Content and Fatty Acid Composition of Steryl and Wax Esters in Germinating Spores of Polytrichum commune

Polytrichum commune spores contained 5.61 ± 0.52 mg steryl and wax esters, including volatile compounds, per 100 mg dry weight of spores. Volatile compounds were not found in 3-h-old sporelings. The content of the steryl and wax ester fraction, excluding the volatile compounds, is slightly increased during the first 6 h of germination. Thereafter, the content is decreased throughout the germination. Thus, 3-day-old sporelings contained 0.52 ± 0.05 mg steryl and wax esters per 100 mg dry weight of spores. In connection with protonema growth, steryl and wax esters were produced, and the 7-day-old cultures contained 5.09 ± 0.37 mg steryl and wax esters per 100 mg dry weight of spores. The main fatty acids of the steryl and wax ester fraction of dry spores and germinating spores as well as of protonemata were palmitic, oleic, linoleic and linolenic acids. Polyunsaturated C 20 acids were present only in trace or small amounts. Phytanic and phytenic acids were found in small amounts in dry spores, in 3- to 72-h-old sporelings, and in protonemata.     

Light Dependence of Chloroplast Replication and Starch Metabolism in the Moss Polytrichum commune

Spores of Polytrichum conwtuine were grown on a mineral salt solution with or without sucrose and exposed to continuous white light, continuous darkness, red light and/or far-red light. With sucrose, germination and filament growth occurred in all conditions, Without sucrose, germination and filament growth occurred only in light. Two phytochrome mediated responses of the chloroplasts were demonstrated. Chloroplast replication occurred in continuous white light and red light of 15 min/6 hours. In continuous darkness and in far red light of 15 min/6 hours, the size of the chloroplasts increased; but no replication occurred. Both the chloroplast replication and chloroplast size were red, far-red light reversible. When changed from one continuous light environment to another, a lag period occurred before the chloroplasts responded to the new environment. Electron micrographs of sections and in vivo staining of the chloroplasts with iodine solution demonstrated that the change in size of the chloroplasts was at least partially due to the synthesis and degradation of starch.     

Determination of Fatty Acid Composition of Spore Lipids of the Moss Polytrichum commune by Glass Capillary Column Gas Chromatography

Fatty acid methyl esters of Polytrichum commune spore triglyceride and mono- and diglycosyl diglyceride fractions were analysed by glass capillary column gas chromatography provided with a precolumn system. The composition of the fatty acids in the lipid fractions differed only quantitatively: the diglycosyl diglyceride fraction was characterized by a high content of C 18: 3ω3 (67.7%), and the triglyceride and monoglycosyl diglyceride fractions by about 35%. The monoglycosyl diglyceride fraction contained a high proportion of C 14: 0 (18.4%). In all fractions the content of polyunsaturated C 20 acids was low, ranging from trace amounts to 4.9%.     

Changes in the Content of Phytyl and Geranylgeranyl Esters of Germinating Polytrichum commune Spores

Polytrichum commune spores contained esterified phytol and geranylgeraniol, 706 and 114 μg, respectively, per 100 mg dry weight of freshly collected spores. After storage for 9 months the level of esterified phytol of the spores was decreased by c. 600 μg, whereas the level of esterified geranylgeraniol was more or less unchanged. The changes in the level of esterified prenols during germination follow the same pattern in freshly collected and in 9 month-old spore material. An immediate steep decrease between 0 and 3 h was followed by an increase in the level of esterified phytol between 3 and 12 h and by a constant value for esterified geranylgeraniol during the same period. Between 12 and 48 h the level of both types of esterified prenols decreased. In the freshly collected spores the amount of esterified prenols increased after 48 h of germination, in the older spores after 72 h. Free phytol was found in trace amounts in dry and germinating spores and in the protonema.     

