Ethanol, when mixed with gasoline, is an economical and environmentally friendly liquid fuel. Yeast cells under anaerobic conditions can ferment glucose to ethanol. However, glucose is expensive for industrial applications and starch is an economical alternative. Simultaneous cold starch hydrolysis and fermentation was investigated for ethanol production from wheat starch particles. With a view to minimize process costs while maintaining a satisfactory ethanol yield, both a recombinant yeast cell and an inexpensive medium were tested for their fermentation abilities. Initially, NRRL Y132 strain was compared to Muntons yeast for their abilities to produce ethanol from glucose. Both the wild-type and the recombinant NRRL Y132 strains were cultured on soluble starch to determine if the plasmid bearing strain could produce ethanol without the addition of -amylase. Finally, Muntons yeast was cultured on starch particles using both expensive and inexpensive media. Sequential hydrolysis and fermentation runs were performed using the inexpensive medium, with hydrolysis carried out at 30°C, 37.5°C, 45°C and 52.5°C. The wild-type, NRRL Y132 strain grew faster and produced more ethanol than Muntons yeast when cultured on glucose. Compared to the wild-type strain, the recombinant NRRL Y132 strain did not show enhanced ethanol production from soluble starch. The results of the simultaneous hydrolysis and fermentation runs showed that the ethanol yields for runs performed in expensive medium (0.41, 0.38 and 0.42 g ethanol / g glucose) were slightly lower than those for runs performed in the inexpensive medium (0.46, 0.44 and 0.43 g ethanol / g glucose). The growth rates for the expensive and inexpensive media runs were comparable. Hence, it was concluded that the inexpensive medium can be used for ethanol production from starch particles with good ethanol productivities. For the sequential hydrolysis and fermentation runs, it was observed that the growth rates (0.11, 0.10, 0.10 and 0.11 h-1) as well as the ethanol yields (0.44, 0.37, 0.44 and 0.39 g ethanol / g glucose) were similar in spite of the four different hydrolysis temperatures. Therefore, it was concluded that increasing the temperature above 30°C for enhancing starch particle hydrolysis does not increase fermentation productivity significantly.

Ethanol, when mixed with gasoline, is an economical and environmentally friendly liquid fuel. Yeast cells under anaerobic conditions can ferment glucose to ethanol. However, glucose is expensive for industrial applications and starch is an economical alternative. Simultaneous cold starch hydrolysis and fermentation was investigated for ethanol production from wheat starch particles. With a view to minimize process costs while maintaining a satisfactory ethanol yield, both a recombinant yeast cell and an inexpensive medium were tested for their fermentation abilities. Initially, NRRL Y132 strain was compared to Muntons yeast for their abilities to produce ethanol from glucose. Both the wild-type and the recombinant NRRL Y132 strains were cultured on soluble starch to determine if the plasmid bearing strain could produce ethanol without the addition of -amylase. Finally, Muntons yeast was cultured on starch particles using both expensive and inexpensive media. Sequential hydrolysis and fermentation runs were performed using the inexpensive medium, with hydrolysis carried out at 30°C, 37.5°C, 45°C and 52.5°C. The wild-type, NRRL Y132 strain grew faster and produced more ethanol than Muntons yeast when cultured on glucose. Compared to the wild-type strain, the recombinant NRRL Y132 strain did not show enhanced ethanol production from soluble starch. The results of the simultaneous hydrolysis and fermentation runs showed that the ethanol yields for runs performed in expensive medium (0.41, 0.38 and 0.42 g ethanol / g glucose) were slightly lower than those for runs performed in the inexpensive medium (0.46, 0.44 and 0.43 g ethanol / g glucose). The growth rates for the expensive and inexpensive media runs were comparable. Hence, it was concluded that the inexpensive medium can be used for ethanol production from starch particles with good ethanol productivities. For the sequential hydrolysis and fermentation runs, it was observed that the growth rates (0.11, 0.10, 0.10 and 0.11 h-1) as well as the ethanol yields (0.44, 0.37, 0.44 and 0.39 g ethanol / g glucose) were similar in spite of the four different hydrolysis temperatures. Therefore, it was concluded that increasing the temperature above 30°C for enhancing starch particle hydrolysis does not increase fermentation productivity significantly.

published_or_final_version / Civil and Structural Engineering / Master / Master of Philosophy

No description available.

