Production of 3-hydroxy fatty acids by the yeast Dipodascopsis uninucleata. Biological implications.
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Fatty Acids, Unsaturated↗
Biomedical subjects
A Botha
Publications and source records attributed to A Botha.
An isolation procedure for arachidonic acid producing Mortierella species.
Malt extract agar and an incubation temperature of 5 degrees C were used to selectively isolate representatives of the genus Mortierella from soil. Fungi in a soil sample from mountain grassland able to grow under these conditions, amounted to a total of 2640 colony forming units per gram soil. Circa 94% of the total fungal isolates represented Mortierella subgenus Mortierella. The rest of the colony-forming units consisted of Mucor isolates (6.0%) and higher fungi (1.5%). All the Mortierella isolates produced arachidonic acid.
Arachidonic Acid↗
Oxylipin formation in fungi: biotransformation of arachidonic acid to 3-hydroxy-5,8-tetradecadienoic acid by Mucor genevensis.
The soil fungus Mucor genevensis was shown to convert exogenous arachidonic acid to the oxylipin 3-hydroxy-5Z,8Z-tetradecadienoic acid (3-HTDE) as determined by gas chromatography/mass spectrometry. This metabolite was only found in the aqueous supernatant together with free linoleic acid, but not in the final fungal biomass. In contrast, the corresponding primary arachidonic acid metabolite (3R)-hydroxy-(5Z,8Z,11Z,14Z)-eicosatetraenoic acid (3-HETE), which has been earlier shown to be produced by the yeast Dipodascopsis uninucleata, could not be detected. These observations may be plausibly explained by a retroconversion by M. genevensis of arachidonic acid to linoleic acid before the latter is metabolised to 3-HTDE.
Arachidonic Acid↗
Helicobacter pylori: the mouth, stomach, and gut axis.
The aim of this study was to identify the natural reservoir and route of transmission of Helicobacter pylori infection. Two hundred eight (208) dyspeptic patients (114 males, 94 females; peak age of cohort, 50-59.9) were recruited. Specimens were collected from saliva, supra- and subgingival dental plaque, tongue scrapings, and oropharyngeal swabs. At subsequent endoscopy, gastric antral biopsy was performed for the rapid urease test (RUT), microbiological culture, and, in some patients, histology. Gastric juice samples were aspirated, and in 50 patients duodenal aspirate was collected. Polymerase chain reaction (PCR) with primers targeted to the 16S rRNA sequence of H. pylori was also employed for each of the specimens. In those patients where H. pylori was detected from multiple sites (dental plaque, gastric juice, gastric biopsy, and duodenal aspirate), restriction endonuclease digestion with Hae III was performed to determine if they were epidemiologically linked. The results indicated that 15/208 patients (7%) tested positively for H. pylori by PCR in dental plaque; only 2 samples were positive by culture. In none of the other oral sites sampled was H. pylori detected by any test used in the study. Gastric juice and gastric biopsy specimens from 36/ 208 patients (17%) and 114/208 patients (55%), respectively, were positive by PCR. Duodenal aspirate from 6/50 patients (12%) also tested positively by PCR. All specimens tested by restriction endonuclease digestion with Hae III (15/15 patients) were positive in both antral biopsy and gastric juice specimens, as well as 5 specimens from the duodenal aspirate. Four of the dental plaque strains had restriction patterns similar to those of the stomach and duodenal sites, providing evidence that these sites were infected with the same strain of H. pylori. In conclusion, the results suggest that H. pylori selects the gastric mucosa as its preferred site. The detection in dental plaque could indicate that the oral cavity may act as a reservoir or sanctuary for the organism. Whether H. pylori is a resident or transient oral microorganism is still unclear, although it is more likely to be transient in nature.
Bacterial Typing Techniques↗
The production of biologically active eicosanoids by yeasts.
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Eicosanoids↗
The production of eicosanoid precursors by mucoralean fungi.
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Eicosanoids↗
Production of 3R-hydroxy-polyenoic fatty acids by the yeast Dipodascopsis uninucleata.
