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Orientador: Fernando Carlos Pagnocca / Banca: Allen Norton Hagler / Banca: Carlos Augusto Rosa. / Banca: Mauricio Bacci Junior / Banca: Jonas Contiero. / No período de março de 1999 a fevereiro de 2002, foram coletadas 311 flores e 72 frutos de 19 espécies vegetais nativas de Mata Atlântica na região de Ubatuba, SP - núcleo Picinguaba, com o objetivo de descrever as espécies de leveduras presentes. Os locais de coleta abrangeram uma grande extensão de áreas de mata de encosta, planície, restinga e beira mar. Ainda, 75 amostras da água acumulada nos tanques de outras duas espécies vegetais foram analisadas com o mesmo objetivo. Trezentas e vinte e seis linhagens de leveduras foram isoladas, das quais, 75,8% apresentaram afinidade ascomicética e 24,2% basideomicética. O gênero Candida foi predominante, seguido por Metschnikowia, Hanseniaspora, Bullera e Cryptococcus. Entre os ascomicetos e seus anamorfos, 37 espécies foram identificadas, sendo que a espécie mais freqüentemente isolada em flores e frutos foi Hanseniaspora uvarum, com 22 e 20 isolados, respectivamente. Outras espécies que também foram isoladas com freqüência em flores foram Bullera unica e Metschnikowia koreensis. Como esperado, muitas das linhagens isoladas não se enquadraram dentro dos padrões descritos na literatura e, nesses casos, as mais freqüentes tiveram a região do domínio D1/D2 do rDNA seqüenciada. Todos os oito isolados da nova espécie Candida leandrae foram obtidos a partir de frutos de Leandra reversa (Melastomataceae), sugerindo forte associação entre ambos. Das amostras da água de tanque foram isoladas cinco novas espécies. De Canistropsis seidelii (Bromeliaceae) foram descritas duas novas espécies: Candida bromeliacearum e Candida ubatubensis. A partir de Heliconia velloziana (Heliconiaceae) foram descritas Candida heliconeae, Candida picinguabensis e Candida sanpauloensis. Alguns isolados designados como Candida sp. A, B, C, D, E, F, G, H, I e Debaryomyces sp. A, B, C e outros, também não corresponderam às características das espécies-padrão descritas na literatura e ainda não foram seq / From March of 1999 to February of 2002, 311 flowers and 72 fruits of 19 native plant species of the Atlantic Forest in the region of Ubatuba, SP Picinguaba area were sampled for the presence of yeasts. The sites of collection included a great extension of coastal areas like hillsides, plains, restinga and seashores. Seventy five samples of the water accumulated in the tank of two other plant species were also examined. Three hundred and twenty six yeast strains were isolated, with 75.8% being ascomycetes and 24.2% basideomycetes. The genus Candida was predominant, followed by Metschnikowia, Hanseniaspora, Bullera and Cryptococcus. Regarding the ascomycetous and their anamorphs, 37 species were identified, and Hanseniaspora uvarum was the prevalent in flowers and fruits, with 22 and 20 isolated respectively. Bullera unica and Metschnikowia koreensis were also frequently isolated from flowers. As expected, many of the strains did not fit the standard found in literature and most of them had their D1/D2 domain of rDNA sequenced. All the eight strains of new species, Candida leandrae were isolated from fruits of Leandra reversa (Melastomataceae), suggesting a strong association between them. Another five new species were isolated from tank water as follows: Candida ubatubensis and Candida bromeliacearum from Canistropsis seidelii (Bromeliaceae) and Candida heliconeae, Candida sanpauloensis and Candida picinguabensis from Heliconia velloziana (Heliconiaceae). Some strains previously identified as Candida sp. A, B, C, D, E, F, G, H, I and Debaryomyces sp. A, B, C and others, could not be identified as well but they were not sequenced to date / Doutor

Made available in DSpace on 2014-10-09T12:22:56Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:56:33Z (GMT). No. of bitstreams: 1 00791.pdf: 1221250 bytes, checksum: adda6bad55b7b9d008e7d6de5a1e589f (MD5) / Dissertacao (Mestrado) / IEA/D / Escola Politecnica, Universidade de Sao Paulo - POLI/USP

The objective of the experiments was to compare qualitatively the monosaccharides in the hydrolysis products of the extracellular polysaccharides of several yeasts and yeast-like fungi. Specifically, the study was aimed at finding similarities and differences that might be useful in suggesting and supporting taxonomic relationships. Gas chromatography and paper chromatography were used as methods of analyses in an effort to find out what method is sufficient at the qualitative level for distinguishing some genera of yeasts and yeast-like fungi; and what method would be best at the quantitative level for distinguishing amongst some species of the same genus. From the analytical results it was found that paper chromatography using the solvents ethyl acetate: pyridine: water, (8:2:2) was sufficient