Fourteen varieties of wheat grown in western Canada were assessed for differences in starch content and structure. Physicochemical properties of starch such as amylopectin to amylose ratio, starch granule morphology, and thermal and pasting properties were all found to vary significantly between varieties. Enzymatic susceptibility was measured using industrial α-amylase to hydrolyze gelatinized starches and resultant reducing sugar content ranged from ~407−500mg glucose equivalents per gram starch, indicating different patterns of oligosaccharide chain lengths present after hydrolysis. During fermentation striking differences in glucose generation were observed, the high glucose cohort averaged 1.21 g/g-starch for the initial time point, compared to a range of 0.83−1.05 g/g-starch for the low glucose cohort. In general, the pattern of glucose generation appears to be consistent with ethanol and biomass production. Correlating structural attributes with fermentation performance suggests that amylopectin to amylose ratio is the most predictive factor in the pattern of wheat starch hydrolysis.

Biopolymers have been recently received more and more attention as a renewable substitute for traditional petroleum-based materials. Products made from petroleum-based materials typically cannot be recovered, with long term ramifications in sustainability and environmental concerns. Biopolymers such as starch are renewable, environmentally-friendly alternatives which have found additional use beyond their traditional roles as food substances as a biopolymer material, replacing their petroleum-based counterparts with comparable physical properties but also featuring long-term sustainable use. One such use is for starch to replace latex as a paper binder. Starch nanoparticles have seen tremendous development in use as a paper binder in place of traditional petroleum-based latexes, and other possibilities for the use of these starch nanoparticles are also being explored. Nucleic acids have long been used by Nature as a carrier of genetic information. Recent advances in technology have allowed the fine manipulation of nucleic acids to take advantage of their inherent stability for roles beyond genetics. This includes the use of nucleic acids for bio-based sensing and for immunochemistry, which takes advantage of the chemical structure of nucleic acids for practical use. In this thesis, the interactions between starch and deoxyribonucleic acid (DNA) biopolymers are investigated. The two biopolymers are found to adsorb to each other when dispersed in aqueous solution together. This can lead to the co-precipitation of the two biopolymers together out of solution in organic solvents such as ethanol. The generalizability of this interaction is explored, including its dependence on starch crosslinking, on the length and sequence of DNA, and the pH and salt concentration of the solvent. Fluorescence spectroscopy was used to characterize their interaction, supported by other similar techniques. The covalent linkage of DNA and starch is also investigated. To this end, the appropriateness of using a starch-based nanoparticle with DNA coupling for drug delivery is considered. Starch is oxidized and covalently linked with DNA used as a targeting ligand and introduced to the HeLa cancer cell line. Various fluorescence-based techniques were used to monitor this interaction.

Fourteen varieties of wheat grown in western Canada were assessed for differences in starch content and structure. Physicochemical properties of starch such as amylopectin to amylose ratio, starch granule morphology, and thermal and pasting properties were all found to vary significantly between varieties. Enzymatic susceptibility was measured using industrial α-amylase to hydrolyze gelatinized starches and resultant reducing sugar content ranged from ~407−500mg glucose equivalents per gram starch, indicating different patterns of oligosaccharide chain lengths present after hydrolysis. During fermentation striking differences in glucose generation were observed, the high glucose cohort averaged 1.21 g/g-starch for the initial time point, compared to a range of 0.83−1.05 g/g-starch for the low glucose cohort. In general, the pattern of glucose generation appears to be consistent with ethanol and biomass production. Correlating structural attributes with fermentation performance suggests that amylopectin to amylose ratio is the most predictive factor in the pattern of wheat starch hydrolysis.

Thesis (MSc)--University of Stellenbosch, 2007. / Bibliography. Also available via the Internet.

Thesis (Ph. D.)--Columbia University, 1929. / Vita. eContent provider-neutral record in process. Description based on print version record. Bibliography: p. 23.

Thesis (doctoral)--University of Helsinki, 2002. / Includes bibliographical references. Also available on the World Wide Web.