Various fatty acids were fed to the yeast Dipodascopsis uninucleata UOFS Y 128, and the extracted samples were analyzed for the accumulation of 3-hydroxy metabolites with the help of electron impact gas chromatography-mass spectrometry. Fatty acids containing of 5Z,8Z-diene system (5Z,8Z,11Z-eicosatrienoic, 5Z,8Z,11Z,14Z-eicosatetraenoic, and 5Z,8Z,11Z,14Z,17Z-eicosapentaenoic acids) yielded the corresponding 3-hydroxy-all-Z-eicosapolyenoic acids. Moreover, linoleic acid (9Z,12Z-octadecadienoic acid) and 11Z,14Z,17Z-eicosatrienoic acid were converted to the 3-hydorxylated metabolites of shorter chain length, e,g., 3-hydroxy-5Z,8Z-tetradecadienoic acid and 3-hydroxy-5Z,8Z,11Z-tetradecatrienoic acid, respectively. In contrast, no accumulation of a 3-hydroxy metabolite was observed with oleic acid (9Z-octadecenoic acid), linolelaidic acid (9E,12E-octadecadienoic acid), gamma-linolenic acid (6Z,9Z,12Z-octadecatrienoic acid), and eicosanoic acid as substrate. These findings pinpoint that the 3-hydroxylation of a fatty acid in Dipodascopsis uninucleata requires a 5Z,8Z-diene system either directly or following initial incomplete beta-oxidation. Following analysis of the enantiomer composition, the arachidonic acid metabolite was identified as 3R-hydroxy-5Z,8Z,11Z,14Z-eicosatetraenoic acid, which rules out a normal beta-oxidation as biosynthetic route to this new class of oxylipins.
Arachidonic Acids↗
Physiological properties and fatty acid composition in Mucor circinelloides f. circinelloides.
Sporangiospores of Mucor circinelloides f. circinelloides CBS108.16 could germinate and grow on a wide variety of carbon sources in synthetic liquid media. Growth was supported by aldoses which have the same configuration at carbon atom number two as glucose. Di- and trisaccharides consisting of D-glucopyranosyl moieties were assimilated, while polysaccharides like inuline and starch were also utilised. Various alcohols and organic acids could be assimilated, while the phenolic compounds tested could not support aerobic growth. The fungus was able to ferment carbohydrates consisting of D-glucopyranosyl moieties, grow in the absence of vitamins and in the presence of cycloheximide. It also liquefied gelatin and produced lipases and cellulolytic enzymes. It was found that the highest percentages polyunsaturated fatty acids were produced when acetic acid, glucose, mannitol, soluble starch or trehalose was used as carbon source. The absence of vitamins in the medium lowered the percentage of these fatty acids.
Acids↗
Lipomyces mesembrius sp. nov., a member of the L. starkeyi species-complex.
Lipomyces starkeyi is known to be associated with three strains-clusters showing high mutual nDNA reassociation within each cluster, but which reassociate ambiguously with the type of L. starkeyi. Representative strains of L. starkeyi and Cluster alpha were examined for possible genetic exchange by the prototrophic selection technique. Since no genetic recombination was detected, the strains are presumed to be genetically isolated. Cluster alpha is consequently assigned to the rank of species as Lipomyces mesembrius. A description of the new species is given. Lipomyces kononenkoae ssp. spencermartinsiae has been raised to the rank of species as L. spencermartinsiae.
Classification↗
The production of gamma-linolenic acid by selected members of the Dikaryomycota grown on different carbon sources.
