Thesis (Ph. D.)--University of Hong Kong, 2008. / Includes bibliographical references (leaf 169-194) Also available in print.

Theses (M.S.)--Marshall University, 2007. / Title from document title page. Includes abstract. Document formatted into pages: contains viii, 37 pages. Bibliography: p. 36-37.

The effects of an organic biocide (CTN) with and without coded antioxidant (BHT) on microbial communities in SYP were assessed using terminal restriction fragment length polymorphism (T-RFLP) analyses in both field and accelerated decay laboratory studies. Ammoniacal copper quaternary (ACQ-C) was used as a positive control in the field study component, but not in the laboratory test. Field stakes were treated with 0.25 and 0.37% ammoniacal copper quat (ACQ-C), CTN (0.1 and 0.25%), CTN (0.1 and 0.25%) with 2% BHT added, 2% BHT alone, and controls were left untreated. In the field studies, preservative treatment slowed the initial colonization of wood by fungi. Higher species richness and diversity were found in non-biocidal treatments (BHT and untreated controls). Fungal communities in treated wood were different based on their species composition, but eventually became more similar to untreated controls. Preservative treatment increased richness and diversity of basidiomycete fungi, but overall presence of basidiomycetes was low compared to other fungi. Preservatives did not change the species composition of basidiomycetes compared to untreated controls. Preservative treatment initially increased bacterial richness and diversity, but over time these trends diminished to levels consistent with untreated controls. Preservatives changed the species composition of colonizing bacteria so that treated and untreated communities remained different over 15 months of soil exposure. Bacterial diversity was negatively correlated with CTN depletion at the lowest rate. In the accelerated decay laboratory test, the effects of CTN and/or BHT on bacterial, fungal, and basidiomycete communities in composted and uncomposted soil were evaluated over a 12 month period. Composted soil had less fluctuation in changing microbial diversity due to more constant moisture. The consensus of the analyses of the bacterial, fungal, and basidiomycete communities indicate that wood preservatives increased microbial species richness and diversity. Preservative treatment increased species turnover that decreased over time. Eventually, microbial communities approached a stable community structure consistent with untreated controls. Preservatives were completely degraded after 30 days exposure; however, definite changes in bacterial and fungal richness, diversity, and species composition were found. Basidiomycetes again represented the smallest portion of the microbial community involved in the overall decay process.

Call number: LD2668 .T4 1960 G35

Neste trabalho, avaliou-se a eficácia do uso da oleoresina de capsaicina, extraído das pimentas Malagueta, Red Savina e Bhut Jolokia, no tratamento da superfície de madeiras do gênero Pinus sp. com teores de umidade de equilíbrio de 12% e 0%. Os corpos de prova foram submetidos ao ataque de fungos Paecilomyces variotti e Pycnoporus sanguineus. Foi utilizado um preservante sintético conhecido comercialmente como stain para se comparar com a eficiência de preservantes naturais à base de oleoresina de capsaicina. A partir de medidas de ângulo de contato das superfícies das madeiras tratadas com o óleo de capsaicina, observou-se que a pimenta Bhut Jolokia e o preservante stain proporcionavam menor molhabilidade para a espécie de madeira estudada em ambos teores de umidade. O tratamento preservante fez com que a energia de superfície diminuísse se comparada aos valores de amostras de madeiras sem o tratamento preservante devido às contribuições polares e dispersivas. A análise estatística dos resultados, pelo método de Tukey, mostrou que não existe um grupo de resultados estatisticamente equivalente aos obtidos com a amostra testemunha (sem tratamento). As amostras de Pinus sp. a um teor de umidade 0% mostrou-se mais protegida superficialmente quando modificada com a oleoresina extraída da pimenta Bhut Jolokia e o mesmo efeito foi observado estatisticamente para o preservante stain. A técnica de Langmuir foi utilizada para melhor compreender as interações capsaicina/ergosterol, capsaicina/DPPG (dipalmitoil fosfatidil glicerol) e capsaicina/DPPG/ergosterol. A isotermas de pressão de superfície vs área por molécula se mostraram mais expandidas quando a subfase continha oleoresina de capsacina e quando comparada com as de lipídio puro (DPPG), indicando assim, a inserção da capsaicina na monocamada. Em linhas gerais, oleoresina de capsaicina extraída da pimenta Bhut Jolokia mostrou-se mais eficiente em todos os aspectos se comparada com as pimentas Red Savina e Malagueta, marcando, assim, uma potencialidade para uso como preservante natural de madeiras. / The present study evaluated the effectiveness of capsaicin oleoresin extracted from Malagueta, Red Savina and Bhut Jolokia peppers in the surface treatment of Pinus sp. with moisture contents of 12% and 0%. The samples were submitted to the attack of Paecilomyces variotti and Pycnoporus sanguineus fungus. A synthetic wood preservative, that is commercially known as stain, was used to compare the effectiveness of natural preservatives based on capsaicin oleoresin. From contact angle measurements for wood surfaces treated with capsaicin oleoresin, it was obtained that Bhut Jolokia pepper and stain preservatives have provided worse wettability for wood samples at both moisture contents. The preservative treatment caused a decrease in the surface energy when compared to the samples without preservative treatment due to polar and dispersive contributions. Statistical analysis for the results by using the Tukey method showed that there is not a group of results that are statistically equivalent to those obtained for the control samples (without treatment). Pinus sp. samples at a moisture content of 0% showed to be more surface protected after being modified with the oleoresin extracted from Bhut Jolokia; the same effect was observed statistically for stain. The Langmuir technique was used to better understand interactions among capsaicin/ergosterol, capsaicin/DPPG (dipalmitoyl phosphatidyl glycerol) and capsaicin/DPPG/ergosterol. Surface pressure vs. area per molecule isotherms appeared to be even more extended when the subphase contained capsaicin oleoresin instead of pure lipid (DPPG), thus indicating the inclusion of capsaicin into the monolayer. In general, the capsaicin oleoresin extracted from Bhut Jolokia proved to be more efficient in all the aspects of characterization when compared to Red Savina and Malagueta highlighting its potential for use as a natural wood preservative.

