The aim of this diploma thesis is the identification of yeasts isolated during grape must fermentation. The must was obtained from Pinot Noir varieties grown in an integrated and organic production. The partner of this thesis was a winery Holánek. In the theoretical part of the work was the emphasis on information about the determinants quality of wine, yeasts and PCR-RFLP method. Physiological properties of yeasts were described and also the principles of the polymerase chain reaction (PCR) were explained. In the experimental part of the thesis was applied molecular biology method PCR-RFLP for identification of yeasts. The specific segment of DNA was amplified (5, 8S-ITS rDNA sequencing) with the help of ITS1 and ITS4 primers. The incurred amplicons were digested by applying restriction endonucleases: HaeIII, HinfI and TaqI. Subsequently the restriction fragments were analysed by using of electrophoresis. The yeasts were identified and classified by taxonomy on the level of genera and species.

This thesis deals with identification of yeasts by applying the RFLP-PCR method. Objective of the thesis was to identify the yeasts present in wine from Grüner Veltliner during fermentation. Identification was made by amplification of 5,8S-ITS sequences of DNA by the polymerase chain reaction with primers ITS1 and ITS4. Amplified DNA was submitted to the restriction analysis by restriction endonuclease HaeIII, HinfI and HhaI. By restriction analysis with a specific enzyme, the amplified DNA is chopped into the specific fragments which are characteristic for given kind of yeasts. In the analysed wine, the dominance of autochthonal yeast Saccharomyces cerevisiae was confirmed throughout fermentation. The other identified yeasts in the wine were of kind Pichia. The second part of the thesis was to expand the database by characterization of 28 type-yeasts, using RFLP-PCR analysis. To compare the genetic similarity, program BioNumerics was used, which processed the results of UPGMA cluster analysis using Jaccard´s coefficients.

The aim of this thesis is the isolation and identification of yeasts obtained from the wine berries and the characterization of the collection yeast by using processes of PCR - RFLP. The type yeasts were obtained from the collection of yeasts of CCY in Bratislava, yeasts from the wine berries were collected from the species of Hibernal wine from the wineries of Štěpán Maňák. Identification of individual yeast is then based on analysis of the DNA segment in the area of 5,8S - ITS using primers ITS1 and ITS4. The restriction analysis was performed using restriction endonucleases HaeIII, HinfI, HhaI a TaqI(a). Restriction analysis is used to chopp the DNA to specific sections that are characteristic for each microorganism. For the assesment of the genetic similarity analyzed yeasts the BioNumerics software has been used. BioNumerics processes the results using cluster analysis using Jaccard´s coefficients.

Orientador: Eleni Gomes / Resumo: O conhecimento das propriedades inerentes aos microrganismos assimiladores de pentoses deve ser obtido para que se desenvolva novas possibilidades de aplicação da biomassa lignocelulósica. A hemicelulose (polissacarídeo rico em pentoses) corresponde em média 25 % da massa da biomassa vegetal e sua hidrólise gera uma mistura de xilose e arabinose. Muitas leveduras, que utilizam pentoses como fonte de carbono, poderiam ser utilizadas direta ou indiretamente (através da expressão heteróloga de seus genes) na bioconversão dessas pentoses em combustível ou em outros produtos de elevado valor mercadológico. Portanto, o objetivo desse trabalho foi avaliar o potencial das cepas Sporidiobolus pararoseus U3, Pichia terricola G20 e Metschnikowia koreensis G18 de crescerem em xilose e arabinose nos pHs 4,5, 6,5 e 8,5, nas temperaturas 29 e 32 °C, na presença de compostos potencialmente tóxicos (8 compostos em três concentrações cada) e em hidrolisados de bagaço de cana. Dados sobre o efeito do pH, nutrientes e oxigenação e fontes de nitrogênio (nitrato de amônio, sulfato de amônio e ureia) em diferentes concentrações no crescimento e produção de ácidos orgânicos foram obtidos para da cepa M. koreensis G18. Todas as leveduras foram capazes de crescer em todos os pHs testados, com destaque as cepas M. koreensis G18 e P. terricola G20, uma vez que a primeira cresceu consideravelmente tanto em 29 °C como em 32 °C e a segunda por crescer mais rápido com arabinose, embora somente a 32 °C. A me... