scholarly journals Differences in Membrane Fluidity and Fatty Acid Composition between Phenotypic Variants of Streptococcus pneumoniae

2004 ◽  
Vol 186 (14) ◽  
pp. 4638-4644 ◽  
Author(s):  
Barak Aricha ◽  
Itzhak Fishov ◽  
Zvi Cohen ◽  
Noga Sikron ◽  
Stella Pesakhov ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Streptococcus Pneumoniae ◽  
Membrane Fluidity ◽  
Acid Composition ◽  
Rate Constant ◽  
Unsaturated Fatty Acids ◽  
Phase Variation ◽  
Bacterial Cells

ABSTRACT Phase variation in the colonial opacity of Streptococcus pneumoniae has been implicated as a factor in the pathogenesis of pneumococcal disease. This study examined the relationship between membrane characteristics and colony morphology in a few selected opaque-transparent couples of S. pneumoniae strains carrying different capsular types. Membrane fluidity was determined on the basis of intermolecular excimerization of pyrene and fluorescence polarization of 1,6-diphenyl 1,3,5-hexatriene (DPH). A significant decrease, 16 to 26% (P ≤ 0.05), in the excimerization rate constant of the opaque variants compared with that of the transparent variants was observed, indicating higher microviscosity of the membrane of bacterial cells in the opaque variants. Liposomes prepared from phospholipids of the opaque phenotype showed an even greater decrease, 27 to 38% (P ≤ 0.05), in the pyrene excimerization rate constant compared with that of liposomes prepared from phospholipids of bacteria with the transparent phenotype. These findings agree with the results obtained with DPH fluorescence anisotropy, which showed a 9 to 21% increase (P ≤ 0.001) in the opaque variants compared with the transparent variants. Membrane fatty acid composition, determined by gas chromatography, revealed that the two variants carry the same types of fatty acids but in different proportions. The trend of modification points to the presence of a lower degree of unsaturated fatty acids in the opaque variants compared with their transparent counterparts. The data presented here show a distinct correlation between phase variation and membrane fluidity in S. pneumoniae. The changes in membrane fluidity most probably stem from the observed differences in fatty acid composition.

scholarly journals The influence of fatty acid composition on the kinetics of the vegetable oil methanolysis reaction

2021 ◽  
Vol 10 (2) ◽  
pp. 24-31
Author(s):  
Milan Kostić ◽  
Olivera Stamenković ◽  
Vlada Veljković
Keyword(s):  
Fatty Acids ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Acid Composition ◽  
Rate Constant ◽  
Reaction Rate ◽  
Unsaturated Fatty Acids ◽  
Reaction Rate Constant ◽  
Conversion Degree ◽  
Kinetics Of

The base-catalyzed methanolysis of roadside pennycress, olive, melon, grapeseed, hempseed, sunflower, and plum kernel oils was performed in the presence of KOH (1% to the oil weight) at the temperature of 60° C and the methanol/oil molar ratio of 6:1. The aim of this work was to reveal the influence of the fatty acid composition of the oils on the kinetics of these methanolysis reactions. The irreversible pseudo-first-order reaction was used for modeling the kinetics of the methanolysis reactions, and the reaction rate constant was correlated with the content of unsaturated fatty acids in the oil. The value of the reaction rate constant increases linearly with increasing the unsaturated fatty acids content in the oil. The applicability and reliability of the model were confirmed by high values of the coefficient of determination and low values of the mean relative percentage deviation between the calculated and experimental triacylglycerols conversion degree.

scholarly journals Growth-Environment Dependent Modulation ofStaphylococcus aureusBranched-Chain to Straight-Chain Fatty Acid Ratio and Incorporation of Unsaturated Fatty Acids

2016 ◽  
Author(s):  
Suranjana Sen ◽  
Seth R. Johnson ◽  
Yang Song ◽  
Sirisha Sirobhushanam ◽  
Ryan Tefft ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Membrane Fluidity ◽  
Acid Composition ◽  
Unsaturated Fatty Acids ◽  
Cell Physiology ◽  
Biophysical Properties ◽  
Straight Chain ◽  
Chain Fatty Acids

