Fatty acids

Fatty acid composition of human milk (HM) is known to change considerably during lactation. However, we were unable to find data on changes of fatty acid composition of HM during the very early phase of lactation, i.e. in the first week of life. HM samples were obtained from 18 healthy lactating women every day during the first week and thereafter on the 14th and 28th days of lactation. Fatty acid composition of colostrum and mature HM samples was determined by high-resolution capillary gas-liquid chromatography. Values of the n-6 essential fatty acid, linoleic acid, in HM did not change significantly during the first month of lactation, whereas values of the n-3 essential fatty acid, alpha-linolenic acid, showed significant increases during the first 2 weeks of lactation (1st day: 0.49 [0.12], % weight/weight, median [ranges from the 1st to the 3rd quartile], 14th day: 0.69 [0.31], p < 0.05). In contrast, values of the n-6 long-chain metabolites, eicosadienoic-, dihomo-gamma-linolenic- and arachidonic acid, as well as the values of the n-3 long-chain metabolites, eicosatrienoic-, and eicosapentaenoic acid exhibited significant decreases during the entire period investigated. The principal n-3 long-chain metabolite, docosahexaenoic acid, showed a significant increase between the 3rd and 14th days, but a significant decrease between the 14th and 28th days (3rd day: 0.15 [0.13], 14th day: 0.28 [0.11], p < 0.05, 28th day: 0.19 [0.12], p < 0.01). There were statistically significant positive correlations between arachidonic and docosahexaenoic acid values on the 1st (r = 0.67, p < 0.01), 5th (r = 0.56, p < 0.05) and the 6th (r = 0.53, p < 0.05) days of lactation. Fatty acid composition of HM changes significantly even during the first week of lactation. The lack of positive correlation between essential fatty acids and their long-chain metabolites suggests that it is not only the availability of essential fatty acids that influences the fatty acid composition of human colostrum.

High pressure homogenization (HPH) was tested for inducing autolysis in a commercial strain of Saccharomyces bayanus for winemaking. The effects on cell viability, the release of soluble proteins, glucidic colloids and amino acids in wine-like medium and the volatile composition of the autolysates were investigated after processing, in comparison with thermolysis. HPH seemed a promising technique for inducing autolysis of wine yeasts. One pass at 150MPa was the best operating conditions. Soluble colloids, proteins and free amino acids were similar after HPH and thermolysis, but the former gave a more interesting volatile composition after processing, with higher concentrations of ethyl esters (fruity odors) and lower fatty acids (potential off-flavors). This might allow different winemaking applications for HPH, such as the production of yeast derivatives for wine ageing. In the conditions tested, HPH did not allow the complete inactivation of yeast cells; the treatment shall be optimized before winemaking use.

The pulp and paper industry generates significant amounts of waste from various processes consisting of organic and inorganic matter. Due to its composition, the management of pulp and paper mill sludge presents an economic burden for wastewater treatment plants. In South Africa, paper mill sludge is mainly incinerated, landfilled or used for land application. These practices cause environmental and health hazards. In this study, a process of stabilization of paper mill sludge through hydrothermal carbonization is proposed. The quality of biochar produced and energy yield will depend on the elemental composition, calorific value and ash content of the sludge. Results revealed samples are composed of flat fibrous cellulosic morphology, with high volatile matter and little fixed carbon percentage. The main decomposition occurred between 220-400 °C. Sludge from primary clarifier contains the highest ash percentage, hence it was found to be unsuitable for energy recovery through hydroth...

Many healthy subjects and patients are taking natural bioactive products for the prevention and treatment of multiple conditions, including gastrointestinal disorders. Based on current evidence, the scientific validity of the use of many of these commercial compounds by the ...

Phospholipid fatty acid (PLFA) analysis of a soil microbial community was coupled with 13C isotope tracer analysis to measure the community’s response to addition of 35 μg of [13C]toluene ml of soil solution−1. After 119 h of incubation with toluene, 96% of the incorporated 13C was detected in only 16 of the total 59 PLFAs (27%) extracted from the soil. Of the total 13C-enriched PLFAs, 85% were identical to the PLFAs contained in a toluene-metabolizing bacterium isolated from the same soil. In contrast, the majority of the soil PLFAs (91%) became labeled when the same soil was incubated with [13C]glucose. Our study showed that coupling 13C tracer analysis with PLFA analysis is an effective technique for distinguishing a specific microbial population involved in metabolism of a labeled substrate in complex environments such as soil.

SYNOPSIS. An age-autolyzed culture of Chroomonas salina, grown under cool-white light with glycerol, produced waxy lipid constituting about 44% of total matter harvested. This lipid was composed of 87% wax ester, 9% triglyceride, 3% polar lipid and 1% hydrocarbon. The major wax ester species were identified by total carbon number as C26(28%), C28(35%), C30(15%). The main fatty acid components of the wax esters were 12:0 (39%), 14:0 (30%), 16:0 (14%), while the main alcohols were 14:0 (53%) and 16:0 (40%). The hydrocarbon fraction showed saturated paraffins ranging from C17 to C33, with odd-numbered chain components predominating. No polyunsaturated components were detected in the wax ester or hydrocarbon fractions. This is the first record of wax ester production by a cryptomonad or a marine phytoplankter.