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The knowledge of the properties inherent to the pentoses assimilating microorganisms must be obtained in order to develop new possibilities for the application of lignocellulosic biomass. The hemicellulose (polysaccharide rich in pentoses) corresponds in average 25 % of the mass of the vegetal biomass and its hydrolysis generates a mixture of xylose and arabinose. Many yeasts, which use pentoses as a carbon source, could be used directly or indirectly (through the heterologous expression of their genes) in the bioconversion of these pentoses to fuel or other products of high market value. Therefore, the aim of this work was to evaluate the growth potential of strains Sporidiobolus pararoseus U3, Pichia terricola G20 and Metschnikowia koreensis G18 to grow in xylose and arabinose at pHs 4.5, 6.5 and 8.5 at temperatures of 29 and 32 °C in the presence of potentially toxic compounds (8 compounds in three concentrations each) and sugar cane bagasse hydrolysates. Data on the effect of pH, nutrients and oxygenation and sources of inorganic nitrogen (ammonium nitrate, ammonium sulfate and urea) at different concentrations in the growth and production of organic acids were obtained for the strain M. koreensis G18. All yeasts were able to grow in all tested pHs, with emphasis on the M. koreensis G18 and P. terricola G20 strains, since the former grow considerably both at 29 °C and at 32 °C and the second grow at a faster rate with arabinose, although only at 32 °C. The best pentose an... (Complete abstract click electronic access below) / Doutor

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<p dir="ltr">Romaine lettuce is a vegetable crop that is frequently contaminated with and often implicated in mass outbreaks of human-pathogenic <i>Escherichia coli</i>. To date, research has focused on the specific pathogens responsible for those outbreaks and consumer- and retail-level interventions to eliminate those pathogens or to mitigate their spread. However, in many cases, no singular food source can be identified. Food microbiomes, particularly those associated phylloplanes, are a growing interest area and may be key in identifying the conditions that allow for proliferation of pathogenic organisms like <i>E. coli</i> O157:H7. Further, examination of dominant components of the lettuce microbiome may reveal suitable candidates that can be encouraged or engineered to outcompete or indicate the presence of pathogens. Until recently, most microbiome studies focused on bacteria; less understood are the fungi of these microbiomes. Many fungi have myriad applications in the prevention and mitigation of both human and plant diseases. Thus, to effectively prevent pathogenic <i>E. coli </i>outbreaks, a fundamental understanding about the fungi that cohabit the lettuce microbiome is paramount. The most frequently isolated yeast in the romaine lettuce microbiome is an undescribed yeast, revealing the dearth of information regarding nonpathogenic fungi in food systems. First, the novel yeast <i>Sporobolomyces lactucae</i> is described using a multi-locus phylogeny through genealogical gene concordance, with a discussion on the potential ecological range. Second, the genome of <i>S. lactucae </i>strain HU9244 is assembled and annotated with transcriptomic information to help guide target gene selection for biotechnology, particularly in identifying candidates for reporter genes that may assist in the detection of <i>E. coli </i>O157:H7 via olfactory or visual cues. Third, the distribution of the yeast <i>S. lactucae</i> is determined, finding the organism in various climate types and potentially on other leafy greens as well, indicating its suitability for <i>in situ</i> detection of foodborne pathogens such as <i>E. coli</i> O157:H7 commonly found on romaine lettuce and other leafy greens.</p>