植物合成长链多不饱和脂肪酸研究进展

长链不饱和脂肪酸（LC-PUFAs）对人类健康具有重要作用,通过转基因植物生产LC-PUFAs具有低成本、可持续、污染少等诸多优势。本文简要介绍了LC-PUFAs的作用、来源及其植物生物合成途径,综述了转基因植物合成LC-PUFAs的研究进展,并对如何进一步提高LC-PUFAs产量进行了探讨。     

The Relationship Between Cell Size and Chloroplast Number in the Spores of a Moss, Polytrichum

The number of plastids per cell is positively correlated withcell size in immature, mature, and germinating spores, and injacket cells of antheridia. Cell enlargement occurs ahead ofplastid replication, and under normal circumstances cell sizedoes not limit plastid number. Plastid number increases in dimensionallystable cells (1) during early spore development, (2) when maturespores are incubated in chloramphenicol (CAP), and (3) after8 h incubation in the dark without inhibitors present. Cycloheximide(CHI) prevents replication but not swelling during early germination.Thus, an increase in plastid number does not always requirea change in cell size, and an increase in cell size is not alwaysaccompanied by an increase in plastid number. The findings arediscussed in relation to other results implicating phytochrome-mediatedcytoplasmic protein synthesis in plastid replication and nuclearcontrol of plastid replication.     

Effect of Long Chain Fatty Acids on Bacterial Respiration and Amino Acid Uptake

S ummary . Long chain fatty acids stimulated oxygen uptake by Gram positive bacteria at bactericidal and protoplast lytic concentrations and produced inhibition at higher levels. The order of activity between individual acids and effects of reversal agents on respiratory activity corresponded to those which produced bactericidal activity. Protoplasts were more susceptible to inhibition than whole cells. Gram negative bacteria were inhibited to a limited extent at high fatty acid concentrations, but spheroplasts were highly sensitive. Fatty acids inhibited amino acid uptake both aerobically and anaerobically at sub-bactericidal levels. The effects were reversed by metal cations, and reflected the activity of dinitrophenol and sodium azide. The susceptibility of organisms to inhibition was of the same order as the sensitivity to other antibacterial effects. The probable mode of action of the fatty acids is discussed in terms of the interference with energy metabolism within the bacterial cell.     

Physicochemical Effects of Long Chain Fatty Acids on Bacterial Cells and their Protoplasts

S ummary . Fatty acids of chain length > C₁₀ induced lysis of protoplasts at pH 7·4 when the concentration was nearly bactericidal. At pH 6, lauric and linoleic acids produced lysis above bactericidal concentrations but, at pH 8, lysis was produced by the same acids below bactericidal concentrations. The lysis was immediate at pH 8, but at pH 6 the effect was preceded by contraction of protoplasts. At pH 7·4 the order of lytic activity between individual fatty acids was similar to that of bactericidal activity and the response of protoplasts of Bacillus megaterium relative to those of Micrococcus lysodeikticus reflected differences in bactericidal sensitivity though whole cells were much less sensitive to fatty acid-induced leakage effects than protoplasts. Reversal agents antagonized the lysis of protoplasts by fatty acids. A physicochemical basis for the action of fatty acids and reversal agents on protoplasts and whole cells is discussed.     

Physical Properties of Structured Fats and Fat Blends Based on the Long Chain Fatty Acids

Food Biophysics - Enzymatic and chemical interesterification was used in preparation of structured fats without trans fatty acids. Structured fats were based on fatty acids which are not...     

Molecular Regulation of Biosynthesis of Long Chain Polyunsaturated Fatty Acids in Atlantic Salmon

Marine Biotechnology - Salmon is a rich source of health-promoting omega-3 long chain polyunsaturated fatty acids (n-3 LC-PUFA), such as eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic...     

