Concentrations Of Major Fatty Acids Research Articles

Alleviation of reactive oxygen species enhances PUFA accumulation in Schizochytrium sp. through regulating genes involved in lipid metabolism

The unicellular heterotrophic thraustochytrids are attractive candidates for commercial polyunsaturated fatty acids (PUFA) production. However, the reactive oxygen species (ROS) generated in their aerobic fermentation process often limits their PUFA titer. Yet, the specific mechanisms of ROS involvement in the crosstalk between oxidative stress and intracellular lipid synthesis remain poorly described. Metabolic engineering to improve the PUFA yield in thraustochytrids without compromising growth is an important aspect of economic feasibility. To fill this gap, we overexpressed the antioxidative gene superoxide dismutase (SOD1) by integrating it into the genome of thraustochytrid Schizochytrium sp. PKU#Mn4 using a novel genetic transformation system. This study reports the ROS alleviation, enhanced PUFA production and transcriptome changes resulting from the SOD1 overexpression. SOD1 activity in the recombinant improved by 5.2–71.6% along with 7.8–38.5% decline in ROS during the fermentation process. Interestingly, the total antioxidant capacity in the recombinant remained higher than wild-type and above zero in the entire process. Although lipid profile was similar to that of wild-type, the concentrations of major fatty acids in the recombinant were significantly (p ≤ 0.05) higher. The PUFA titer increased up to 1232 ± 41 mg/L, which was 32.9% higher (p ≤ 0.001) than the wild type. Transcriptome analysis revealed strong downregulation of genes potentially involved in β-oxidation of fatty acids in peroxisome and upregulation of genes catalyzing lipid biosynthesis. Our results enrich the knowledge on stress-induced PUFA biosynthesis and the putative role of ROS in the regulation of lipid metabolism in oleaginous thraustochytrids. This study provides a new and alternate strategy for cost-effective industrial fermentation of PUFA.

The effect of anabolic implants on intramuscular lipid deposition in finished beef cattle

Two experiments were conducted to determine the effects of anabolic implants on performance, changes in ultrasound measurements, carcass quality, cellularity of i.m. and s.c. adipose depots, and mRNA expression of acetyl CoA carboxylase (ACC), stearoyl CoA desaturase (SCD), and lipoprotein lipase (LPL) in i.m. adipose tissue of finished beef cattle. Angus heifers (experiment 1: n = 10; 411 kg of BW) and steers (experiment 2: n = 18; 279 kg of BW) were randomly allotted as control (C) or implanted with Synovex-Plus (SP) at d 0 and midway through the finishing period. The cattle were fed a high-concentrate diet and were weighed at approximately 28-d intervals. Heifers and steers were finished for 108 and 133 d, respectively. At slaughter, a section of the LM (sixth to ninth rib) was removed, and i.m. adipose tissue was dissected for mRNA analysis. Subcutaneous and i.m. adipose tissues also were collected for determination of cellularity. At 48 h postmortem, carcass data were collected, and a steak (12th rib) was removed for analysis of lipid and fatty acid composition. Body weight did not differ (P > 0.10) between treatments until after reimplanting of the heifers (d 55) or steers (d 73). Average daily gain was 36 and 16% faster (P < or = 0.01) for implanted heifers and steers, respectively, compared with their control counterparts. Implanting resulted in larger (P < or = 0.10) HCW and LM area for heifers and steers. However, implanting did not affect (P > 0.10) dressing percent, fat thickness, percentage of KPH, yield grade, or marbling score. Intramuscular lipid content and concentrations of major fatty acids did not differ (P > 0.10) between treatments. Percentage of SC adipocytes was greater at larger diameters ( > 150 microm), whereas the majority of i.m. adipocytes were at small to middle diameters (50 to 150 microm). The number of i.m. adipocytes per gram of tissue was greater (P < 0.05) for SP than C and also were greater (P < 0.05) than the number of s.c. adipocytes in SP heifers. In experiment 2, adipocytes per gram of tissue tended to be greater (P = 0.07) for SP than C and were greater (P < 0.01) for i.m. than s.c. In experiment 1, average cell diameter and volume did not differ (P > 0.10) between treatments and tissues, but in experiment 2 both cellularity traits were greater (P < 0.01) for s.c. than for i.m.. Implanting did not alter mRNA expression of ACC, SCD, or LPL in i.m. adipose tissue. This study shows that anabolic implants do not appear to have direct effects on i.m. lipid deposition.