A lactoferrina bovina, descoberta em 1939, é uma glicoproteína que se liga reversivelmente a dois íons férricos, sendo capaz de seqüestrá-los de certos patógenos ou do meio, promovendo redução do crescimento microbiano ou se ligar as suas paredes celulares resultando na permeabilização. A lactoferrina vem ganhando notoriedade nas pesquisas, pois investigações têm descrito sua atividade in vitro frente a diversos microrganismos. Em razão desta propriedade, a mesma poderia ter aplicação nas indústrias cosmética e alimentícia, como um conservante natural. Embora alguns conservantes já estejam consagrados na literatura, os mesmos têm sido relacionados com o desencadeamento de reações alérgicas e de sensibilização, motivando a procura do conservante ideal. O objetivo deste trabalho foi avaliar a utilização da lactoferrina como conservante em formulações semi-sólidas tópicas para usos cosmético e farmacêutico, bem como verificar as estabilidades física e físico-química. Com esta finalidade, três diferentes concentrações de lactoferrina foram incorporadas nos cremes não-iônico e aniônico, gel e gel-creme. A atividade da lactoferrina foi avaliada através do teste de eficácia conservante, sendo que as formulações foram contaminadas com concentrações conhecidas dos microrganismos Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Candida albicans e Aspergillus niger, com posterior contagem do número de Unidades Formadoras de Colônias (UFC), em placas de Petri, nos tempos zero, 2, 4, 6, 12, 24, 48 e 72 horas, bem como em 7, 14, 21 e 28 dias. Para estudo das estabilidades, as formulações foram avaliadas nos tempos zero, 15, 30, 60, 90, 150 e 180 dias, nas temperaturas de 4°, 25° e 40°C. A estabilidade físico-química foi avaliada através das características macroscópicas, estabilidade à centrifugação, pH, densidade e consistência. A estabilidade física, por meio da determinação da viscosidade e comportamento reológico. Os resultados obtidos, nas condições experimentais deste trabalho, permitiram inferir que a lactoferrina bovina não provocou alteração significativa nas estabilidades física e físico-química das formulações estudadas. Quanto à eficácia da lactoferrina, a mesma não pode ser classificada como substância dotada de atividade conservante, pois não atendeu às exigências preconizadas em compêndios oficiais, frente aos microrganismos estudados. Mesmo não tendo atendido às exigências oficiais como conservante, mostrou-se efetiva frente à levedura Candida albicans, nas formulações do creme não-iônico e gel de hidroxietilcelulose. No entanto, estudos posteriores poderão avaliar a associação da lactoferrina a outros conservantes, buscando sinergismo entre eles, conseqüentemente, podendo diminuir as reações adversas e sensibilizações no usuário. / The bovine lactoferrin, discovered in 1939, is a glycoprotein that connects itself reversibly to two ions of iron being able to kidnap them from certain pathogens or from the environment promoting reduction of the microbial growth or, resulting in permeability if connected to its cellular walls. Lactoferrin has become important in researches because investigations have described its activity in vitro before many microorganisms. Due to this property, lactoferrin could be applied in cosmetic and food industries as a natural preservative. Even though some preservatives are already acclaimed in literature, lactoferrin has been related to the unleashing of allergic reactions and sensibility, motivating the search for the preservative. The goal of this paper was to evaluate lactoferrin as a preservative in semi-solid topic formulations for cosmetic and pharmaceutical uses as to verify the physical and physical-chemical stabilities. On this purpose, three different lactoferrin concentrations were incorporated in non-ionic and anionic creams, gel and gel-cream. Lactoferrin\'s performance was evaluated through testing the efficiency of the preservative, being that the formulations were contaminated by known concentrations of the microorganisms Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Candida albicans e Aspergillus niger, with posterior counting of the number of Former Colony Units (FCT), in Petri plates, on times zero, 2, 4, 6, 12, 24, 48 and 72 hours, as well as 7, 14, 21, 15, 30, 60, 90, 150 and 180 days, in temperatures of 4º, 25º and 40ºC. The physical-chemical stability was evaluated through the macroscopic characteristics,stability to centrifugation, pH, density and consistency. The physical stability through the determination of viscosity and reologic behavior. The results, in the experimental conditions of this paper, allowed inferring that the bovine lactoferrin didnt\'s provoke significant alteration in the physical and physical-chemical stabilities in the studied formulations. As to the efficiency of lactoferrin, it canot be classified as a substance endowed with preservative activity because it didn\'t reach the extolled demands in official compendiums before the studied microorganisms. Although it didn’t reach the official demands as a preservative, lactoferrin showed itself effective before the yeast Candida albicans on the formulations of the non-ionic cream and hidroxiethyl celulose gel. However, posterior studies will be able to evaluate the association of lactoferrin to other preservatives, seeking synergism between them, being able to consequently diminish the adverse reactions and sensibilities in the user.