Identification of Heptadecanoic and C19 Cyclopropane Fatty Acids in the Lipid Fraction of Zymomonas mobilis

In the present paper the presence of heptadecanoic acid and C19 cyclopropane fatty acid in Zymomonas mobilis is reported. The former has not been mentioned as a component of the lipid fraction of this microorganism, and the presence of the latter is not well documented. Received: 7 February 2000 / Accepted: 8 May 2000     

Effect of Metal Cations and pH on the Antibacterial Activity and Uptake of Long Chain Fatty Acids

S ummary . The bactericidal activity of long chain saturated fatty acids was antagonized by alkaline earth metals. The activity of linoleic acid was less effectively antagonized but was more sensitive to reversal by ferric and stannous ions. With increasing pH value the bactericidal activity of lauric acid decreased but that of the longer chain saturated acids increased. Both Gram positive and Gram negative bacteria reversibly adsorbed fatty acids. Uptake increased with decreasing pH value and increasing chain length. Although adsorbed to a lesser extent, the intrinsic activity of linoleic acid was greater than lauric acid. The uptake appeared to be non-specific and governed by the physicochemical properties of both the acids and the bacterial cell surfaces. Sensitivity to the fatty acids increased with decreasing pH value. Protoplasts of Bacillus megaterium adsorbed fatty acids to a greater extent than whole cells. Resistance of the Gram negative Pseudomonas phaseolicola was not due to non-adsorption of the fatty acids.     

Fast Diffusion of Very Long Chain Saturated Fatty Acids across a Bilayer Membrane and Their Rapid Extraction by Cyclodextrins: IMPLICATIONS FOR ADRENOLEUKODYSTROPHY*

Abnormalities in the transport of saturated very long chain fatty acids (VLCFA; >C18:0) contribute to their toxic levels in peroxisomal disorders of fatty acid metabolism, such as adrenoleukodystrophy and adrenomyeloneuropathy. We previously showed that VLCFA desorb much slower than normal dietary fatty acids from both albumin and protein-free lipid bilayers. The important step of transbilayer movement (flip-flop) was not measured directly as a consequence of this very slow desorption from donors, and the extremely low aqueous solubility of VLCFA precludes addition of unbound VLCFA to lipid membranes. We have overcome these limitations using methyl-β-cyclodextrin to solubilize VLCFA for rapid delivery to “acceptor” phosphatidylcholine vesicles (small and large unilamellar) and to cells. VLCFA binding was monitored in real time with the fluorescent probe fluorescein-labeled phosphatidylethanolamine in the outer membrane leaflet, and entrapped pyranine was used to detect flip-flop across the membrane. The upper limit of the rate of flip-flop across the membrane was independent of temperature and media viscosity and was similar for model raft and non-raft membranes as well as living cells. We further showed that cyclodextrins can extract VLCFA rapidly (within seconds) from vesicles and cells, which have implications for the mechanism and potential alternative approaches to treat adrenoleukodystrophy. Because VLCFA diffuse through the lipid bilayer, proteins may not be required for their transport across the peroxisomal membrane.     

Phs1 and the Synthesis of Very Long Chain Fatty Acids Are Required for Ballistospore Formation

The production and dissemination of spores by members of the fungal kingdom is a major reason for the success of this eukaryotic lineage in colonizing most terrestrial ecosystems. Ballistospores are a type of spore produced by basidiomycete fungi, such as the mushrooms and plant pathogenic rusts. These spores are forcefully discharged through a unique liquid-drop fusion mechanism, enabling the aerosolization of these particles that can contribute to plant disease and human allergies. The genes responsible for this process are unknown due to technical challenges in studying many of the fungi that produce ballistospores. Here, we applied newly-developed techniques in a forward genetic screen to identify genes required for ballistospore formation or function in a tractable red yeast, a species of Sporobolomyces. One strain bearing a mutation in the PHS1 gene was identified as a mirror mutant. PHS1 encodes 3-hydroxyacyl-CoA dehydratase required for the third step in very long chain fatty acid biosynthesis. The Sporobolomyces PHS1 gene complements the essential functions of a S. cerevisiae phs1 mutant. The Sporobolomyces phs1 mutant strain has less dehydratase activity and a reduction in very long chain fatty acids compared to wild type. The mutant strain also exhibits sensitivity to cell wall stress agents and loss of shooting due to a delay in ballistospore formation, indicating that the role of Phs1 in spore dissemination may be primarily in cellular integrity.     

