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Sodium phosphite was evaluated for inhibition of growth of spoilage yeasts in laboratory media and in two commercial carbonated beverages. In addition, the effects of pH and atmosphere in combination with sodium phosphite were also examined in laboratory media. Inhibition studies in laboratory media were performed with optimal or near optimal growth conditions for each yeast. Growth was monitored by measuring optical density at 600 nm. A time to significant growth was determined for experiments in laboratory media and was used to evaluate the effect that sodium phosphite and other test variables had on growth. A time to detectable growth was determined for experiments in commercial carbonated beverages and post incubation counts on observations with undetectable growth were used to evaluate the effects of sodium phosphite on yeast growth. Sodium phosphite was most effective in inhibiting growth of Zygosaccharomyces bailii, and less effective against Saccharomyces cerevisiae, and Saccharomyces uvarum respectively. Results from this investigation show the potential use of sodium phosphite as an antimicrobial food preservative has potential. / Master of Science

Wood disks in various states of decay can be inexpensively preserved and prepared for accurate crossdating and precise tree-ring measurement by impregnation with commercial wood glue. The technique does not affect the dimensions or physiological features of samples preserved in this manner. Dead red spruce trees on Mt. Washington, New Hampshire, remain available for dendrochronological examination as long as 29 years after their last year of stem growth.

The ability of yeasts to grow and adapt under extreme environmental conditions including within the presence of weak organic acid preservatives has led to substantial economic losses through manufactured food and beverage spoilage. The food industry has employed the use of various weak organic acids such as sorbic, benzoic and acetic acid as preservatives to help prevent spoilage by yeasts and moulds. The mechanisms by which S. cerevisiae is able to adapt to these weak organic acids have been extensively studied. A lesser studied weak organic acid preservative is citric acid. The aim of this study was to gain further information on the mechanisms of citric acid adaptation and through this identify potential targets for new preservation strategies. Current knowledge indicates the involvement of the HOG pathway in citric acid adaptation. A citric acid sensitivity screen from a previous study also isolated a SR protein kinase Sky1p, involved in polyamine metabolism, which has been connected with other crucial cellular processes including modulation of ion homeostasis and osmotic shock. In this study we have undertaken a systematic screen for genes that confer increased sensitivity to citric acid paying particular attention to those involved in polyamine metabolism and those known to encode proteins which have evidence of interactions with Sky1p. Many of the deletion strains tested exhibited hypersensitivity to citric acid including Δsky1. Protein-protein interaction maps for Sky1p highlighted an interesting secondary interacting protein Nmd5p, an importin crucial for the nuclear localization of Hog1p. This information suggested there may be the possibility of linkage between Sky1p and Hog1p and their roles in citric acid tolerance, perhaps through Nmd5p. This provided an incentive to perform a range of experiments to test this theory. Proteomic and phosphoproteomic analyses were carried out to study protein expression and phosphorylation changes in response to citric acid stress. Comparative proteomic analyses for Δsky1, Δhog1 and BY4741a with and without citric acid identified four instances of analogous protein expression responses in both Δsky1 and Δhog1, suggesting functional overlap upon exposure to citric acid. Epistasis studies of Δhog1Δsky1 suggested that the two protein kinases do not function on the same pathway. However, overexpression analyses did suggest some functional interaction between Hog1p and Sky1p in mediating citric acid resistance since overexpression of Sky1p in Δhog1 resulted in partial rescue of growth. Further supporting evidence for some functional interaction or linkage was provided by Hog1p phosphorylation and localisation studies. Δsky1 exhibited dual phosphorylation of Hog1p in the absence of citric acid stress; implying that loss of SKY1 results in dual phosphorylation of Hog1p by either prompting phosphorylation or perhaps by interfering with dephosphorylation of Hog1p. Localisation studies of Hog1p proved that like osmotic stress, citric acid stress results in nuclear translocation of Hog1p and deletion of SKY1 seemed to interfere with this localisation to some extent. In light of the results attained in this study we believe we have evidence to propose a novel role for Sky1p in mediating resistance to citric acid and that there is also substantial evidence to suggest that Sky1p shares some functional redundancy and perhaps functional linkage with Hog1p in citric acid adaptation.