In this study, seven fungal strains, representing different phylogenetic groups within the Dikaryomycota, were tested for the presence of gamma-linolenic acid [18:3(omega 6)], when grown in synthetic liquid media devoid of fatty acids, on a series of 40 different carbon sources. The fungal strains represented the species Dipodascopsis uninucleata, Eurotium rubrum, Galactomyces geotrichum, Neurospora crassa, Saccharomyces cerevisiae, Spongipellis unicolor and Talaromyces flavus. Cultures were periodically harvested during growth and the fatty acids in the total lipids analysed as methyl esters, using gas chromatography and mass spectrometry. It was found that 18:3(omega 6) is present in E. rubrum CBS 350.65, S. unicolor CBS 117.16 and in T. flavus CBS 310.38NT, when these strains were grown on certain carbon sources. No correlation between the growth phase of the organism and the presence of 18:3(omega 6) could be detected. In order to confirm the production of 18:3(omega 6), the lipid metabolism of two unrelated dikaryomycotan fungi (S. unicolor CBS 117.16 and E. rubrum CBS 350.65) grown on two different carbon sources each, was examined. Cultures of E. rubrum CBS 350.65 were grown on glucose and sorbose and cultures of S. unicolor CBS 117.16 on glucose and sucrose in synthetic liquid media with a C:N ratio of 50:1 (w/w). The total lipids of these cultures were fractionated and the fatty acids in the fractions analysed as methyl esters, using gas chromatography and mass spectrometry. The lipid metabolism of both E. rubrum CBS 350.65 and S. unicolor CBS 117.16 differed on the two carbon sources used. The ab initio production of 18:3(omega 6) by E. rubrum CBS 350.65 in synthetic liquid media was confirmed. In contrast, the ab initio production of 18:3(omega 6) by S. unicolor CBS 117.16 in synthetic liquid media could not be confirmed.
Acids↗
The value of lipid composition in the taxonomy of the Schizosaccharomycetales.
In this study, the lipid fractions i.e. neutral (NL), phospho-(PL) and glycolipids (GL) with associated fatty acids (FAs) of 54 strains, representing the Schizosaccharomycetales, were analyzed during stationary growth phase and compared. Trace amounts of linoleic acid (18:2) were present in most of the strains representing Schizosaccharomyces. An increased percentage 18:2 was observed in the PL fraction when compared to the NL fraction. This is possibly related to membranes requiring polyunsaturated FAs for fluidity. On the basis of the percentage oleic acid (18:1) and 18:2 FAs in the different lipid fractions, the Schizosaccharomycetales can clearly be divided into two groups i.e. Group 1 (represented by the genus Hasegawaea) comprising strains producing relatively large amounts of 18:2 and relatively low amounts of 18:1 when compared to Group 2 (represented by the genus Schizosaccharomyces comprising Schizosaccharomyces octosporus and Schizosaccharomyces pombe). These results are in accordance with 18S and 26S rRNA base sequence analyses and emphasize the difference between the genera Hasegawaea and Schizosaccharomyces. Utilizing gas chromatography-mass spectrometry analyses, it was found that these strains were all capable of producing gamma-linolenic acid. This further emphasizes the uniqueness of this order in the Dikaryomycota.
Chromatography, Thin Layer↗
Application of fatty acid profiles in the identification of yeasts.
In order to develop a rapid yeast identification technique using fatty acid profiles, an extensive survey has been conducted in our laboratory on the long-chain fatty acid composition (CLFAC) of yeasts representing the endomycetous and basidiomycetous yeast domain. It was accomplished by cultivating the yeast strains under standardized conditions in a synthetic liquid medium. When stationary phase was reached the cells of each culture were freeze-dried and the CLFAC was examined by gas chromatography. It was found that the fatty acid profile obtained for each strain was reproducible. However, as work progressed, it became clear that variation exists within species and that the relative percentages of some strains from different species may overlap. Identification of species could therefore not be achieved in all attempts, even when the resolution of the fatty acid analyses was enhanced by using capillary columns, useful for the detection of minor fatty acids. When used in isolation, CLFAC analyses is therefore not a generally applicable identification technique for yeast species. However, the technique was found to be a valuable chemotaxanomical tool to distinguish between strains of certain species, species of certain genera and species from particular environments. The technique currently finds application in the South African food and beverage industry as a quick, cheap and easy way to distinguish between strains of Saccharomyces cerevisiae. It is also used by an industry which produces bioprotein from Geotrichum candidum, to determine fungal contaminants in a quality control process.
Fatty Acids↗
The distribution and taxonomic value of fatty acids and eicosanoids in the Lipomycetaceae and Dipodascaceae.
