In an effort to determine the relative amount of carbohydrates and free fatty acids (FFA) utilized by trained and untrained men at a submaximal workload and the relationship of selected mitochondrial and glycolytic enzyme activities, six trained and six untrained males were exercised for one hour at 50o of their maximal oxygen uptake (V02 max).Muscle samples were taken from the vastus lateralis in three cyclists and from the gastrocmemius in three runners from each group before and after exercise, and later assayed for succinic acid dehydrogenese, malic acid dehydrogenase, lactic acid dehydrogenase, phosphorylane, and carnitine paLmityltransf erase activities, and glycogen levels. Th e post exercise sample was assayed for glycogen, another was sectioned and stained for glycogen and fiber composition (PAS and-glycerolphosphate dehydrogenase) and from a third coupled mitochondria were isolated to determine 14'CO2 production from oxidation of varied levels of 14C-palmityl-CoA. Blood drawn before, immediately after, and thirty minutes after the exercise was assayed for FFA, glycerol, triglycerides, and glucose levels. Activities of oxidative enzymes (SDH, MDH, and CPT) were significantly higher (2-3 times greater) in the trained individuals than in the untrained group. Glycolytic enzyme activities were higher in the untrained group, probably due to higher fast twitch fiber populations. During exercise, FFA levels rose to the same degree in both groups; however, glycerol levels increased almost five times greater during the exercise in the trained subjects indicating the FFA turnover was much larger in the trained subjects. Blood glucose levels increased by an average of 11 mg% during the exercise in the trained subjects but fell by 8 mg% in the others, suggesting a greater selective uptake by the untrained subjects. Muscle glycogen depletion was 66% greater in the untrained group. These catabolic processes were independent of muscle fiber type, indicating that aerobic training increases those enzyme activities associated with FFA oxidation. Trained individuals are thus able to shift to fatty acids as the primary carbon source for the citric acid cycle, sparing glycogen during submaximal work.

No description available.

The ubiquitous distribution of the pentose molecule in nature and particularly its presence in certain enzymes and in nucleic acids emphasizes the metabolic significance of these carbohydrates. In living systems the pentoses are undergoing continuous metabolic changes. It thus appeared that investigations concerning the metabolic decomposition of the pentose molecule would be important from a comparative biochemical point of view. The advantages of a microbial system as a working model for biochemical investigations are well known. Investigations concerning pentose metabolism were, therefore, carried out with a washed bacterial cell suspension utilizing xylose as a sole substrate. Previous investigators have obtained evidence that one of the first reactions in the fermentation of pentoses was a carbon bond cleavage resulting in the production of a C₃ and a C₂ fragment. The importance of the C₂ fragment in enzymatic systems is well recognized and it thus seemed plausible that investigations on bacterial pentose fermentations would be of significant value to the field of intermediary metabolism. Preliminary investigations revealed that cells of Escherichia coli K-12 grown in the presence of pentose possessed the ability to ferment pentoses in the nonproliferating cell state. Additional experiments concerning the anaerobic decomposition of xylose re-emphasized the metabolic importance of the C₂ fragment. In fermentations conducted at low pH, lactic acid was produced in a ratio of approximately 1.3 moles per mole of xylose fermented. Since a maximum of only 1.0 moles of lactic acid could have been derived from the C₃ portion of the xylose molecule this was taken as a priori evidence that the C₂ portion of the C₅ molecule was also involved in the formation of lactic acid. Furthermore, at low pH, there was a net fixation of C0₂ which indicated that a direct participation of C0₂ was involved in the production of lactate. There were a number of pathways by which lactate could have been formed from C₂ and carbon tracer experiments were conducted in order to determine the main mechanism of C₂⟶C₃ in this system. These experiments demonstrated that C₂ tracers (C¹⁴H₃C00H and C¹⁴H₃CH₂0H) were converted to the CH₃-CH0H-portion of lactate while C₁ tracers (c¹³0₂ and HC¹⁴OOH) appeared in the lactate carboxyl. This latter piece of evidence was a further indication that lactate was formed via a C₂ + C₁ condensation. This condensation functioned at pH 7.4 as well as at pH 5.3. With C¹⁴H₃C00H as tracer succinate was labeled exclusively in the methylene carbons and it was concluded that the lactate was not in close equilibrium with succinate. The production of lactate via C₂ + C₁ condensation further emphasizes the general role of this reaction in intermediary metabolism. The fact that C₂ produced from pentoses apparently can be converted to C₃ also provides a mechanism for the conversion of pentoses into hexoses and vice versa. / Ph. D.

