutral lipids per dry cell weight compared to other energy crops. Neochloris oleoabundans is a promising microalga known for its high lipid content and biomass growth rate compared to other species cultivated for biofuels synthesis; therefore, it is considered as a suitable candidate for biodiesel synthesis. This review paper covers several key aspects associated with the cultivation and applications of the microalga N. oleoabundans. Biomass composition, factors affecting the growth, and biomass and lipid productivities of this species were addressed. In addition, different growth conditions as well as alternative readily available nutrient media to support the growth of N. oleoabundans were presented in this review.