Using radioimmunoassay, blood platelet aggregation studies and GC-MS the existence of prostaglandins in the endomycetalean yeast Dipodascopsis uninucleata was confirmed by our group. These findings triggered the search for similar eicosanoids in the rest of the Endomycetales. We commenced by scanning for the easily detectable precursors of eicosanoids, linoleic- and linolenic acid. We selected two families (i.e. Lipomycetaceae and Dipodascaceae), both producing these precursors, for further investigation. Representative strains of the two families were tested for their ability to grow in the presence of 1 mM aspirin, a specific inhibitor of prostaglandin biosynthesis. In contrast to the lipomycetaceous species the dipodascaceous species were insensitive to this drug. These results were verified when representative strains of both families were investigated for their ability to produce eicosanoids from externally fed radio-labeled arachidonic acid along an aspirin sensitive pathway. Thin layer chromatography of culture extracts, followed by autoradiography, showed that while none of the Dipodascaceae produced aspirin sensitive arachidonic acid metabolites, the members of the Lipomycetaceae tested positive for these metabolites. These findings supported the separation of the lipomycetaceous yeast Dipodascopsis from the Dipodascaceae. The findings also correlate with the delimitation of these yeasts in two families (i.e. Dipodascaceae and Lipomycetaceae). Further investigation indicated that prostaglandin production by the genus Dipodascopsis is mainly associated with ascosporogenesis. Thin layer chromatography of cell extracts from Dipodascopsis tóthii, followed by scintillation counting, indicated the presence of PGF2 alpha and PGE2 during ascosporogenesis.
Arachidonic Acid↗
[Percutaneous transluminal coronary angioplasty].
Percutaneous Transluminal Coronary Angioplasty is a cardiologic technique utilised for increasing the luminal diameter of a coronary artery with an atheroma lesion without performing major surgery. Nursing these patients requires specific nursing interventions. Patient education, both before and after the procedure, is most important. Meticulous assessment and monitoring of the patient's ECG, other vital signs and the site of the sheath must be maintained and the nurse needs to plan her nursing actions according to these requirements.
Angioplasty, Balloon, Coronary↗
Evidence for, and taxonomic value of, an arachidonic acid cascade in the Lipomycetaceae.
By using specific inhibitors of the lipoxygenase and cyclo-oxygenase pathways, arachidonic acid metabolites with similar sensitivities towards these inhibitors as in humans, were detected in Dipodascopsis uninucleata. The taxonomic value of aspirin sensitive arachidonic acid metabolites in the Lipomycetaceae was next assessed. No metabolites of which the production is inhibited by aspirin were detected in strains representing the following species: Lipomyces starkeyi, Lipomyces kononenkoae, Lipomyces tetrasporus, Myxozyma melibiosi, Myxozyma mucilagina, Myxozyma kluyveri, Waltomyces lipofer, Zygozyma oligophaga and Zygozyma arxii. The detection of such aspirin sensitive arachidonic acid metabolites in representative strains of Lipomyces anomalus and the genus Dipodascopsis, emphasises the isolated position of these taxa in the genus Lipomyces and the family Lipomycetaceae, respectively. Finally using long chain fatty acid analyses, electrophoretic karyotyping and other phenotypic characters, a phylogenetic scheme is proposed for some genera in the Lipomycetaceae.
Arachidonic Acid↗
Helicopter doctors?
All roadside procedures carried out by doctors of the Royal London Hospital Helicopter Emergency Medical Service were recorded. Of 100 injured patients treated consecutively, 68 patients required 73 treatments or procedures that were beyond the current training of the ambulance paramedic in the United Kingdom. Doctors are therefore an essential part of HEMS operations and allow earlier live-saving medical intervention in the prehospital phase of care.
Aircraft↗
An exploratory study of the ways in which mothers keep their infants occupied.
The mother child relationship can help or hinder the social, emotional and intellectual development of the infant. Research has shown that the interaction between mother and child can affect the child's cognitive development. Research has shown that mothers from the lower socio-economic groups do not stimulate their babies optimally and that this may affect the children negatively. In this study 86 underprivileged mothers from two different cultural backgrounds were asked to describe the ways in which they kept their infants occupied during the first year of their infants' lives. The differences between the two groups are discussed and recommendations are made.
Adolescent↗
[The nurse's role in cardiac rehabilitation].
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Cardiac Rehabilitation↗