by Sonia, Tze Yan Lo. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1999. / Includes bibliographical references (leaves 132-147). / Abstracts in English and Chinese. / Acknowledgments --- p.i / Abstract --- p.ii / Table of Content --- p.iii / List of Figures --- p.ix / List of Tables --- p.xiii / List of Abbreviations --- p.xv / Terminology --- p.xvii / Chapter 1. --- Introduction --- p.1 / Chapter 1.1 --- Objectives of sewage treatment process --- p.1 / Chapter 1.1.1 --- Types of treatment --- p.1 / Chapter 1.1.2 --- Activated sludge process --- p.2 / Chapter 1.1.3 --- Functioning of activated sludge process --- p.2 / Chapter 1.2 --- Common microbially mediated solid separation problems --- p.4 / Chapter 1.3 --- Bacterial foaming --- p.4 / Chapter 1.4 --- Factors enhancing foam production --- p.5 / Chapter 1.4.1 --- Substrates present in sewage --- p.6 / Chapter 1.4.2 --- Operating conditions --- p.8 / Chapter 1.4.3 --- Overpopulation of foaming bacteria --- p.8 / Chapter 1.5 --- Bacteria reported for foaming --- p.9 / Chapter 1.5.1 --- Foaming bacteria reported in different countries --- p.9 / Chapter 1.5.2 --- Nocardia Biology --- p.10 / Chapter 1.6 --- Metaboilsm of hydrophobic substances in sewage --- p.11 / Chapter 1.6.1 --- Metabolism of alkanes --- p.11 / Chapter 1.6.2 --- Metabolism of grease and oils --- p.11 / Chapter 1.6.3 --- Functions of lipids in the formation of bacterial foam --- p.11 / Chapter 1.7 --- Competition between floc-formers and foam-formers --- p.12 / Chapter 1.7.1 --- Interactions between microbial populations in activated sludge process --- p.12 / Chapter 1.7.2 --- Monod relationship and kinetic selection --- p.15 / Chapter 1.7.3 --- Effects of grease and oils in dominance of foaming bacteria --- p.17 / Chapter 1.8 --- Suggested mechanisms for bacterial foaming --- p.18 / Chapter 1.8.1 --- Mechanism suggested in early stage --- p.18 / Chapter 1.8.2 --- Froth flotation theory --- p.18 / Chapter 1.9 --- Problems from foaming --- p.21 / Chapter 1.10 --- Control of filamentous bacterial foaming --- p.22 / Chapter 2. --- Objectives of the study --- p.26 / Chapter 3. --- Materials and Methods --- p.27 / Chapter 3.1 --- Sample collection --- p.27 / Chapter 3.2 --- Isolation of major foaming and non-foaming bacteria --- p.27 / Chapter 3.2.1 --- Isolation of foaming bacteria --- p.27 / Chapter 3.2.2 --- Isolation of non-foaming bacteria --- p.30 / Chapter 3.3 --- "Physiological studies on type strain Nocardia amarae ATCC 27810, isolated major foaming bacterium, Nocardia sp. CU-2 and non- foaming bacterium, Aeromonas sp. CU-1" --- p.31 / Chapter 3.4 --- Effects of fatty acids on growth kinetics of Nocardia sp. CU-2 and Aeromonas sp. CU-1 in pure culture --- p.32 / Chapter 3.5 --- Effects of fatty acids on growth yields of Nocardia sp. CU-2 and Aeromonas sp. CU-1 in pure culture --- p.34 / Chapter 3.6 --- Effects of fatty acids on growth yields of Nocardia sp. CU-2 and Aeromonas sp. CU-1 in mixed culture --- p.37 / Chapter 3.7 --- Effect of fatty acids on the propensity of foam formation of Nocardia sp. CU-2 growing with different fatty acids --- p.38 / Chapter 3.8 --- Effects of fatty acids on hydrocarbon affinity (HA) of Nocardia sp CU-2 --- p.39 / Chapter 3.9 --- "Effects of fatty acids on the filamentous growth, nocardial growth, foaming abilities and settling abilities of activated sludge in batch cultures of foaming and non-foaming samples" --- p.43 / Chapter 4. --- Results --- p.48 / Chapter 4.1 --- Isolation of foaming and non-foaming bacteria --- p.48 / Chapter 4.1.1 --- Isolation of foaming bacteria --- p.48 / Chapter 4.1.2 --- Isolation of non-foaming bacteria --- p.48 / Chapter 4.2 --- "Physiological studies on type strain