Effects of artificial ultraviolet‐B radiation on growth and fatty acid composition of duckweed (Lemna minor)

Summary1. Duckweed (Lemna minor), collected either in summer or early fall was exposed under laboratory conditions to control (photosynthetically active and UV‐A radiation) or experimental (control plus UV‐B radiation) conditions.2. Growth and survival were determined by counting the number of green, and brown/white fronds following 1–5 or 11 days of irradiation. Growth of duckweed was impaired by exposure to UV‐B radiation in the fall experiment but not in the summer.3. Fatty acid compositions were analysed following 5 or 11 days of irradiation and a recovery period of 0, 5, 29 or 40 h. Concentrations of the major fatty acids, palmitic, linoleic (LA) and α‐linolenic (ALA) acids were similar in the summer and fall duckweed collections, but the summer samples had higher concentrations of the desaturation products of LA and ALA.4. UV‐B exposure had small, but significant, and contrasting effects on duckweed fatty acid concentrations. In the summer experiment, duckweed exposed to UV‐B had slightly lower concentrations of major fatty acids than control duckweed, while the reverse was true in the fall experiments.5. These minor effects of UV‐B on concentrations of LA and ALA would be unlikely to have a major impact on the supply of these essential fatty acids from duckweed to freshwater food webs.

Polyunsaturated fatty acid concentrations in human hindmilk are stable throughout 12-months of lactation and provide a sustained intake to the infant during exclusive breastfeeding: an Italian study

While a wealth of data on the fatty acid composition of mature human milk has been published, limited information is available on the quantities of individual fatty acids supplied to the suckling infant with maternal milk, through the whole first year of life. Our aim was to qualitatively and quantitatively evaluate the fatty acid composition of human milk from Italian mothers, throughout extended lactation with particular emphasis on the long-chain polyunsaturated fatty acids. We have thus measured the total fat content and the concentrations of major fatty acids by quantitative GLC in pooled breast hindmilk collected from all feedings over 24 h at colostrum, 1, 3, 6, 9 and 12 months in ten mothers recruited after delivery of full-term infants. Total saturated fatty acids progressively increase and total monounsaturated progressively decrease as percentage levels, while among long-chain polyunsaturated fatty acids, percentages of arachidonic acid and docosahexaenoic acid decrease from colostrum up to the third month. Hindmilk total lipids (mg/dl) rise more than twofold up to 3 months, and then remain stable. The amounts (mg/dl) of linoleic acid and alpha-linolenic acid progressively increase, following the trend of total fat, while arachidonic and docosahexaenoic concentrations (mg/dl) remain stable throughout the whole nursing period. Assessment of the intakes per kg body weight shows different trends for the individual major long-chain polyunsaturated fatty acids supplied to the infant from hindmilk during exclusive breast-feeding (3 months). This information may be useful for the evaluation of infant intakes during extended lactation.

Study of Lipid in the Ear Canal in Canine Otitis Externa with Malassezia pachydermatis.

An epidemiological investigation of 120 canine otitis externa cases in 1,370 dogs was done on the incidence rate, ear pinna shapes, breeds and their relationships. Eighty-five cases (12.6%) in 672 dogs with pendulous ears and 35 cases (5.0%) in 698 dogs with erect ears had otitis externa, and the difference between them was significant (P<0.05). Ninety-five auditory cerumen specimens were cultured for Malassezia pachydermatis (M. pachydermatis) and analyzed for concentrations of major fatty acids. Although rates of cases positive for M. pachydermatis in both ear pinna shapes were almost the same, i.e. 55.2% in the pendulous group and 53.6% in the erect group, the average total fatty acid level of the pendulous ear group was significantly (P<0.05) higher than that in the erect ear group after dismissing extraordinary levels in the Siberian husky. Isolated M. pachydermatis strains were examined for the effects of fatty acid supplementation on their growth. The majority of the strains utilized fatty acids and grew faster in fatty acid supplemented broth. These results suggest that M. pachydermatis, the predominant causative agent of canine otitis externa, prefers the auditory canal of dogs with lipid-rich earwax and grows fast, but growth strongly depends upon the canine breed.

Interrelation of Fatty Acid Composition in Adipose Tissue, Serum, and Liver of Dairy Cows During the Development of Fatty Liver Postpartum

We investigated the composition of fatty acids in adipose tissue, serum, and liver of cows that were fed at restricted energy intake or were overfed during the dry period. Overfed cows had higher concentrations of serum nonesterified fatty acids and consequently accumulated greater amounts of triacylglycerols in the liver than did cows that were fed at restricted energy intake. The percentages of the different fatty acids present in adipose tissue were similar for both groups and did not change during sampling intervals. Before parturition, concentrations of the individual fatty acids present in serum were similar between groups. After parturition, concentrations of major fatty acids in serum, including palmitic, stearic, oleic, and linoleic acids significantly increased in both groups and were higher in overfed cows than in cows that were fed at restricted energy intake. The shift of concentrations of the different fatty acids present in the liver—as a result of increased lipolysis—was observed in palmitic, oleic, and linoleic acids but not stearic acid, suggesting that stearic acid is used by the liver (i.e., oxidation) or is considerably secreted through the milk, thereby not increasing in accumulation in the liver. In conclusion, different feeding regimens during the dry period do not influence the composition of fatty acids in adipose tissue. More intensive lipolysis results in increased concentrations of palmitic, stearic, oleic, and linoleic acids in the blood; subsequently, these fatty acids, excluding stearic acid, greatly accumulated in the liver.