AbstractThe fatty acid composition of membrane glycerolipids is a major determinant ofStaphylococcus aureusmembrane biophysical properties that impacts key factors in cell physiology including susceptibility to membrane active antimicrobials, pathogenesis, and response to environmental stress. The fatty acids ofS. aureusare considered to be a mixture of branched-chain fatty acids (BCFAs), which increase membrane fluidity, and straight-chain fatty acids (SCFAs) that decrease it. The balance of BCFAs and SCFAs in strains USA300 and SH1000 was affected considerably by differences in the conventional laboratory medium in which the strains were grown with media such as Mueller-Hinton broth and Luria broth resulting in high BCFAs and low SCFAs, whereas growth in Tryptic Soy Broth and Brain-Heart Infusion broth led to reduction in BCFAs and an increase in SCFAs. Straight-chain unsaturated fatty acids (SCUFAs) were not detected. However, when the organism was grownex vivoin serum, the fatty acid composition was radically different with SCUFAs, which increase membrane fluidity, making up a substantial proportion of the total (<25%) with SCFAs (>37%) and BCFAs (>36%) making up the rest. Staphyloxanthin, an additional major membrane lipid component unique toS. aureus, tended to be greater in content in cells with high BCFAs or SCUFAs. Cells with high staphyloxanthin content had a lower membrane fluidity that was attributed to increased production of staphyloxanthin.S. aureussaves energy and carbon by utilizing host fatty acids for part of its total fatty acids when growing in serum. The fatty acid composition ofin vitrogrownS. aureusis likely to be a poor reflection of the fatty acid composition and biophysical properties of the membrane when the organism is growing in an infection in view of the role of SCUFAs in staphylococcal membrane composition and virulence.Funding:This work was funded in part by grant 1R15AI099977 to Brian Wilkinson and Craig Gatto and grant 1R15GM61583 to Craig Gatto from the National Institutes of Health

scholarly journals DETERMINATION OF CHEMICAL PROPERTIES, COMPOSITION OF FATTY ACID, CAROTENOIDS AND TOCOPHEROLS OF DEGUMMED AND NEUTRALIZED RED FRUIT (Pandanus conoideus) OIL

2020 ◽  
Vol 82 (6) ◽  
pp. 71-78
Author(s):  
Zita Letviany Sarungallo ◽  
Budi Santoso ◽  
Risma Uli Situngkir ◽  
Mathelda Kurniaty Roreng ◽  
Meike Meilan Lisangan
Keyword(s):  
Fatty Acids ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Water Content ◽  
Acid Composition ◽  
Unsaturated Fatty Acids ◽  
Chemical Properties ◽  
Carotenoid Content ◽  
Fruit Oil ◽  
Β Carotene

Refining of crude red fruit oil (CRFO) through the degumming and neutralization steps intended to produce oil free of impurities (non triglycerides) such as phospholipids, proteins, residues and carbohydrates, and also reducing the amount of free fatty acids (FFA). This study aims to determine the effect of red fruit oil purification through degumming and neutralization stages on chemical properties, fatty acid composition, carotenoid content and tocopherol of red fruit oil (RFO). The results showed that degumming of CRFO did not affect the decrease in water content, FFA levels, peroxide numbers, iodine values, carotenoids and tocopherols content; but decrease in levels of phosphorus, β-carotene and α-tocopherol. Neutralization of degummed-RFO (DRFO) did not affect the decrease in water content, iodine value, carotenoid, tocopherol and α-tocopherol; but the FFA levels, peroxide number, phosphorus and β-carotene levels decreased significantly. The fatty acid composition of RFO was dominated by unsaturated fatty acids (± 75%), which increases through degumming and neutralization stages. β-carotene is more sensitive than α-tocopherol during refining process of crude oil, but in general, this process can improve the RFO quality.

scholarly journals Chemical Properties and Fatty Acid Composition of Palado Seed Oil (Aglaia sp) Extracted Using Chloroform Solvent