Thesis (PhDAgric (Viticulture and Oenology. Wine Biotechnology))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: Stuck alcoholic fermentations are a major enological problem for the international winemaking industry. Incomplete wine fermentations are frequently characterized by high residual fructose concentrations and the near-absence of residual glucose, a fact that is due to the glucophilic character of the wine yeast Saccharomyces cerevisiae. Wines with high contents of post fermentation sugar are very susceptible for microbial spoilage since residual fructose and/or glucose can be metabolized by bacteria and yeast to undesired by-products such as volatile acid and off-flavours, resulting in wine spoilage and considerable economic losses. It has been reported that stuck fermentations are usually caused by several synergistically acting inhibition factors, and the glucose to fructose ratio (GFR) is thought to play an important role in this context. This study is aimed at contributing towards a better understanding of this industrial problem, and at finding industrially applicable solutions. In a first part, this study describes the isolation of two appropriate strains of the fructophilic yeast Zygosaccharomyces bailii from the natural microflora of grapevine, followed by trials in small scale test fermentations using stuck industrial fermentations as model media. These experiments were expanded to also investigate large scale industrial fermentations. As a result, a strategy for the treatment of stuck fermentations was developed and successfully applied in several wineries with fermentation problems. This methodology represents an entirely novel and industrially applicable solution to high residual fructose levels. In a second part, the data contributes to elucidating the molecular nature of the fructophilic phenotype of Z. bailii by characterizing some of the genes and proteins that may be responsible for the fructophilic character. In particular, the investigation focused on the first two steps of hexose metabolism, the transport of sugar into the cell by permeases and sugar phosphorylation by hexokinases, which combined are thought to be primarily responsible for sugar preference. One result of this study was Fructoferm W3©, a dry yeast product which is commercially available. Fructoferm W3 was awarded with the innovation medal for enological products at Intervitis/Interfructa, Stuttgart, Germany in 2007. / AFRIKAANSE OPSOMMING: Die voorkoms van steek alkoholiese fermentasies is ‘n ernstige problem in die internasionale wyn industrie. Onvolledige fermentasies word dikwels gekenmerk deur hoë residuele fruktose konsentrasies en die veitlike afwesigheid van residuele glukose. Die kenmerke kan meestal toegeskryf word aan die glukofilliese kakakter van die wyngis Saccharomyces cerevisiae. Wyne met ‘n hoë suiker inhoud na die afloop van fermentasie is vatbaar vir mikrobiese bederf aangesien residuele fruktose en/of glukose gemetaboliseer kan word deur bakterië en gis om ongewenste byprodukte soos vlugtige sure en bygeure te vorm wat kan lei tot wyn bederf en aansienlike ekonomies verlies. Dit is vasgestel dat steek fermentasies gewoonlik veroorsaak word deur verskeie sinergisties werkende inhibisie faktore, waartoe die glukose/fruktose verhouding ‘n noemenswaardiege bydrae lewer. Die mikpunt van hierdie studie was om ‘n bydrae te lewer tot die begrip van steek fermentasies en die daarstelling van moontlike industriële oplossings. Die eerste deel van die werk beskryf die isolasie van twee rasse van die gis Zygosaccharomyces baillie uit die natuurlike wingerd mikroflora, gevolg deur steekproewe in die vorm van kelinskaalse fermentasies met steek industriële fermentasies gebruik as model media. Hierdie ekserimente is vervolgens uitgebrei om grootskaalse industriële steek fermentasies te bestudeer. Die uitkoms van hierdie werk het gelei tot die ontwikkeling van ‘n strategie vir die behandeling van steek fermentasies wat susksesvol toegepas is in verskeie wynmakerye. Die metodiek bring ‘n nuwe en industrieel toepasbare oplossing vir hoë residuele fruktose vlakke. Die data aangebied in die tweede afdeling dra by tot die verheldering van die molekulêre natuur van die fruktofilliese fenotipe van Z. baillie deur die tipering van gene en protiëne wat moontlik verantwoordelik is vir die fruktofilliese karakter van die gis. Die ondersoek het spesifiek op die eerste twee stappe van heksose metabolisme, naamlik die invoer van suiker in die sel deur permeases en suiker fosforilering deur heksokinases, gekonsentreer. Die kombinasie van die twee prosesse is vermoedelik verantwoordelik vir die regulering van suiker voorkeur. ‘n Gevolg van die studie was die ontwikkeling van ‘n droë gisproduk, Fructferm W3©, wat kommersieel beskikbaar gestel is. Fructoferm W3 is in 2007 toegeken met die innovasie medalje vir wynkundige produkte by Intervittis/Interfructa in Stuttgart, Duitsland.

