Thesis (MS)--Montana State University--Bozeman, 2009. / Typescript. Chairperson, Graduate Committee: Robin Gerlach. Includes bibliographical references (leaves 123-130).

Thesis (M.S.)--West Virginia University, 2007. / Title from document title page. Document formatted into pages; contains x, 78 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 71-78).

Thesis (Ph.D.)--Duquesne University, 2005. / Title from document title page. Abstract included in electronic submission form. Includes bibliographical references and abstracts.

The potential for using RMP (refiner mechanical process) pulp mill fibre waste as a soil amendment was investigated by determining levels of net carbon mineralization. Under optimum conditions (laboratory incubation study), the pulp fibre waste, being a relatively homogeneous substrate, was found to mineralize at one rate of -0.0078 d⁻¹. In field applications the rate of net mineralization was slower, with rates of -0.0034 d⁻¹ and -0.0037 d⁻¹, as determined by soil respiration and litter bag trials, respectively. A loading effect was noted for this amendment, where increasing the levels of application was found to cause decreases in the mineralization rate. Using pulp fibre waste in forest landing rehabilitation appears to increase the levels of microbial activity in the surface horizon. The higher levels of productivity should lead to improvements in soil structure, and would be a better alternative to only tilling and fertilizing the soil. / Land and Food Systems, Faculty of / Graduate

Model peptides were designed, synthesized and conducted a detailed structure-property study to unravel the molecular mechanism of goose eggshell calcification. The peptides were designed based on the primary structural features of the eggshell matrix proteins ansocalcin and OC-17. In vitro CaCO₃ crystal growth experiments in presence of these peptides showed calcite crystal aggregation as observed in the case of the parent protein ansocalcin. The structure of these peptides in solution was established using intrinsic tryptophan fluorescence studies and quasi-elastic light scattering experiments. The structural features are correlated with observed results of the in vitro crystallization studies. / Singapore-MIT Alliance (SMA)

Microbial action on particulate chitin was analyzed in an eastcentral Indiana borrow pit lake. Experiments were conducted to determine the effects of water depth, particle size, mesh size of nylon bag containing chitin, and season on the decomposition process. The majority of chitinolytic bacteria isolated were classified as actinomycetes and pseudomonads. Results indicate that the sediment-water interface is the most active site of chitin mineralization in the lake environment. The samples seeded during summer showed the fastest rate of decomposition with greater than 50% weight loss after two weeks and greater than 95% weight loss after 7 weeks incubation in situ. The highest rate of decomposition (43.6 mg/g/day) occurred during this period. Samples seeded during the spring showed considerably slower activity with only a 25`o weight loss after 9 weeks incubation in situ. Fall samples showed a 30% weight loss after 9 weeks incubation in situ. The rate of degradation was highly correlated with water temperature. Significantly higher rates were-.noted with smaller particle size but no significant difference was evidenced with varying mesh size fran 10 to 100 in. The majority of chitinolytic bacteria isolated were Gram negative; Pseudanonas, Chranobacterium, Flavobacterium, and Serratia spp. Gram positive organisms showing chitin hydrolysis were predominantly actinomycetes. An active chitinolytic culture of Pseudcmonas sp. was used for enzyme studies. This culture was purified using (NH4)2SO4 precipitation, anion exchange chromatography and hydroxylapatite chromatography.Ball State UniversityMuncie, IN 47306

Thesis (Ph. D.)--University of Washington, 2003. / Vita. Includes bibliographical references (leaves 96-105).

Recently, self-healing applications of cement-based materials have received a lot of interest. One major area of interest with respect to self-healing applications in cement-based systems focuses on using biomineralization processes. Biomineralization is biochemical process in which microorganisms stimulate the formation of minerals. The existing research on biomineralization in cement-based systems has showed promising results and the studies suggest that biomineralization could be a useful approach for remediation of cracks on the surface of concrete. This dissertation presents the results of an intensive study undertaken to understand the influence of vegetative bacteria, specifically Sporosarcina pasteurii (S. pasteurii), when it is incorporated within cement paste. Vegetative S. pasteurii cells were suspended in a urea-yeast extract medium and this medium was mixed with cement. The influence of the vegetative S. pasteurii cells on Portland cement paste properties, such as compressive strength, hydration kinetics, and setting time was evaluated. It was determined that the hydration kinetics was highly influenced when the bacterial medium was used to prepare cement paste, and severe retardation was observed. It was also observed that an increase in calcium carbonate precipitation, particularly calcite, occurred within cement paste when the bacterial medium was used. Furthermore, use of the bacterial medium resulted in reducing the porosity and increasing the compressive strength of the hardened paste. Ex-situ culture experiments were conducted to determine the impact of pH and calcium concentration on the morphology of calcium carbonate precipitate; the results indicated that the morphology of the precipitate was more influenced by calcium concentration. A key focus of this dissertation was to examine the viability of the vegetative cells that were inoculated in cement paste. Viable S. pasteurii cells were found to be present in hardened cement paste samples that were as old as 330-days, and 50% of the viable cells detected were defined as vegetative cells. At last, the use of including internal nutrient reservoirs as a means to extend the viability of the bacterial cells within hardened cement paste was explored. The results showed that the percentage of vegetative cells remaining was affected when internal nutrient reservoirs was incorporated into the system. / text