for qualitative determination of the monosaccharides in the extracellular polysaccharide hydrolysis products. However, indications were that quantitative analyses by gas chromatography, using the trimethylsilyl derivatives of the monosaccharides would have been successful in distinguishing among species of the same genus. Two groups were formed on the bases of the qualitative results. Group I contained two subgroups. Subgroup I encompassed those yeasts and yeast-like fungi with the monosaccharides galactose, glucose, mannose, xylose present in the hydrolysis products of their extracellular polysaccharides. Included in this Subgroup I are: Cryptococcus laurentii, Tremella mesenterica, Bullera alba, Sporobolomyces odorus, Sporobolomyces singularis, and Rhodotorula glutinis. Subgroup II is Ustilago hordei only, with the monosaccharides galactose, glucose, mannose, and lacking xylose. Group II contains Taphrina populina only, with glucose and mannose present and both galactose and xylose absent. The two groups formed support some of the taxonomic relationships that have already been suggested. The Tremella - Cryptococcus taxonomic relationship that had previously been postulated on the basis of similarities in extracellular polysaccharide hydrolysis products, morphology, carbon assimilation patterns, enzymatic xylosylation reaction, and starch formation was supported. Secondly, the Cryptococcus-Bullera relationship that had been suggested on the basis of inositol assimilation, lack of pseudomycelium, and similarities in starch synthesis, was supported by the qualitative analysis of the monosaccharides present in the extracellular polysaccharide hydrolysis products. The monosaccharides found in both Cryptococcus laurentii and Bullera alba extracellular polysaccharides were the same qualitatively. Duality amongst species of Sporobolomyces might be supported with further work using quantitative gas chromatographic analyses. This duality had been postulated on account of the duality shown in antigenic analyses and percent G+C base analyses of DNA. Taphrina populina can be distinguished from Rhodotorula glutinis and Cryptococcus laurentii. Cryptococcus laurentii produces starch and assimilates inositol: Rhodotorula glutinis assimilates inositol but does not produce starch; and Taphrina populina produces starch but does not assimilate inositol. Two monosaccharides present in the extracellular polysaccharide hydrolysis products of both Cryptococcus laurentii and Rhodotorula glutinis are galactose and xylose whereas Taphrina populina lacks these two monosaccharides. Results obtained from the qualitative analyses of the extracellular polysaccharides produced by fungi may be important taxonomically. This is because the qualitative information may be used when deciding on Perfect-Imperfect fungal relationships. However, this information should be considered along with data from other fields such as morphology, cytology, and genetics before hypothesizing on a taxonomic relationship. / Science, Faculty of / Botany, Department of / Graduate

This research project is concerned with the use of an amylolytic yeast, Endomycopsis sp., for simultaneous production of yeast protein and crude amylase preparations from natural starch materials. The Endomycopsis yeasts were cultivated alone and in combination with other yeasts which are unable to attack starch directly. The propagations were carried out in the presence of urea and phosphate, under aerobic conditions, with vigorous agitation, at pH 5.0 and 28°C. At daily intervals, the cultures were analyzed for protein yield, cell density, and amylase activity. The cell crop harvested after propagation of Endomycops is yeasts on 6.0% potato media contained 19% protein and the culture filtrate obtained after biomass separation had an activity of 1.5 units. Variations in activity and protein content were observed, depending on the starch substrate used, the concentration of urea added, and apparently, the amount of oxygen supplied. Mixed preparations using Candida utilis as ancillary yeast, gave higher protein yields and amylase activities compared to single propagations of Endomycopsis sp. and mixed propagations with Saccharomyces cerevisiae. Purple yam and cassava tubers were examined for protein enrichment and amylase production. It was observed that the protein content of the cell crops obtained from these substrates could be increased about ten-fold but that the amylase activities of the culture filtrates were very low . / Land and Food Systems, Faculty of / Graduate