Parabens have been used as antimicrobial preservatives in multiple different types of products for decades, however relatively recent studies have caused concern as to whether their wide-use could be potentially harmful. The following paper reviews the extensive areas of human exposure, from mother to fetus, infants via breast milk, baby and child care products through adult personal care products, and other environmental sources. The potential impacts on human health are also discussed. Parabens predominantly impact biological systems as an endocrine disruptor not only by binding to the human Estrogen Receptor directly, but increasing the availability of naturally occurring 17β-estradiol, further potentiating the effect. Alternative antimicrobial preservatives are also discussed, along with their efficacies and potential health concerns. Common alternatives found in personal care products include phenoxyethanol, methylisothiazolinone, and formaldehyde releasers. Additionally, weak organic acids and plant-derived essential oils are also used in personal care products, but tend to be added more so to food products to prevent the growth of spoilage bacteria, fungi and mold. The potential for these alternatives to replace the use of parabens in personal care products, our greatest area of exposure, is very promising. If parabens in personal care products were replaced with a safe and effective alternative, then the other areas of environmental exposure would likely be negligible to produce any harm on society. Future investigation into the nuances of the various plant-derived essential oils and effective formulations for preservation, is likely the most promising solution, due to their mostly harmless nature. Lastly, the discussion of proposed future research in order to lead to a more definitive connection between paraben exposure and adverse health effects is presented.

In this research, initial studies were done to determine the effect of various methods of presentation involving chemical preservatives, water activity ($ rm a sb{w}$), and modified atmosphere packaging (MAP) on mold growth in an agar model system. Results showed that preservatives could completely inhibit mold growth for 2-40d depending on concentration and pH used. Gas packaging (60% or 80% CO$ sb2$), oxygen absorbents, alone or in combination with potassium sorbate, could also inhibit mold growth for $>$40d at ambient storage temperature using a Response Surface Methodology (RSM) approach. / The effects of various methods of applying potassium sorbate into pizza crusts via direct incorporation into the batter, surface spraying, and impregnation of packaging material with potassium sorbate to control mold spoilage of pizza crusts were also investigated. Results showed that the antimicrobial effect of potassium sorbate was negligible when the packaging material was impregnated with the inhibitor but more pronounced when it was incorporated directly into the dough or sprayed onto the product's surface. The inhibitory effect of potassium sorbate increased as both the pH and the inoculum level decreased. / Shelf life studies using low concentrations of potassium sorbate (1000 and 2000 p.p.m.) and MAP, alone and in combination with each other, showed that potassium sorbate, gas packaging or oxygen absorbents (Ageless FX) could extend the shelf life of pizza crusts and decrease the growth rate of molds, bacteria and yeast. Furthermore, when pizza crusts were packaged in 60% CO$ sb2$ or with an oxygen absorbent, in combination with potassium sorbate (1000-2000 p.p.m.), a shelf life of 42d was possible without compromising the sensory shelf life of the product. (Abstract shortened by UMI.)

Chromated copper arsenate (CCA), type C, was largely used as a wood preservative due to its exceptional fungicidal and insecticidal properties. Although this treatment was prohibited for residential purposes in Canada and in the United-States of America, concerns about CCA-treated wood focus on the possible threat on human health and the contamination of the environment, through the leaching of metals from existing structures. The objectives of this thesis are (1) to assess the effects of metals leached from CCA- and ACQ-treated wood on the survival, the growth and the reproductive success of the earthworm Eisenia fetida (Annelida, Oligochaeta), and (2) to evaluate if annetocin, a neuropeptide linked to reproduction, could be used as a biomarker of ecotoxicological responses of the worm E. fetida when exposed to metals from the CCA treatment. Ecotoxicological tests with E. fetida were carried out according to the protocol ISO-11268-2. (Abstract shortened by UMI.)

Thesis (Ph. D. engineering science)--Washington State University, December 2007. / Includes bibliographical references.