Atmospheric carbon dioxide (CO2) has increased due to human activity from a pre-industrial value of about 280 ppm to the present level of 399 ppm. The ocean acts as an important natural carbon sink that effectively removes 1/3 of this anthropogenic CO2 from the atmosphere, buffering global warming effects. However, the dissolution of CO2 causes a dramatic change in seawater chemistry and ultimately results in the phenomenon commonly known as "ocean acidification" (OA). As a consequence, the pH value and the saturation states for calcium carbonate decline in the surface seawater, posing a threat to calcareous marine organisms that build their shells using exquisite biomineralization mechanisms. Biological minerals produced by marine organisms are compositionally and structurally more complex than geological minerals. Although changes in biomineral formation in response to OA has been intensively investigated, the features of calcified products in terms of their composition, architectures and mechanical properties have been overlooked in climate change research. The tubeworm is a favourite marine model organism in larval biology. Its life cycle is well understood hence provides a good opportunity to study OA impacts on the stochastic early life. In addition, the model enables comprehensive observation of the sophisticated biomineralization events. In this thesis, four studies on the biomineralization of Hydroides elegans, using a multidisciplinary collaborative approach combining larval biology and material science were conducted. (1) The tube mineral composition at different juvenile stages (4, 11, 18, 25 days) were characterized. (2) The impacts of different predicted OA scenarios (pH 8.1, 7.9, 7.6, and 7.4) on the resultant calcification products were compared. (3) A multiple-stressor investigation of OA (pH 8.1 and 7.8), reduced salinity (33 ‰ and 27 ‰) and increased temperature (25 °C and 29 °C) was conducted to further determine the more environmentally realistic OA impacts. (4) Calcification sites were examined by using a microscopy approach The main findings from each study were: (1) H. elegans produced both calcite and aragonite forms of CaCO3, which have distinctive physical and chemical properties. Thus, the tubeworm serves as an interesting model for studying OA impacts on biomineralization. The early juvenile stages are expected to be more sensitive to OA than the later life stages because the juvenile tubes are rich in aragonite and amorphous calcium carbonate. (2) Under experimental OA conditions, the composition and architecture of the tube structures were adversely affected, ultimately producing tubes with weaker mechanical properties. (3) Warming appeared to strengthen the tube structures and mitigated the adverse OA effects. (4) Calcification sites correlated to regions with higher pH values of 8.5 - 9.0. These regions may be sensitive to OA and should be further analyzed to study the mechanisms of OA impacts on calcification. This series of experiments study biomineralization and larval biology using a variety of modern multidisciplinary approaches provided new insights into the impacts of OA and climate change impacts on marine organisms and also helped us to project which species might adapt or succumb to future scenarios. / published_or_final_version / Biological Sciences / Doctoral / Doctor of Philosophy

Biomimetics is defined as an approach in which naturally occurring materials processes are mimicked in laboratory situations. The ultimate goal is to develop synthetic analogues of naturally occurring materials such as bone and teeth, classified as biocomposites, which possess similar chemical and mechanical properties. The work presented here provides the initial work in furthering the progress of biomimetic materials processing.The first element of the work utilizes molecular imprinting as a selective recognition, or sensing tool, for detection of low molecular weight organic molecules. Molecular imprinting is a phenomenon in which crosslinked synthetic polymers exhibit selective binding towards small organic molecules. Initial work in the field was done in which numerous processing steps were involved with bulk polymer samples while the achievement here lies in the development of molecular imprinted polymer films which greatly facilitate the processing and characterization. Molecularly imprinted polymers are sometimes referred to as artificial antibodies due to the selective binding aspects that are highly analogous to natural antibodies.Additional work involves transforming the recognition aspects of molecular imprinting into a biomineralization analogue. Biomineralization is the process in which organisms convert freely soluble minerals (namely calcium carbonates and calcium phosphates) into solid parts, such as bones and teeth, at ambient conditions via the influence of organic molecules such as proteins and carbohydrates. The molecular imprinting approach with biomineralization led to limited success but formed the foundation for a more detailed study into the effects of small organic functional groups (COOH-, OH-) on the growth of calcium carbonates and calcium phosphates, the core components of important biocomposites such as bone.In order to study the effects of organic molecules on the calcium based crystals, a mineralization assay was developed in an agarose gel matrix for studying inhibition and growth as influenced by various organic molecule functionalities. The gel mineralization assay is a novel approach in which quantitative and qualitative data could be generated in a high throughput fashion to determine organic molecule mediation of calcium based crystal growth. Such methods provide an approach for eventually providing control in development of synthetic biocomposites with customized materials properties.