No description available.

Proteins and fatty acids often exist in solutions containing biological matter that are treated with membranes. These proteins and fatty acids interact with each other as well as with the membranes thereby affecting the flux. Binding of fatty acids to proteins results in complexes that are much larger than fatty acid molecules. Exploitation of this size difference to remove difficult to separate fatty acids from aqueous solutions by ultrafiltration was investigated in this study. In addition, the fouling of membrane by the protein-fatty acid mixtures containing free dissolved fatty acids was studied using bovine albumin (BSA)-caprylic system. Binding of caprylic acid to native and pasteurized BSA was examined by diafiltering pre equilibrated fatty acid-BSA mixtures. The rate of mass transfer of fatty acid molecules through boundary film surrounding the protein molecules was estimated using a BSA solution as the adsorbent phase in an agitated column. A stirred cell fitted with a polyethersulfone membrane (30 kDa) was used for the diafiltrations. Accumulation of fatty acid in the BSA layers fouled on the membrane was also estimated. Binding studies indicate that a native BSA molecule (at pH 6.8) could bind 7 fatty acid molecules in specific binding cavities while approximately 44 molecules are bound onto the surface. When BSA was pasteurized the specific binding decreased from 7 to 2 indicating unfolding of the molecule. In addition, the total binding capacity decreased from 44 to 24 moles/BSA mole and the rate of mass transfer decreased from 4.5/min to 3.6/min, indicating heat induced aggregation of BSA. At alkaline pH levels fatty acid anion acts as an anionic surfactant stabilizing the molecular conformation of the protein and reducing fouling. When pH was lowered to 3, flux severely declined. Unusually large accumulation of fatty acid in the deposited protein layers (caprylic/BSA ~ 10,000 moles) occurred indicating capillary condensation of undissociated fatty acids in the protein layer. Agitated column studies showed that proteins could be used as an adsorbent to remove hard to separate dissolved fatty acids from aqueous solutions. The separated protein-fatty acid complex may be further processed to manufacture animal feed.

"October 2003" Bibliography: leaves 190-210. Ch. 1. Literature review -- Ch. 2. A practical approach to increasing intakes of n-3 polyunsaturated fatty acids: use of novel foods enriched with n-3 fats -- Ch. 3. Effects of fatty acids on the incidence of arrhythmias in patients with implanted cardioverter-defibrillators (ICDs) -- Ch. 4. A pilot study to investigate the effects of n-3 fatty acids on inducible, sustained ventricular tachycardia in patients undergoing electrophysiology testing -- Ch. 5. Conclusions and future directions.

"October 2003" / Bibliography: leaves 190-210. / xxi, 210 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Medicine, 2003

Thesis (Ph.D.)--McMaster University, 2005. / Supervisor: Paul Harrison. Includes bibliographical references (leaves 192-207).

Age-related changes in the pH of the medium, fatty acid composition and biosynthesis of fatty acids in various subcellular fractions have been studied in submerged cultures of P. chrysogenum harvested at pH's 7.2, 4.8, 4.4 and 3.8. 14C - labeled lauric and myristic acids were each incubated with cell fractions prepared by sonification and fractional centrifugation. Products were analyzed by thin layer chromatography, gas liquid scintillation spectrometry. Conversion of labeled precursors into longer chain saturated and unsaturated fatty acids was employed as a measure of the activity of the various cell fractions.It was found that between pH 4.8 and 4.4 of the age of the culture a period of maximum fatty acid synthesis occured at the time when glucose was being taken up to a greatest extent from the medium and when cells start rapidly increasing in growth. This correlated to the increased rate of de novo synthesis in the soluble cytoplasmic fraction.The fermentation products, formic, acetic, proprionic, butyric and gluconic acid, produced at different time points of the age of the culture, accounted for the drop in the pH of the medium.

No description available.

The use of cooled and frozen/thawed semen offers many advantages to breeders. However, many stallions produce spermatozoa that are unable to endure the stresses of cooling/storage and freezing/thawing. Improving the quality and viability of equine spermatozoa via appropriate dietary manipulation could make these stallions commercially viable for cooling or cryopreservation. To evaluate whether spermatozoa quality and viability can be improved by supplementation of omega-3 fatty acids, and if improvements can be made by altering the sources of these fats, nine miniature stallions were placed into 1 of 2 treatment groups and fed either a fish- or algae/flaxseed-based supplement which was added to the basal concentrate. Motion characteristics, membrane integrity and morphology of spermatozoa in fresh, cooled/stored (24 and 48 h), and frozen/thawed semen samples were analyzed. When comparing spermatozoa obtained from stallions in each treatment, no differences were found (P > 0.05) in motility, percentage of membrane intact spermatozoa, and percentage of morphologically normal spermatozoa of stallions. Overall, omega-3 supplementation did not appear to have a beneficial effect on offsetting the harmful effects of the cooling and freezing processes. However, when analyzing the data of one stallion that had < 40% progressive motility (PMOT) after 24 h of cooling and storage, a significant increase was observed in total motility, and progressive motility of fresh and 24 h cooled/stored spermatozoa was observed when supplemented with the fish-based supplement. Thus, omega-3 fatty acid supplementation may be most beneficial for stallions that produce lower quality ejaculates. However, further studies should be conducted, with a larger sample size, in order to substantiate these findings.

Thesis (Ph. D.)--Faculty of Agriculture, University of Sydney, 1998. / Bibliography: leaves 184-218. Also available in print form.

Thesis (Ph.D.)--University of Nebraska-Lincoln, 2009. / Title from title screen (site viewed October 15, 2009). PDF text: vii, 163 p. : ill. (some col.) ; 7 Mb. UMI publication number: AAT 3369413. Includes bibliographical references. Also available in microfilm and microfiche formats.