Orientador: Marco Aurelio Cremasco / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-15T13:21:38Z (GMT). No. of bitstreams: 1 Melo_KikiPinheiro_D.pdf: 15983224 bytes, checksum: 1c988a8b59f7838580bd3500b217ba4a (MD5) Previous issue date: 2010 / Resumo: Nesta Tese de doutorado foi feita a avaliação de um secador atmosférico condutivo com agitação mecânica, utilizando-se esferas de vidro como material inerte, na secagem do sedimento resultante da centrifugação do resíduo da indústria de cerveja, levedura da espécie Saccharomyces cerevisiae, após ser reutilizada na fabricação de cerveja por oito vezes. O secador operou com carga de sedimento de levedura (150 g e 300g), temperatura da superfície de aquecimento (60°C e 90°C) e velocidade de rotação do impelidor (15 rpm e 30 rpm). A levedura na forma original (suspensão) comporta-se reologicamente como um fluido newtoniano para temperaturas até 45ºC, não-newtoniano para temperaturas entre 45ºC e 75ºC (plástico de Bingham). O sobrenadante comporta-se como fluido newtoniano nas temperaturas de 25°C a 40°C, entre 45ºC e 75ºC apresenta comportamento dilatante e o sedimento como um fluido não-newtoniano (pseudoplástico). Avaliando a remoção de voláteis ao longo do tempo, foi possível identificar mecanismos e etapas distintas de secagem para o sedimento de levedura como consequência dos parâmetros operacionais do secador. Além disso, observou-se também que tais parâmetros afetam o produto seco, ou seja, influenciam na distribuição granulométrica, no diâmetro médio de partícula e área específica do mesmo, com menor intensidade a massa específica dos aglomerados, e de modo irregular a esfericidade das partículas. A maior rotação do impelidor conduz a menores valores para os diâmetros médios de aglomerados e efeito contrário é observado com o aumento da carga de sedimento, pois apresenta maior volume de material. Em ensaios preliminares, foi identificado um grande potencial de utilização do subproduto das dornas de fermentação da indústria cervejeira na forma de pó, a levedura S. cerevisiae, como bioadsorvente para o tratamento de soluções aquosas de metais, principalmente de chumbo (II) com cerca de 90% de remoção. A qualidade do produto em forma de pó também foi avaliada na aplicação como complemento alimentar e constatou-se que o teor de proteína fica entre 55,22% a 58,35%, assim como apresenta um indicativo como complemento nutricional, principalmente em associação ao milho, devido ao alto teor de lisina encontrado. / Abstract: This thesis allowed evaluating the conductive atmospheric dryer with mechanical agitation, using glass beads as inert particles for drying a residue from brewery (yeast of Saccharomyces cerevisiae species) after being used eight times. The dryer was operated with the sediment load of yeast (150 g and 300 g), heating surface temperature (60 ºC and 90 ºC) and impeller rotational speed (15 rpm and 30 rpm). The yeast suspension behaves rheologically as a Newtonian fluid for temperature up to 45 º C, as a non-Newtonian fluid at temperatures between 45 ºC and 75 ºC (Binghan plastic). The supernatant also behaves as Newtonian fluid for temperature of 25 ºC until 40 ºC, between 45 ºC and 75 ºC shows dilatant behavior and their sediment as non-Newtonian fluid characterized as pseudoplastic. For the removal of volatile over time it was possible to identify mechanisms and distinct stages of yeast sediment drying as a result of dryer operating parameters. In addition, it was also observed that dryer parameters affect the dry product, or influence the average particle diameter and specific area, in lesser extent the clusters density, and in an so irregular way for the particles sphericity. High impeller rotation leads to lower values for average diameter of clusters. The opposite effect is observed with increasing sediment load, because it presents greater material volume. In preliminary tests, it was identified a great potential for use of the by-product of fermentation vessels from beer industry (in powder form), the Saccharomyces cerevisiae yeast as bioadsorbent for the treatment of aqueous solutions of metals, particularly lead (II) with about 90% of removal. The quality of the product in powder form was also evaluated in application as a food supplement. In yeast powder, it was found a protein content between 55.22% and 58.35%. This protein content gives na indication of its use as a nutritional supplement, especially in combination with corn, due to the high lysine content founded. / Doutorado / Engenharia de Processos / Doutor em Engenharia Química