The entire pathway of palmitate synthesis from malonyl-CoA in mammals is catalyzed by a single, homodimeric, multifunctional protein, the fatty acid synthase. Each subunit contains three N-terminal domains, the β-ketoacyl synthase, malonyl/acetyl transferase and dehydrase separated by a structural core from four C-terminal domains, the enoyl reductase, β-ketoacyl reductase, acyl carrier protein and thiosterase. The kinetics and specificities of the substrate loading reaction catalyzed by the malonyl/acetyl transferase, the condensation reaction catalyzed by β-ketoacyl synthase and chain-terminating reaction catalyzed by the thioesterase ensure that intermediates do not leak off the enzyme, saturated chains exclusively are elongated and palmitate is released as the major product. Only in the fatty acid synthase dimer do the subunits adopt conformations that facilitate productive coupling of the individual reactions for fatty acid synthesis at the two acyl carrier protein centers. Introduction of a double tagging and dual affinity chromatographic procedure has permitted the engineering and isolation of heterodimeric fatty acid synthases carrying different mutations on each subunit. Characterization of these heterodimers, by activity assays and chemical cross-linking, has been exploited to map the functional topology of the protein. The results reveal that the two acyl carrier protein domains engage in substrate loading and condensation reactions catalyzed by the malonyl/acetyl transferase and β-ketoacyl synthase domains of either subunit. In contrast, the reactions involved in processing of the β-carbon atom, following each chain elongation step, together with the release of palmitate, are catalyzed by the cooperation of the acyl carrier protein with catalytic domains of the same subunit. These findings suggest a revised model for the fatty acid synthase in which the two polypeptides are oriented such that head-to-tail contacts are formed both between and within subunits.

Four orange-pigmented isolates, L7-456, L7-484T, L9-479 and L9-753T, originating from surface-sterilized leaf tissues of Jatropha curcas L. cultivars were characterized using a polyphasic taxonomic approach. Phylogenetic analyses based on 16S rRNA gene sequences indicated that all four isolates belong to the genus Aureimonas . In these analyses, strain L7-484T appeared to be most closely related to Aureimonas ureilytica 5715S-12T (95.7 % sequence identity). The 16S rRNA gene sequences of strains L7-456, L9-479 and L9-753T were found to be identical and also shared the highest similarity with A. ureilytica 5715S-12T (97.5 %). Both L7-484T and L9-753T contained Q-10 and Q-9 as predominant ubiquinones and diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, phosphatidylmonomethylethanolamine, phosphatidylethanolamine, phosphatidyldimethylethanolamine, sulfoquinovosyldiacylglycerol and an aminophospholipid as the major polar lipids. C18 : 1ω7c and C16 : 0 were the major fa...

The objective of this study was to assess how probiotic bacteria added to diets of 60 hybrid barrows (Landrace-Yorkshire x Duroc) affected the basic chemical composition of meat, the fatty acid profile of intramuscular fat (IMF), m. longissimus lumborum (LL) and lipid quality indices, because IMF cannot be removed before consumption and this inevitably has an impact on human health. After 78 days, the pigs were divided into the control group (CT, n=30) and the experimental group (BP, n=30), which until 97 days of rearing were supplied with BioPlus YC probiotic (Bacillus licheniformis DSM 5749 and Bacillus subtilis DSM 5750). After slaughter, 12 carcasses of similar weight (90 ± 5 kg) from each group were selected for testing. Supplementation with probiotic Bacillus did not affect the basic chemical composition of meat. It was established that BioPlus YC had a significant impact on capric-C10:0 (0.08 vs. 0.13), eicosatrienoic-C20:3 n-3 (1.76 vs. 2.14) and ΣPUFA n-3 acids (1.88 vs. 2.41), causing a reduction in their percentage, which was thereby different than in the CT group. Among lipid quality indices, IMF LL of pigs from the BP group, the thrombogenicity index (TI) was characterized by a significantly (P≤0.01) higher value than in the CT group (1.08 vs. 0.99). These results suggest that further research is needed to study differences in compounds affecting the fatty acid profile of pork, and to confirm the association of the lipid profile with the use of BioPlus YC probiotic in pig fattening.

Assessment of free fatty acid (FFA) concentration and isotopic enrichment is useful for studies of FFA kinetics in vivo. A new procedure to recover the major FFA from plasma for concentration and isotopic enrichment measurements is described and validated. The procedure involves extraction of plasma lipids with hexane, methylation with iodomethane (CH(3)I) to form fatty acid methyl esters (FAME), and subsequent purification of FAME by solid phase extraction (SPE) chromatography. The new method was compared with a traditional method using thin-layer chromatography (TLC) to recover plasma FFA, with subsequent methylation by BF(3)/methanol. The TLC method was found to be less reliable than the new CH(3)I method because of contamination with extraneous fatty acids, chemical fractionation of FFA species, and incomplete recovery of FFA associated with TLC. In contrast, the CH(3)I/SPE method was free of contamination, did not exhibit chemical fractionation, and had higher recovery. The iod...

Derivatives of the tyrosine kinase inhibitor dasatinib were synthesized by esterification with 25 carboxylic acids, including amino acids and fatty acids, thereby extending the drug to interact with more diverse sites and to improve specificity. The dasatinib-l-arginine derivative (Das-R, 7) was found to be the most potent of the inhibitors tested, with IC50 values of 4.4, <0.25, and <0.45 nm against Csk, Src, and Abl kinases, respectively. The highest selectivity ratio obtained in our study, 91.4 Csk/Src, belonged to compound 18 (Das-C10 ) with an IC50 value of 3.2 μm for Csk compared with 35 nm for Src. Furthermore, many compounds displayed increased selectivity toward Src over Abl. Compounds 15 (Das-glutamic acid) and 13 (Das-cysteine) demonstrated the largest gains (10.2 and 10.3 Abl/Src IC50 ratios). Das-R (IC50 =2.06 μm) was significantly more potent than the parent dasatinib (IC50 =26.3 μm) against Panc-1 cells, whereas both compounds showed IC50 <51.2 pm against BV-...