Call number: LD2668 .T4 1986 M375 / Master of Science / Chemistry

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Orientador: Elias Taylor Durgante Severo / Banca: Valdemir Antonio Rodrigues / Banca: Daniel Dias Rosa / Banca: Wagner Roberto Batista / Banca: Fred Willians Calonego / Resumo: No Brasil a exploração e a utilização da madeira de Hevea brasiliensis Mull Arg., no final do ciclo produtivo de látex de 30 a 35 anos, é praticamente desconhecida. Contudo, um dos problemas mais sérios relacionados à sua utilização diz respeito à alta susceptilibilidade da madeira ao ataque de fungos manchadores e insetos, notadamente na fase entre o corte e o processamento primário. Portanto, a adoção de medidas visando à preservação entre os lenhos juvenil e adulto é altamente necessária, garantindo uma maior durabilidade econômica na utilização desse recurso. No presente trabalho foi avaliado o efeito dos ingredientes ativos a base de Quinolinolato de Cobre - 8 e Carbendazim (T1); 2-4-6 Tribromofenol (T2); Extrato vegetal a base de Tanino (T3); Carbendazim e Prochloraz (T4), contra o ataque do fungo manchador Botryodiplodia theobromae em laboratório seguindo a norma ASTM 4445 (2003) e ingredientes ativos a base de Ciflutrina (T5) e Cipermetrina (T6), na avaliação de infestação do cupim de madeira seca Cryptotermes brevis em madeira de Hevea brasiliensis, seguindo a norma IPT - 1157 (1980) e ASTM 3345 (1990). Os resultados mostraram que os ingredientes ativos testados e avaliados isoladamente em laboratório o T1, T2, T3 e T4, não previnem na totalidade a contaminação do Botryodiplodia theobromae nos Lenhos Juvenil e Adulto da madeira de Hevea brasiliensis ao nível de 5% de significânca, e que a velocidade de penetração do fungo manchador difere nos Lenhos Juvenil e Adulto e entre as Secções Transversal, Radial e Longitudinal da madeira. De posse destes resultados, foi estabelecido um modelo que melhor se ajustou estatísticamente foi o não linear do tipo exponencial (Growth 1). Das interações avaliadas na prevenção ao ataque de cupim de madeira seca Cryptotermes brevis... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: In Brazil the exploration and use of the Hevea brasiliensis Mull Arg. wood at the end of the latex production cycle from 30 to 35 years, is practically unknown. However, one of the most significant problems with its use relates to the highly susceptable wood staining fungi and insects, especially in the phase between the primary processing and cutting. The adoption of measures aimed at preserving the trunks between juvenile and adult is highly necessary, ensuring a greater durability in the economic use of this feature. The present study evaluated the effect of the active ingredients of the base Quinolinolato Copper - 8 and Carbendazim (T1); Tribromofenol 2-4-6 (T2); extract-based vegetable Tannin (T3); Carbendazim and Prochloraz (T4), against the attack of the fungus stainer Botryodiplodia theobromae standard ASTM 4445 (2003) and active ingredients the basis of Cypermethrin (T5) and Cyfluthrin (T6) in the evaluation of infestation of the dry wood termite Cryptotermes brevis wood of Hevea brasiliensis standard IPT-1157 (1980) and ASTM 3345 (1990). The results showed that the active ingredients separately tested and evaluated in the laboratory; T1, T2, T3 and T4, will not prevent the total contamination of Botryodiplodia theobromae Firewood in juvenile and adult wood of Hevea brasiliensis the 5% level of significance. The rate of the Firewood in juvenile and adult wood differ when it comes to the stainer's rate of penetration between the transverse, radial and longitudinal timber of Hevea brasiliensis as a function of time. Armed with these results, the non-linear exponential (Growth 1). Interactions evaluated in preventing the attack of dry wood termite Cryptotermes brevis, the two active ingredients the basis of Cypermethrin and Cyfluthrin demonstrated effective in the evaluation of different juvenile... ... (Complete abstract click electronic access below) / Doutor