O selênio é um não metal da família 6A e um micronutriente essencial para a saúde animal e humana, com importante ação antioxidante, atuando na prevenção de diversas doenças. O consumo de biomassa de levedura enriquecida com selênio aumenta sua absorção pelo organismo e reduz o risco dos efeitos tóxicos causados pelo consumo de sua forma inorgânica, selenito de sódio. A produção de leveduras enriquecidas com selênio a partir de resíduos amiláceos e lignocelulósicos como fontes de carbono e de nitrogênio é uma alternativa de baixo custo e inovadora. Neste contexto, o presente trabalho teve como objetivo a produção de biomassa de levedura enriquecida com selênio para alimentação animal a partir de resíduos da agroindústria. Foram avaliadas sete linhagens, pertencentes às espécies Candida utilis, Kluyveromyces marxianus, Rhodotorula glutinis e Saccharomyces cerevisiae. Realizaram-se estudos em cultivo submerso com selenito de sódio para avaliar os efeitos no metabolismo microbiano, com ênfase no crescimento celular e incorporação de selênio. Todas as linhagens avaliadas foram capazes de crescer e incorporar selênio, sendo que S. cerevisiae SSS41 apresentou elevada tolerância a esse composto e capacidade de crescimento em hidrolisados amiláceos, acrescidos de selênio. Entre os hidrolisados utilizados no processo fermentativo, o hidrolisado de farelo de soja apresentou elevada concentração de proteínas, não sendo necessária sua suplementação com nutrientes para que a linhagem S. cerevisiae SSS41 produzisse 7,0 g/L de biomassa celular e incorporasse 2375 ppm de selênio. Com a adição de nutrientes e de concentrações mais elevadas de selênio o crescimento celular se manteve constante, porém a incorporação de selênio foi superior a 11000 ppm. Em cultivos realizados com melaço de cana-de-açúcar o crescimento celular foi de 4,17 ± 0,24 g/L, com incorporação de 6528 ± 10 ppm de selênio. Além dos cultivos submersos, também foi realizada fermentação em estado sólido com a levedura R. glutinis CCT-2186, utilizando bagaço de cana-de-açúcar e farelo de arroz hidrolisado como substratos sólidos e hidrolisado de farelo de arroz com e sem a adição de selênio na solução umedecedora. Nos ensaios realizados, a levedura foi capaz de crescer e incorporar 6038 ± 1219 ppm de selênio. O consumo de biomassa de levedura enriquecida com selênio apresenta diversos benefícios à saúde e a utilização de resíduos agroindustriais vegetal é um processo inovador e reduz os custos de produção. / Selenium is an essential micronutrient for animal and human health, with na important antioxidant role, preventing several diseases. Consumption of Se-enriched yeast biomass increases selenium absorption in the digestion process and it is less toxic than its inorganic salt, sodium selenite. The production of Se-enriched yeasts from lignocellulosic and starchy residues as carbon and nitrogen sources is na inexpensive and novel alternative. In this context, the present study aims to produce Se-enriched yeast biomass for animal feed from agroindustrial wastes. Seven yeast strains were evaluated from species Candida utilis, Kluyveromyces marxianus, Rhodotorula glutinis and Saccharomyces cerevisiae. Studies were carried out in submerged culture containing sodium selenite, to verify the effects on microbial metabolism, with emphasis on cell growth and selenium incorporation. All strains evaluated were able to grow and incorporate selenium and S. cerevisiae SSS41 presented high tolerance to this compound and growth capacity in starch hydrolysates containing selenium. Among the hydrolysates used in the fermentation process, soybean bran presented a high protein concentration, and no nutriente supplementation was necessary for the production of 7.0 g/L cellular biomass and incorporation of 2375 ppm of selenium by S. cerevisiae SSS41 strain. With the addition of nutrients and higher concentrations of selenium, cell growth remained steady, but the incorporation of selenium was higher than 11000 ppm. In fermentations carried out with sugarcane molasses, the cell growth of S. cerevisiae SSS41 was 4.17 ± 0.24 g/L, incorporating 6528 ± 10 ppm of selenium. In parallel, solid-state fermentation was carried out with yeast R. glutinis CCT-2186, using sugarcane bagasse and hydrolyzed rice bran as solid substrates and rice bran hydrolyzate with and without the addition of selenium in humidifying solution. In these conditions, the yeast was able to grow and incorporate 6038 ± 1219 ppm of selenium. The consumption of selenium-enriched yeast biomass has several health benefits and the use of agro-industrial wastes is an innovative process and reduces production costs.

