No description available.

No description available.

Oils from soybeans and catfish by-products were extracted using hexane, propane, and supercritical carbon dioxide (SCCO2). Free fatty acids (FFA), peroxide values (PV), anisidine values (AnV), total oxidation (TOTOX), induction point (IP), iodine values (IV), and 2-thiobarbituric acid reactive substance (TBARS) were all measured to analyze oxidation of these oils. The extraction yield of propane, hexane, and SCCO2 oils was 80.4, 94.5, and 90%, in respect to total lipid content. Oils extracted with SCCO2 were more oxidized than those extracted with propane and hexane; probably due to the higher temperature and longer extraction time. The IP correlated with AnV, IV, PV, and TBARS for soybean and catfish oils. These results suggest that IP is the optimum way to measure soybean and catfish oil stability.

Thesis--Auburn University, 2009. / Abstract. Includes bibliographical references.

Oxidative storage stability was conducted to determine the optimum antioxidant for the production of catfish methyl esters (CFME) for use as biodiesel. Peroxide value, anisidine value, 2-thiobarbituric reaction substances, acid value, iodine value, UV absorbance, and induction period were measured. Antioxidant, stability parameters changed over a storage time of one year when stored at 25°C. The CFME were not stable to oxidation without the addition of TBHQ. When stored at 25°C, oxidative parameters indicated that CFME was a stable product that met oxidative stability standards when TBHQ was added. When held at 80°C for 28 days, the samples with TBHQ were stable to oxidation. However, the acid value rose above the maximum at 28 days. Thus, CFME can be stable to oxidative breakdown when THBQ was added at 800 ppm, but when exposed to high temperatures, one will have to limit water or protect CFME against hydrolytic rancidity.

This thesis describes the chemistry developed during a study of novel transition metalcatalysed reactions for the synthesis of carboxylic acid derivatives. Chapter 2 describes a novel protocol for the synthesis of primary amides from alcohols in one-pot where a metal complex mediates two fundamentally different catalytic processes. An iridium catalyst has been shown to be effective for the selective rearrangement of aldoximes into primary amides. In addition, an iridium-catalysed oxidation of activated alcohols via hydrogen transfer has been developed using an alkene as formal oxidant. These reactions have been combined in a sequential process affording good yields for a range of benzylic alcohols. An improved system for the rearrangement of aldoximes into amides using a new ruthenium catalyst is described in Chapter 3. Through a systematic program of optimisation excellent selectivity was achieved for a wide range of substrates at markedly reduced catalyst loading. Chapter 4 describes the development of a ruthenium-catalysed elimination reaction for the conversion of oxime ethers into nitriles. The application of this reaction to tandem and sequential reactions has been explored, albeit with limited success. Also, a method for the ruthenium-catalysed oxidation of alcohols using an electron-deficient alkene as hydrogen acceptor is described, and its application to a tandem oxidation process with a nitrogen nucleophile demonstrated. As an extension of the concept presented in Chapter 4, tandem oxidation processes with oxygen nucleophiles are the subject of Chapter 5. This strategy has been used for the oxidation of primary alcohols to their corresponding methyl esters in one-pot, with good yields obtained for a range of substrates. The use of water as a nucleophile in such a process has also been examined.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1947. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves [92-97]).

The growth of Rhodotorula glutinis in sweet sorghum juice in three levels of three factors of temperature, carbon to nitrogen ratio and pH was evaluated. Accompanying of this growth was the generation of lipids converted to fatty acid methyl ester (FAMEs) and carotenoids. The optimized condition for maximum biomass and carotenoid accumulation was determined to be at 25C, pH of 5.5 and carbon to nitrogen ratio of 10. This condition yielded 22.7 g/L biomass with specific growth rate of 0.213 hr-1. At this condition the carotenoids generation was also maximum with 2.6 mg/gram biomass, comprising of torularhodin, beta-carotene and torulene. The accumulation of lipids following generation of biodiesel was highest at same temperature and pH but carbon to nitrogen ratio of 70, generating 96.3 mg of FAMEs/gram of biomass containing methyl ester of oleic acid, linoleic acid, palmitic acid, stearic acid and linolenic acid.

No description available.

Developing microbial systems capable of converting low cost lipids into value added products depends on the ability to acquire substrates from the growth media. Saccharomyces cerevisiae can acquire free fatty acids from the growth media and a portion of these lipids can be converted into new lipid products. However, they cannot acquire complex lipids from the growth media unless a nonspecific lipase is included. To circumvent lipase addition, we are genetically engineering S. cerevisiae to secrete a lipase into the growth media. We selected the LIP2 gene from Yarrowia lipolytica, which encodes a nonspecific lipase. Several modifications were made to the LIP2 gene to improve processing. Results identified strains secreting the most lipase. From these results, high producing strains were inserted into an oil inducible vector. Halo assays confirmed lipase secretion, while measuring the fatty acid composition confirmed triacylglycerol breakdown, and yeast uptake of the free fatty acids released.