Nocardia amarae ATCC 27810, isolated major foaming bacterium, Nocardia sp. CU-2 and non- foaming bacterium, Aeromonas sp. CU-1" --- p.56 / Chapter 4.3 --- Effects of fatty acids on growth kinetics of Nocardia sp. CU-2 and Aeromonas sp. CU-1 in pure culture --- p.56 / Chapter 4.4 --- Effects of fatty acids on growth yields of Nocardia sp. CU-2 and Aeromonas sp. CU-1 in pure culture --- p.60 / Chapter 4.4.1 --- Effects of fatty acids on Nocardia sp. CU-2 --- p.77 / Chapter 4.4.2 --- Effects of fatty acids on Aeromonas sp. CU-1 --- p.77 / Chapter 4.5 --- Effects of fatty acids on growth yields of Nocardia sp. CU-2 and Aeromonas sp. CU-1 in mixed culture --- p.78 / Chapter 4.6 --- Effect of fatty acids on the propensity of foam formation of Nocardia sp. CU-2 growing with different fatty acids --- p.78 / Chapter 4.7 --- Effects of fatty acids on hydrocarbon affinity (HA) of Nocardia sp CU-2 --- p.83 / Chapter 4.8 --- "Effects of fatty acids on the filamentous growth, nocardial growth, foaming abilities and settling abilities of activated sludge in batch cultures of foaming and non-foaming samples" --- p.103 / Chapter 4.8.1 --- The filamentous growth of activated sludge --- p.103 / Chapter 4.8.2 --- Nocardial count --- p.103 / Chapter 4.8.3 --- Foam ratings --- p.107 / Chapter 4.8.4 --- Sludge settling ability --- p.107 / Chapter 5. --- Discussion --- p.114 / Chapter 5.1 --- "Physiological studies on type strain Nocardia amarae ATCC 27810, isolated major foaming bacterium, Nocardia sp. CU-2 and non- foaming bacterium, Aeromonas sp. CU-1" --- p.114 / Chapter 5.2 --- Effects of fatty acids on growth kinetics of Nocardia sp. CU-2 and Aeromonas sp. CU-1 in pure culture --- p.114 / Chapter 5.2.1 --- Inhibition effects of MC fatty acids on growth of Nocardia sp. CU-2 --- p.115 / Chapter 5.2.2 --- Effects of fatty acids on specific growth rates --- p.115 / Chapter 5.2.3 --- Length of lag phase --- p.115 / Chapter 5.2.4 --- Kinetic selection of Nocardia sp. CU-2 and Aeromonas sp. CU-1 --- p.116 / Chapter 5.3 --- Effects of fatty acids on growth yields of Nocardia sp. CU-2 and Aeromonas sp. CU-1 in pure culture --- p.117 / Chapter 5.3.1 --- Growth of Nocardia sp. CU-2 and Aeromonas sp. CU-1 in different media --- p.117 / Chapter 5.3.2 --- "Effects of fatty acids on Nocardia sp, CU-2" --- p.118 / Chapter 5.3.3 --- Effects of fatty acids on Aeromonas sp. CU-1 --- p.119 / Chapter 5.4 --- Effects of fatty acids on growth yields of Nocardia sp. CU-2 and Aeromonas sp. CU-1 in mixed culture --- p.119 / Chapter 5.4.1 --- Effects of fatty acids in NB --- p.119 / Chapter 5.4.2 --- Effects of fatty acids in MM --- p.120 / Chapter 5.4.3 --- Effects of fatty acids in SS --- p.121 / Chapter 5.5 --- Effect of fatty acids on the propensity of foam formation of Nocardia sp. CU-2 growing with different fatty acids --- p.122 / Chapter 5.6 --- Effects of fatty acids on hydrocarbon affinity (HA) of Nocardia sp CU-2 --- p.122 / Chapter 5.6.1 --- Differences in HA of Nocardia sp. CU-2 among three hydrocarbons --- p.122 / Chapter 5.6.2 --- Differences in HA of Nocardia sp. CU-2 among three different media --- p.123 / Chapter 5.6.3 --- Effects of fatty acids on HA of Nocardia sp. CU-2 --- p.123 / Chapter 5.7 --- "Effects of fatty acids on the filamentous growth, nocardial growth, foaming and settling abilities of activated sludge in batch cultures" --- p.124 / Chapter 5.7.1 --- Abundance of filamentous microorganisms in activated sludge --- p.124 / Chapter 5.7.2 --- Nocardial count --- p.124 / Chapter 5.7.3 --- Foam ratings --- p.125 / Chapter 5.7.4 --- Sludge settling ability --- p.126 / Chapter 6. --- Conclusion --- p.127 / Chapter 7. --- Summary --- p.129 / Chapter 8. --- References --- p.132