Hidrolisados hemicelulósicos como o resultante do processamento do bagaço de cana-de-açúcar para obtenção do etanol celulósico, constituem uma fonte rica em açúcares, em particular xilose. Considerando o potencial destes hidrolisados para utilização por micro-organismos fermentadores de pentoses e a disponibilidade de leveduras xilanolíticas isoladas da Antártica, a presente pesquisa tem como objetivo avaliar o cultivo destas leveduras no hidrolisado hemicelulósico de bagaço de cana-de-açúcar com vistas à obtenção de bioprodutos. Os experimentos foram realizados empregando-se 16 leveduras xilanolíticas isoladas de diferentes fontes. Inicialmente estas foram repicadas em ágar Sabouraud e cultivadas em diferentes temperaturas, selecionando-se para o cultivo em hidrolisado hemicelulósico aquelas que cresceram neste meio. Os cultivos no hidrolisado foram realizados em triplicata em frascos Erlenmeyer, a 200 rpm, a 30°C em duas etapas: O primeiro ocorreu por 72 h e as leveduras que cresceram neste período foram as empregadas para avaliação do cultivo no hidrolisado e também em meio semi-definido simulando a composição em açúcares deste hidrolisado por um período de 96h. Neste caso as avaliações ocorreram a cada 24h a partir da determinação da concentração de açúcares, formação de células, xilitol e etanol, pH, concentração dos tóxicos ácido acético, hidroximetilfurfural, furfural e fenólicos. O experimento controle foi empregado utilizando-se Candida guillermondii já bastante pesquisada nas fermentações que empregam hidrolisado hemicelulósico de bagaço de cana. Foi verificado que 6 das leveduras testadas foram capazes de assimilar os açúcares presentes no hidrolisado, sendo que apenas a Cryptococcus adeliensis (L95) apresentou capacidade de produzir etanol como produto deste metabolismo, enquanto as leveduras Cryptococcus aff laurentii (L62), Candida davisiana (L101 e L107) e Cryptococcus adeliensis (L108) apresentaram indícios de atividade xilanolítica. Com relação aos compostos tóxicos presentes no hidrolisado verificou-se que em alguns cultivos ocorreu decréscimo na concentração destes e a manutenção da viabiliadade celular ao final do cultivo. Considerando o caráter inovador da presente pesquisa faz-se necessário a continuidade da investigação a fim de se estabelecer as melhores condições de cultivo destas leveduras para fins de aproveitamento biotecnológico de hidrolisados hemicelulosicos, em função do desempenho destas em relação à C. guilliermondii. / Hemicellulose hydrolysates, as the result of sugarcane bagasse processing for obtaining cellulosic ethanol, are a rich source of sugars, especially xylose. Considering the potential of these hydrolysates for the use by pentoses fermenting micro-organisms and the availability of xylanolytic yeasts isolated from Antarctica, this research aims to evaluate the cultivation of these yeasts in hemicellulose hydrolysate of sugarcane bagasse in order to obtain bioproducts. The experiments were performed by employing 16 xylanolytic yeasts isolated from different sources. Initially, they were transferred in Sabouraud agar and grown at different temperatures, and those that grew in this medium were selected for cultivation in hemicellulose hydrolysate. The cultures in the hydrolysate were performed in triplicate in Erlenmeyer flasks at 200 rpm at 30 ° C in two stages: The first one occurred for 72 h and the yeasts that grew in this period were used for the evaluation of growth in the hydrolysate and also in semi-defined medium simulating the sugar composition of this hydrolysate for 96h. In this case, the evaluations occurred every 24 hours from the determination of sugars concentration, formation of cell, xylitol and ethanol, pH, concentration of the toxics acetic acid, hydroxymethylfurfural, furfural and phenols. A control experiment was employed using Candida guillermondii which has been well investigated in fermentations employing sugarcane bagasse hemicellulose hydrolysate. It was verified that 6 of the tested yeasts were able to assimilate the sugars present in the hydrolysate, and only Cryptococcus adeliensis (L95) showed ability to produce ethanol as a product of this metabolism, while the yeasts Cryptococcus aff laurentii (L62), Candida davisiana (L101 and L107) and Cryptococcus adeliensis (L108) showed evidences of xylanolytic activity. With respect to toxic compounds present in hydrolysate, it was verified that, in some cultures, the decrease in their concentration and the maintenance of cell viability at the end of cultivation occurred. Due to the innovative nature of this research, it is necessary to continue the investigation in order to establish the best conditions for this yeasts cultivation with the purpose of biotechnological exploitation of hemicellulose hydrolysates, depending on their performance regarding C. guilliermondii.