Dada a importância do camarão para a economia do Brasil e as exigências cada vez mais acentuadas dos países importadores quanto à qualidade do produto final, bem como sua conservação para garantir a oferta de um produto de qualidade aos consumidores, a indústria pesqueira vem utilizando diversas classes de aditivos alimentares: anti-melanóticos, antioxidantes e anti-microbianos. Desta forma, o presente trabalho objetivou avaliar o efeito dos aditivos alimentares: cloreto de sódio, metabissulfito de sódio, nitrito de sódio e ácido cítrico sobre a vida-de-prateleira do camarão Xyphopenaeus kroyeri resfriado, além de avaliar a ação anti-melanótica destes aditivos por 12 dias pós-captura através de escala de graus de melanose. Os camarões dos tratamentos controle (sem aditivo), com metabissulfito de sódio e com nitrito de sódio mantiveram seus valores de pH constantes até o 12º dia de armazenamento e os valores de pH demonstraram correlações positivas com a contagem de mesófilos (r=0,6633;p=0,0070), e com valores de BNVT (r=0,7173; p=0,0026). Durante o período avaliado, os camarões que apresentaram menor produção de bases nitrogenadas voláteis totais foram os imersos em nitrito de sódio (1%), com valores crescentes de 48,20±25,03 no dia 1; 128,00±25,45 no dia 7; 161,50±19,09 no dia 10 e 230,50±33,23 no dia 12. Os valores de força de cisalhamento não exibiram diferença (p>0,05) entre os tratamentos e entre os dias de armazenamento. As bactérias mesófilas e psicotróficas apresentaram as menores contagens nos camarões imersos em cloreto de sódio a 2% e nitrito de sódio a 1%. Não houve crescimento de coliformes termotolerantes, estando todos os tratamentos de acordo com a legislação vigente. O tratamento com metabissulfito de sódio foi o que apresentou menores graus de melanose. Na análise sensorial, não foram encontradas diferenças significativas entre os tratamentos, demonstrando que o uso de aditivos pode auxiliar na preservação da qualidade do camarão sem alterar as características sensoriais do mesmo. / Given the importance of shrimp to the economy of Brazil and progressively greater demands of importing countries as to the quality of the final product as well as its conservation to ensure the provision of a quality product to consumers, the fishing industry has been using various classes’ food additives: non-melanotics, antioxidants and antimicrobials. Thus, this study aimed to evaluate the effect of food additives: sodium chloride, sodium metabisulfite, sodium nitrite and citric acid on the shelf- life of shrimp Xyphopenaeus kroyeri cold, and to evaluate the anti-melanosis action of these additives by 12 days post-capture through melanosis scale degrees. The shrimps of the control treatment (no additive), with sodium metabisulfite and sodium nitrite maintained their pH constant until the 12th day of storage, add the pH values showed positive correlations with counts of mesophilic (r2= 0.6633, p = 0.0070) and with BNVT values (r2= 0.7173, p = 0.0026). During the study period, the shrimp that showed low production of volatile nitrogenous bases were immersed in sodium nitrite (1 %) , with increasing values of 48.20 ± 25.03 on day 1; 128.00 ± 25.45 on day 7; 161.50 ± 19.09 on day 10 and 230.50 ± 33.23 on day 12. Values of shear force showed no difference (p > 0.05) between treatments and between days of storage. The mesophilic and psicotrophic showed the lowest counts shrimps immersed in sodium chloride 2% and sodium nitrite 1%. There was no presence of coliforms growth, with all treatments in accordance with current legislation. Treatment with sodium metabisulfite showed the lowest degree of melanosis. In sensory analysis, no significant differences between treatments were found, demonstrating that the use of additives can assist in preserving the quality of the shrimp without altering the sensory characteristics.

Thesis (M.S.) -- Mississippi State University. Department of Forest Products. / Title from title screen. Includes bibliographical references.

Western juniper and cinnamon essential oils were combined with ethanol at 2.5, 5, and 10% concentrations by weight and applied to hybrid poplar (Populus trichocarpa x P. deltoids) veneers by vacuum soaking to produce a naturally durable wood veneer with increased mechanical properties for use in structural composites. Half of these veneers were then modified using viscoelastic thermal compression to increase veneer density and modulus of elasticity. Following densification, unprocessed and VTC processed veneers receiving an essential oil treatment were subjected to an AWPA E21-06 Formosan termite exposure test, AWPA E24-06 mold box test, and brown rot (Gloeophyllum trabeum) decay bending test. While VTC processing drastically reduced the abundance of chemical components inherent within essential oil treatments, veneer specimens without VTC processing showed increased durability. A 10% juniper oil treatment drastically reduced Formosan termite attack on hybrid poplar veneers while a 10% cinnamon oil treatment significantly reduced mold growth. Timbor��, an industrial powdered borate treatment, withstood VTC processing and inhibited Formosan termite attack and mold growth. Tests to evaluate the effectiveness of essential oil treatments against brown rot were unsuccessful. Results suggest that incorporating a disodium octaborate tetrahydrate (DOT) treatment prior to VTC processing could help improve VTC wood durability. / Graduation date: 2013