Antibacterial Activity of Long Chain Fatty Acids and the Reversal with Calcium, Magnesium, Ergocalciferol and Cholesterol

SUMMARY: Screening tests indicated that Gram positive bacteria are inhibited by long chain fatty acids. No inhibition was demonstrated with Gram negative bacteria. The minimum inhibitory concentrations (MIC) for a series of the fatty acids are presented. Growth curves in the presence of linolenic acid showed increases in lag phase duration and calcium addition reversed this effect, thus indicating the arbitrary nature of the MIC values. Bactericidal studies showed lauric acid to be the most active saturated fatty acid but the activity was less than that of the C₁₈ unsaturated fatty acids. Oleic acid was more effective than elaidic acid. Calcium ions, cholesterol and ergocalciferol reversed the activities of lauric and linoleic acids but magnesium ions effectively counteracted lauric acid only. A physicochemical explanation for the relative activities has been attempted.     

A Study on the Main Fatty Acids and Triglyceride Composition of Kernel Oil of Iodes vitiginea

The kernel of lodes vitiginea (Hance) Hemsl. (Icacinaceae) contains 39---50% of oil. Analysing with GC, the main fatty acids are hexadecenoic and palmitic acid. By means of ozonization, GC/MS, IR, etc., the hexadecenoic acid was identified as cis- 7-hexadecenoic acid. Thirteen triglycerides (peak) have been separated by HPLC from oil, among them, eight triglycerides were identified by C,C with HHH, 18.4; HHP, 32.3%; PHP, 16.8% as the main composition.     

樱桃李核仁油脂肪酸组成分析

采用气相色谱法及气相色谱-质谱联机技术,对樱桃李Prunus divaricata Ldb.核仁油中的脂肪酸进行了定量、定性分析.其脂肪酸组成为油酸66.3%、亚油酸25.6%、棕榈酸5.6%、硬脂酸1.4%,不饱和脂肪酸油酸和亚油酸的总量占91.9%,该油有较高的营养价值.     

Saturated,Monounsaturated and Polyunsaturated Fatty Acids Intake and Risk of Pancreatic Cancer: Evidence from Observational Studies

Background

Although the relationship between dietary monounsaturated fatty acids (MUFAs), polyunsaturated fatty acids (PUFAs), and saturated fatty acids (SFAs) intake and pancreatic cancer risk has been reported by several studies, the evidence is controversial. We firstly conducted this comprehensive meta-analysis to summarize the aforementioned evidence from observational studies.

Methods

The MEDLINE (PubMed), Embase, and ISI Web of Science databases were used to search for epidemiological studies of dietary SFA, MUFA, and PUFA and pancreatic cancer risk that were published until the end of June 2014. Random- or fixed-effects models were used to estimate the relative risks (RRs) and 95% confidence intervals (CIs). We also carried out subgroup, sensitivity, and publication bias analyses.

Results

We identified 13 case-control studies and 7 prospective studies which including 6270 pancreatic cancer cases in the meta-analysis of SFA, MUFA, and PUFA and risk of pancreatic cancer. The summary RR was 1.13 (95%CI = 0.94-1.35, I ² = 70.7%) for SFA, 1.00 (95%CI = 0.87-1.14, I ² = 43.4%) for MUFA, and 0.87 (95%CI = 0.75-1.00, I ² = 55.3%) for PUFA for high versus low intake categories. We found no evidence of publication bias.

Conclusion

In summary, findings of this study supports an inverse association between diets high in PUFA and pancreatic cancer risk. Further large prospective studies are warranted to report the results stratified by the subtypes of MUFA and PUFA and adjust for other potential risk factors to eliminate residual confounding.