Yeasts, broadly defined as unicellular fungi, have a disproportionate impact on human health and economy despite comprising less than 1% of the fungal kingdom. Soil is a primary yeast habitat where they play essential roles in decomposition, nutrient cycling and as food sources for other soil dwellers. Cryptococcus deneoformans is a basidiomycetous yeast commonly found in soil in association with pigeon droppings. As an opportunistic pathogen of humans, it contributes to 181,000 deaths caused by cryptococcosis and fungal meningitis worldwide every year. Significant intraspecific variation in melanin synthesis, an essential virulence factor of C. deneoformans, is observed in natural populations, with its genetic basis remaining largely unknown. My thesis investigated global patterns in soil yeast diversity where we identified mean annual precipitation and international human travel as two, strong predictors of soil yeast diversity worldwide. We discovered a novel C. deneoformans population in Saudi Arabian desert soils, likely a recent introduction to the region facilitated by anthropogenic activities. Using bulk segregant analysis and gene expression assays, we identified six, novel candidate genes that potentially contribute to intraspecific melanin variance in C. deneoformans. Finally, we investigated genome-wide allele distribution patterns in hybrid strains derived from mating between C. deneoformans and its sister species, C. neoformans. Significantly skewed allele distributions we detected in hybrid genomes highlight the genomic incompatibilities between the two species and support their classification into two, distinct species which has been a topic of much debate. Overall, my PhD thesis makes several contributions to our understanding of soil yeast communities, genetics of virulence factors in C. deneoformans, and outcomes of hybridization between fungal lineages. / Thesis / Candidate in Philosophy / Yeast species have been an integral part of human civilization for centuries, with earliest evidence of yeast-fermented beverages dating back to 7000 B.C. Soil is a primary yeast habitat where yeasts with diverse profiles, including those infectious to humans, reside. Cryptococcus deneoformans is a soil yeast that infects people via the respiratory tract to cause serious systemic infections, resulting in 181,000 deaths worldwide every year. C. deneoformans’s ability to produce melanin pigments is a crucial factor in its success as an infectious agent. My thesis investigated global patterns in soil yeast diversity, with a focus on the genetic factors that regulate melanin synthesis in C. deneoformans. I explored the potential impacts of anthropogenic activities on soil yeast communities, as exemplified by the ongoing hybridization between C. deneoformans and its sister species, which were previously geographically isolated. Findings of my thesis advance our knowledge on yeast biology, infections, and genetics research.

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Made available in DSpace on 2014-06-11T19:31:00Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-07-24Bitstream added on 2014-06-13T20:41:04Z : No. of bitstreams: 1 batistote_m_dr_araiq.pdf: 1258136 bytes, checksum: f9f580d2a88ef74edcdd73a29908a401 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O presente trabalho teve como objetivo principal realizar estudos do efeito da complexidade estrutural de fontes de nitrogênio no fluxo metabólico do carbono em leveduras industriais utilizadas nas indústrias de panificação, de produção de vinhos e cervejas. Os resultados obtidos com os carboidratos trealose e glicogênio estão de acordo com o comportamento esperado para o acúmulo destes compostos, uma vez que foi observado que a quantidade destes carboidratos de reserva nas células sofrem acentuadas variações em resposta a diferentes alterações nutricionais experimentadas pelas leveduras durante o processo fermentativo, e isto ocorre como conseqüência do complexo sistema regulatório que controla a produção dos carboidratos. A maioria dos dados indica que a quantidade de trealose e glicogênio foram sempre maiores na suplementação com amônio e menor com peptona. A concentração de trealose e glicogênio produzidas pelas linhagens talvez reflita o processo de seleção a que foram submetidas as linhagens, o tipo a e concentração da fonte de carbono, o tempo de fermentação e também com a natureza estrutural da fonte de nitrogênio. / The present work had as main objective to carry out studies of effects of the structural complexity of nitrogen sources in the metabolic flux of carbon in industrial yeasts used in the production of bread, wines, and beers. The results obtained with the carbohydrates trehalose and glycogen are in accordance with the expected behavior for the accumulation of these compounds, once it was observed that the amount of these reserve carbohydrates of in the cells suffers accented variations in response to the different nutritional alterations experienced by the yeasts during the fermentative process. This may occurs as consequence of the complex regulatory system that controls the production of the carbohydrates. The majority of the data indicates that the amount of trehalose and glycogen was always higher under ammonium and casamino acids supplementation than with peptone. Perhaps the concentration of trehalose and glycogen produced by the strains reflects the process of selection that the strains were submitted, the type and concentration of the carbon source, the time of fermentation and also with the structural nature of the nitrogen source.