Hidrolisados hemicelulósicos como o resultante do processamento do bagaço de cana-de-açúcar para obtenção do etanol celulósico, constituem uma fonte rica em açúcares, em particular xilose. Considerando o potencial destes hidrolisados para utilização por micro-organismos fermentadores de pentoses e a disponibilidade de leveduras xilanolíticas isoladas da Antártica, a presente pesquisa tem como objetivo avaliar o cultivo destas leveduras no hidrolisado hemicelulósico de bagaço de cana-de-açúcar com vistas à obtenção de bioprodutos. Os experimentos foram realizados empregando-se 16 leveduras xilanolíticas isoladas de diferentes fontes. Inicialmente estas foram repicadas em ágar Sabouraud e cultivadas em diferentes temperaturas, selecionando-se para o cultivo em hidrolisado hemicelulósico aquelas que cresceram neste meio. Os cultivos no hidrolisado foram realizados em triplicata em frascos Erlenmeyer, a 200 rpm, a 30°C em duas etapas: O primeiro ocorreu por 72 h e as leveduras que cresceram neste período foram as empregadas para avaliação do cultivo no hidrolisado e também em meio semi-definido simulando a composição em açúcares deste hidrolisado por um período de 96h. Neste caso as avaliações ocorreram a cada 24h a partir da determinação da concentração de açúcares, formação de células, xilitol e etanol, pH, concentração dos tóxicos ácido acético, hidroximetilfurfural, furfural e fenólicos. O experimento controle foi empregado utilizando-se Candida guillermondii já bastante pesquisada nas fermentações que empregam hidrolisado hemicelulósico de bagaço de cana. Foi verificado que 6 das leveduras testadas foram capazes de assimilar os açúcares presentes no hidrolisado, sendo que apenas a Cryptococcus adeliensis (L95) apresentou capacidade de produzir etanol como produto deste metabolismo, enquanto as leveduras Cryptococcus aff laurentii (L62), Candida davisiana (L101 e L107) e Cryptococcus adeliensis (L108) apresentaram indícios de atividade xilanolítica. Com relação aos compostos tóxicos presentes no hidrolisado verificou-se que em alguns cultivos ocorreu decréscimo na concentração destes e a manutenção da viabiliadade celular ao final do cultivo. Considerando o caráter inovador da presente pesquisa faz-se necessário a continuidade da investigação a fim de se estabelecer as melhores condições de cultivo destas leveduras para fins de aproveitamento biotecnológico de hidrolisados hemicelulosicos, em função do desempenho destas em relação à C. guilliermondii. / Hemicellulose hydrolysates, as the result of sugarcane bagasse processing for obtaining cellulosic ethanol, are a rich source of sugars, especially xylose. Considering the potential of these hydrolysates for the use by pentoses fermenting micro-organisms and the availability of xylanolytic yeasts isolated from Antarctica, this research aims to evaluate the cultivation of these yeasts in hemicellulose hydrolysate of sugarcane bagasse in order to obtain bioproducts. The experiments were performed by employing 16 xylanolytic yeasts isolated from different sources. Initially, they were transferred in Sabouraud agar and grown at different temperatures, and those that grew in this medium were selected for cultivation in hemicellulose hydrolysate. The cultures in the hydrolysate were performed in triplicate in Erlenmeyer flasks at 200 rpm at 30 ° C in two stages: The first one occurred for 72 h and the yeasts that grew in this period were used for the evaluation of growth in the hydrolysate and also in semi-defined medium simulating the sugar composition of this hydrolysate for 96h. In this case, the evaluations occurred every 24 hours from the determination of sugars concentration, formation of cell, xylitol and ethanol, pH, concentration of the toxics acetic acid, hydroxymethylfurfural, furfural and phenols. A control experiment was employed using Candida guillermondii which has been well investigated in fermentations employing sugarcane bagasse hemicellulose hydrolysate. It was verified that 6 of the tested yeasts were able to assimilate the sugars present in the hydrolysate, and only Cryptococcus adeliensis (L95) showed ability to produce ethanol as a product of this metabolism, while the yeasts Cryptococcus aff laurentii (L62), Candida davisiana (L101 and L107) and Cryptococcus adeliensis (L108) showed evidences of xylanolytic activity. With respect to toxic compounds present in hydrolysate, it was verified that, in some cultures, the decrease in their concentration and the maintenance of cell viability at the end of cultivation occurred. Due to the innovative nature of this research, it is necessary to continue the investigation in order to establish the best conditions for this yeasts cultivation with the purpose of biotechnological exploitation of hemicellulose hydrolysates, depending on their performance regarding C. guilliermondii.