No description available.

Bacillus thuringiensis and .:scherichia coli were grown in submerged cultures in the presence of 1-014 labeled decanoic, palmitic and oleic acids and 2-C14 labeled malonic acid. The bacteria were harvested by centrifugation and fractionated by published methods. Cellular constituents were separated and identified by chromatographic techniques. Radioactivity was determined by liquid scintillation spectrometry and through the use of a radiochromatogram scanner.The bacteria incorporated all the fatty acids added to the medium but showed a preference for the longer chained compounds. The organisms incorporated 1-014 palmitic acid into mostly phospholipids and also into free fatty acids and neutral lipids. At least 90% of the incorporated palmitate remained as palmitic acid. Elongation to stearic acid was demonstrated by B. thuringiensis. The label from 1-014 palmitic acid was retained over several generations by both test organisms.Ball State UniversityMuncie, IN 47306

No description available.

Germinating pea (Pisum sativum L.) roots were divided into five sequential 0.5 cm segments from the root tip. Pooled segments were analyzed for their protein, starch and lipid content as an indirect indication of plastid function. Fresh weights of root segments were lowest in the tips (4.45mug per segment) and progressively higher up to the fifth segment (11.09mug per segment). Total protein, starch and lipid content, on a per segment basis, were all highest in zone 1 (tip segment) and progressively lower up to zone 5. Plastids were isolated from each of the five root segments and analyzed for their capacity for lipid biosynthesis under several different in vitro conditions. Collectively, the observations presented here suggest that the relative contributions of plastids to the overall physiology of germinating pea roots gradually diminishes as root development proceeds, and that plastids isolated from progressively older root zones have increased capacity for glycolytic and/or pentose phosphate metabolism. (Abstract shortened by UMI.)

The interaction between the glycolytic metabolism and fatty acid and glycerolipid biosynthesis in pea root (Pisum sativum L.) plastids was assessed in this study. When various glycolytic intermediates were used to substitute for the APT requirement for fatty acid synthesis from acetate, phosphoenolpyruvate, 2-phosphoglycerate, fructose-6-phosphate and glucose-6-phosphate each gave 48, 17, 23 and 17%, respectively, of the ATP-control activity. Similarly, in the absence of exogenously supplied ATP, the optimized triose-phosphate shuttle, which consists of 2 mM dihydroxyacetone phosphate, 2 mM oxaloacetic acid and 4 mM inorganic phosphate, gave up to 44% the ATP-control activity in promoting fatty acid synthesis from acetate. These results suggest that 3-phosphoglycerate kinase and pyruvate kinase in these plastids can function in intraplastidic ATP production through substrate level phosphorylation. However, in all cases, exogenously supplied ATP gave the greatest rates of fatty acid and glycerolipid synthesis. Radiolabeled pyruvate, glucose, glucose-6-phosphate, and malate in comparison to acetate were all variously utilized for fatty acid and glycerolipid biosynthesis by the root plastid. At the highest concentrations tested (3-5 mM), the rates of incorporation of pyruvate, glucose-6-phosphate and acetate into fatty acids were 183, 154, 125 nd 99 nmol $ rm cdot h sp{-1} cdot mg sp{-1}$, respectively. Malate was the least effective precursor, giving less than 55 nmol $ rm cdot h sp{-1} cdot mg sp{-1}$. Acetate incorporation was approximately 55% dependent on exogenously supplied reduced nuclotides (NADPH and NADH), whereas the utilization of the remaining precursors was only approximately 10-20% dependent on NAD(P)H. These results indicate that the entire pathway of carbon flow from glycolysis, including pyruvate dehydrogenase (PDHase), to fatty acids is operating in pea root plastids. Further, the intraplastidic glycolytic pathway plays an important role in provi

The effect of fatty acids on energy metabolism has been shown to be dependent on their acyl structure. In humans, following short term feeding, medium chain triglycerides (MCT) have been shown to increase the thermic effect of food and fat oxidation as compared to long chain triglycerides (LCT). Short term results in animals have been comparable. In longer term, animal studies, MCT vs. LCT have resulted in less weight gain during overfeeding or refeeding after weight loss. However, observations of the longer term effects of MCT in humans beyond 7 days are sparse and inconclusive. Hence, the objective of the thesis was to examine the effects of MCT vs. LCT on total energy expenditure, its components basal metabolic rate and thermic effect of food, and on substrate oxidation, including both exogenous and endogenous fat oxidation for a period of one week, following one week of prefeeding. Twelve healthy college aged women were fed eucaloric 14 days diets enriched with either MCT or LCT in a randomized cross over design, with a two week washout period. Doubly labelled water, respiratory gas exchange analysis, and 1-13C labelled myristic, palmitic, and stearic acids were used to measure total energy expenditure, components of energy expenditure, and endogenous long chain fatty acid oxidation, respectively. The presence of MCT in the diet significantly increased endogenous oxidation of labelled long chain fatty acids following 14 days of feeding, while the presence of LCT did not. Respiratory gas exchange analysis showed significantly increased basal metabolic rate on day 7 of MCT vs. LCT feeding, but this effect of diet was reduced to a trend by day 14. Dietary treatment did not result in significant differences in total energy expenditure during the second week of feeding. These results suggest that, after two weeks of feeding, MCT continue to affect energy metabolism through increased endogenous fat oxidation and a suggestion of heightened basal metabolic rate, but