Development of calibration equations to predict oil content and fatty acid composition in brassicaceae germplasm by near‐infrared reflectance spectroscopy

AbstractThe use of nondestructive analytical methods is critical for the evaluation of very small seed samples such as those from germplasm collections. The objective of this study was to evaluate the potential of near‐infrared reflectance spectroscopy (NIRS) for the simultaneous analysis of seed oil content and concentration of major fatty acids in intact‐seed samples of the family Brassicaceae. A total of 495 samples from 56 genera and 128 species were analyzed by NIRS. The fatty acid composition of the seed oil was determined in all the samples by gas‐liquid chromatography (GLC). The total seed oil content was determined by solvent extraction in 129 samples from 22 genera. Calibration equations for oil content (n=97) and individual fatty acids (n=410) were developed and tested through external validation with the samples not included in the calibration sets. The calibration equations for oil content (r2=0.97 in validation) and concentrations of C18:1 (r2=0.93), C18:3 (r2=0.95), and C22:1 (r2=0.94) showed very good performance and provided reliable estimations of these traits in the samples of the validation set. The calibration equations for C16:0, C18:0, and C18:2 content were less reliable, with r2 from 0.67 to 0.73. There was practically no response of NIRS to differences in C20:1 (r2=0.31). These results demonstrated that the oil content and concentrations of C18:1, C18:3, and C22:1 can be estimated reliably within the family Brassicaceae by using NIRS calibration equations integrating broad taxonomic variability.

Vitamin E, Ascorbate, Glutathione, Glutathicne Disulfide, and Enzymes of Glutathione Metabolism in Cultures of Chick Astrocytes and Neurons: Evidence that Astrocytes Play an Important Role in Antioxidative Processes in the Brain

GSH, GSSG, vitamin E, and ascorbate were measured in 14-day cultures of chick astrocytes and neurons and compared with levels in the forebrains of chick embryos of comparable age. Activities of enzymes involved in GSH metabolism were also measured. These included gamma-glutamylcysteine synthetase, GSH synthetase, gamma-glutamyl cyclotransferase, gamma-glutamyltranspeptidase, glutathione transferase (GST), GSH peroxidase, and GSSG reductase. The concentration of lipid-soluble vitamin E in the cultured neurons was found to be comparable with that in the forebrain. On the other hand, the concentration of vitamin E in the astrocytes was significantly greater in the cultured astrocytes than in the neurons, suggesting that the astrocytes are able to accumulate exogenous vitamin E more extensively than neurons. The concentrations of major fatty acids were higher in the cell membranes of cultured neurons than those in the astrocytes. Ascorbate was not detected in cultured cells although the chick forebrains contained appreciable levels of this antioxidant. GSH, total glutathione (i.e., GSH and GSSG), and GST activity were much higher in cultured astrocytes than in neurons. gamma-Glutamylcysteine synthetase activity was higher in the cultured astrocytes than in the cultured neurons. GSH reductase and GSH peroxidase activities were roughly comparable in cultured astrocytes and neurons. The high levels of GSH and GST in cultured astrocytes appears to reflect the situation in vivo. The data suggest that astrocytes are resistant to reactive oxygen species (and potentially toxic xenobiotics) and may play a protective role in the brain.(ABSTRACT TRUNCATED AT 250 WORDS)

Fatty acids composition and distribution in the free lipid fraction of major types of wheat flour and bread consumed in Kuwait

Fatty acids (FA) distribution in the free lipid (FL) fraction, the concentrations of major FA in FL and the total FL contents of the major types of wheat flour ( Triticum aestivum) and bread consumed in the State of Kuwait were determined. The distribution of FA and FL (as % of total FA) showed that polyunsaturated FA (PUFA) were predominant to saturated FA (SFA) and monounsaturated FA (MUSFA) in all types of flour and bread. The concentrations of major FA in FL of flour were (mg/g); palmitic acid, 1·7–2·1; oleic acid, 1·6–2·1; linoleic, 5·5–6·7 and in FL of bread were (mg/g); palmitic, 0·7–1·1, oleic, 0·7–1·1; linoleic, 1·8–3·2. The percent content per total FA of linoleic acid was significantly lower in bread relative to flour ( P = 0·002).