2021 ◽  
Vol 18 (4) ◽  
Author(s):  
Syamsul RAHMAN ◽  
Salengke Salengke ◽  
Abu Bakar TAWALI ◽  
Meta MAHENDRADATTA
Keyword(s):  
Fatty Acids ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Acid Composition ◽  
Seed Oil ◽  
Unsaturated Fatty Acids ◽  
Saturated Fatty Acids ◽  
Chemical Properties ◽  
Raw Material ◽  
Food Ingredients

Palado (Aglaia sp) is a plant that grows wild in the forest around Mamuju regency of West Sulawesi, Indonesia. This plant is locally known as palado. Palado seeds (Aglaia sp) can be used as a source of vegetable oil because it contains approximately 14.75 % oil, and it has the potential to be used as food ingredients or as raw material for oil production. The purpose of this study was to determine the chemical properties and the composition of fatty acids contained in palado seed oil (Aglaia sp). The employed method involved the use of palado fruit that had been processed to be palado seed and undergoing flouring process. Palado flour was produced by the extraction process by using chloroform solvent with the soxhlet method. The characteristics of the chemical properties in the oil produced were analyzed by using a standard method, including iodine, saponification, and acid values. The analysis of fatty acid composition was conducted by using gas chromatography. The results showed that palado oil extracted with hexane had an iodine value of 15.38 mg/g, saponification value of 190.01 mg KOH/g, and acids value of 1.961 mg KOH/g. The fatty acid composition of the palado seed oil consisted of saturated fatty acids (41.601 %), which included palmitic acid (41.062 %), myristic acid (0.539 %), and unsaturated fatty acids (45.949 %), which included mono-unsaturated fatty acids (MUFA) such as (22.929 %), oleic acid and poly-unsaturated fatty acids (PUFA), which was linoleic acid (23.020 %).

FATTY ACID COMPOSITION OF SERUM LIPIDS IN HYPER- AND HYPOTHYROIDISM

1972 ◽  
Vol 71 (1) ◽  
pp. 62-72 ◽  
Author(s):  
Knut Kirkeby
Keyword(s):  
Fatty Acids ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Linoleic Acid ◽  
Acid Composition ◽  
Serum Lipids ◽  
Unsaturated Fatty Acids ◽  
Eicosatrienoic Acid ◽  
High Linoleic Acid ◽  
Absolute Concentrations

ABSTRACT The fatty acid composition of cholesterol esters, phospholipids, and triglycerides of the serum has been studied in groups of hyperthyroid and hypothyroid women and also in control material matched for age. In hyperthyroidism, a decrease in the proportions of linoleic acid and an increase in the proportions of some saturated and mono-unsaturated fatty acids were observed. When absolute concentrations were considered, it appeared that the decrease in linoleic acid was almost equivalent to the entire decrease in total fatty acids in the serum of the hyperthyroid patients. In hypothyroidism no changes were noted in the proportions of linoleic, saturated and mono-unsaturated fatty acids, and the absolute concentrations reflected the general increase in serum lipids. It is believed that these findings may be explained by the changes in lipid turnover which are known to occur in disturbances of thyroid function. In hyperthyroidism, they lead to a linoleic acid deficiency, while a sparing effect must be operating in hypothyroidism. The finding of relatively high linoleic acid values combined with hyperlipaemia in hypothyroidism seems to be characteristic of the condition, since other types of hyperlipaemia are almost invariably combined with low percentages of linoleic acid. Results regarding arachidonic and eicosatrienoic acid are consistent with increased synthesis in hyperthyroidism, and decreased synthesis in hypothyroidism.

scholarly journals Stomata and Xylem Vessels Traits Improved by Melatonin Application Contribute to Enhancing Salt Tolerance and Fatty Acid Composition of Brassica napus L. Plants

Agronomy ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1186 ◽  
Author(s):  
Ibrahim A. A. Mohamed ◽  
Nesma Shalby ◽  
Ali M. A. El-Badri ◽  
Muhammad Hamzah Saleem ◽  
Mohammad Nauman Khan ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Oxidative Damage ◽  
Acid Composition ◽  
Salinity Stress ◽  
Unsaturated Fatty Acids ◽  
Oil Quality ◽  
Growth And Yield

Salinity stress is a limiting factor for the growth and yield quality of rapeseed. The potentiality of melatonin (MT; 0, 25, 50, and 100 µM) application as a seed priming agent in mediating K+/Na+ homeostasis and preventing the salinity stress mediated oxidative damage and photosynthetic inhibition was studied in two rapeseed cultivars. We found that 50 µM MT treatment imparted a very prominent impact on growth, metabolism of antioxidants, photosynthesis, osmolytes, secondary metabolites, yield, and fatty acids composition. Days required for appearance of first flower and 50% flowering were decreased by MT application. Exogenous MT treatment effectively decreased the oxidative damage by significantly declining the generation of superoxide and hydrogen peroxide under saline and non-saline conditions, as reflected in lowered lipid peroxidation, heightened membrane stability, and up-regulation of antioxidant enzymes (catalase, superoxide dismutase, and ascorbate peroxidase). Furthermore, MT application enhanced the chlorophyll content, photosynthetic rate, relative water content, K+/Na+ homeostasis, soluble sugars, and proline content. Moreover, MT application obviously improved the oil quality of rapeseed cultivars by reducing glucosinolates, saturated fatty acids (palmitic and arachidic acids), and enhancing unsaturated fatty acids (linolenic and oleic acids except erucic acid were reduced). Yield related-traits such as silique traits, seed yield per plant, 1000 seeds weight, seed oil content, and yield biomass traits were enhanced by MT application. The anatomical analysis of leaf and stem showed that stomatal and xylem vessels traits are associated with sodium chloride tolerance, yield, and seed fatty acid composition. These results suggest the supportive role of MT on the quality and quantity of rapeseed oil yield.

Selenate and selenite affect ruminal metabolism of C18 unsaturated fatty acids and fatty acid composition of lamb tissues

2020 ◽  
Vol 241 ◽  
pp. 104249
Author(s):  
Małgorzata Białek ◽  
Marian Czauderna ◽  
Wiesław Przybylski ◽  
Danuta Jaworska
Keyword(s):  
Fatty Acids ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Acid Composition ◽  
Unsaturated Fatty Acids

Regulation Of The Fatty Acid Composition Of Platelet Phospholipids

1981 ◽  
Author(s):  
M L McKean ◽  
J B Smith ◽  
M J Silver
Keyword(s):  
Fatty Acids ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Acid Composition ◽  
Unsaturated Fatty Acids ◽  
De Novo ◽  
Membrane Phospholipids ◽  
De Novo Biosynthesis ◽  
Coa Transferase

The fatty acid composition of cell membrane phospholipids does not remain constant after de novo biosynthesis, but undergoes continual remodelling. One of the major routes for remodelling probably includes the deacylation-reacylation steps of the Lands Pathway. This has been shown to be important for the incorporation of long chain, polyunsaturated fatty acids into phospholipids by liver and brain. An understanding of the mechanisms involved in these processes in platelets is especially important in light of the large stores of arachidonic acid (AA) in platelet phospholipids and the role of AA in hemostasis and thrombosis. Previous results from this laboratory have shown that the turnover of radioactive AA, 8,11,14-eicosatrienoic and 5,8,11,14,17-eicosapentaenoic acids in the phospholipids of resting platelets is more rapid than the turnover of radioactive C16 and C18 saturated and unsaturated fatty acids. However, little is known about how fatty acids, especially AA and its homologues, are incorporated into platelet phospholipids during de novo biosynthesis or how they are exchanged during remodelling.At least three enzymes are involved in the deacylation- reacylation of phospholipids: phospholipase A2; acyl CoA synthetase; and acyl CoA transferase. We have studied acyl CoA transferase and have found considerable activity in human platelet membranes. Experiments are in progress to determine the substrate specificity and other properties of this enzyme.

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