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O objetivo do estudo foi avaliar o processo de hidrólise da sacarose pela ação de enzimas presentes em leveduras de panificação (Saccharomyces cerevisiae) em solução de açúcar VHP e caldo de cana-de-açúcar. Também foi avaliado a produção e caracterização de melado de cana-de-açúcar com inversão parcial da sacarose por adição de leveduras de panificação nas condições selecionadas. Verificou-se que é possível hidrolisar parcialmente a sacarose do caldo de cana-de-açúcar pela ação de enzimas presentes no fermento de panificação, e que o melado fabricado desta forma atende às especificações sendo inclusive preferido entre os consumidores. Os resultados obtidos indicaram uma solução viável e de baixo custo para a produção de melados com teor de açúcares redutores em torno de 30% (com adição de 0,010% de fermento biológico seco instantâneo - FBSI), garantindo assim melhor estabilidade em relação à cristalização da sacarose., Revista de Ciências Agrárias, Vol. 42 No. 4 (2019)

Níveis intracelulares de G-3-PDH (sn-glicerol-3-fosfato:NAD+ 2oxidoredutase, EC 1.1.1.8) de levedura de panificação foram acompanhados durante a estocagem sob três diferentes temperaturas. Semelhantes valores de biomassa final e de atividade específica da enzima foram obtidos após crescimento por 48 horas de duas linhagens de leveduras de panificação. O melhor meio (meio indutor) para obtenção de G-3-PDH foi: extrato de levedura (1%,p/v), peptona (2%,p/v), glicerol (3%,v/v) e etanol (1%,v/v). O choque osmótico com adição de NaCl 0,6 M provocou aumento da atividade de G-3-PDH de 1,2 vezes para leveduras crescidas em meio indutor por 48 horas e transferidas para o meio salino, por 2 horas. A estocagem (até 10 dias) da linhagem de levedura GD0, sob temperatura ambiente (27 ºC) estimulou a síntese da G-3-PDH de células propagadas no meio indutor, lavadas e liofilizadas. Estocagens em geladeira (temperatura de 4 - 5 ºC) ou em ''freezer'' (temperatura de -18 ºC) mantiveram a atividade da G-3-PDH por até 8 meses.Intracellular levels of glycerol-3-phosphate dehydrogenase (G-3-PDH) in baker's yeasts were monitored during storage at 3 different temperatures. Similar values for final biomass and specific activity of the enzyme were found, in each of two strains of baker's yeast, after 48 hours growth. The best medium tested, for the induction of G-3-PDH, contained: yeast extract (1% w/v), peptone (2% w/v), glycerol (3% w/v)and ethanol (1% w/v). Osmotic shock, provoked by suspending cells, after 48 hours growth in inducing medium, in 0.6 M NaCl solution for 2 hours, caused the activity to increase by a factor of 1.2. Cells of the GDO yeast strain, grown in inducing conditions, washed and lyophilized, exhibited a 35% rise in G-3-PDH activity during storage (10 days) at ambient temperature (about 27 ºC). Both refrigeration (4-5 ºC) and freezer storage (-18 ºC) maintained the G-3-PDH activity for up to 8 months.

Made available in DSpace on 2014-06-11T19:23:26Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-07-28Bitstream added on 2014-06-13T19:29:24Z : No. of bitstreams: 1 aragon_cc_me_arafcf.pdf: 397051 bytes, checksum: e29ac6a4f5baf629041e6e9442044f9e (MD5) Universidade Estadual Paulista (UNESP) No presente trabalho, a atividade da enzima glicerol quinase (GK; EC 2.7.1.30; ATP: glicerol 3-fosfotransferase), proveniente de extratos de levedura seca de panificação, foi otimizada. A melhor preparação enzimática da GK foi obtida por rompimento celular com esferas de vidro, durante sete minutos, com lise de 54,2% das células. O extrato celular foi parcialmente purificado com 1% de sulfato de estreptomicina, antes da precipitação com igual volume de solução a 30% (m/v) de polietilenoglicol 3350, e posteriormente dialisado. A atividade máxima da GK foi obtida em pH 10,0, a 60ºC e 50mM de substrato, por metodologia clássica. A enzima apresentou alta estabilidade térmica ― a atividade foi completamente mantida até 50ºC, durante uma hora ― e em pH entre 6,0 e 8,0. Além disso, manteve-se estável, por quatro meses, a 4°C, na presença de azida de sódio 0,05% e cloreto de cobalto 10mM, e, por até oito meses, com o extrato liofilizado. Calculados pelos métodos de Lineweaver-Burk, Hanes-Woolf e Eadie-Hofstee, o valor da constante de Michaelis (Km) da enzima variou entre 1,99mM e 3,11mM, e a Vmax, entre 1,14U/mL e 1,19U/mL. Utilizou-se a metodologia de superfície de resposta (MSR) para melhor definição dos parâmetros da reação enzimática, observando-se valores ótimos de atividades a temperaturas entre 52ºC e 56ºC, pH entre 10,2 e 10,5 e concentração de substrato de 150mM a 170mM. A MSR mostrou-se adequada para modelar a reação e maximizar a atividade da glicerol quinase. Este método, de baixo custo, dosa a glicerol quinase em uma seqüência de reações, sendo de grande importância para diversas indústrias, como a de alimentos, açúcar e álcool. In the present study, the activity of the enzyme glycerol kinase (GK; EC 2.7.1.30; ATP: glycerol 3-phosphotransferase) from dry baker´s yeast, was optimized. The best enzymatic preparation of GK was obtained by cell disruption with glass beads, for seven minutes, with 54.2% of lysed cells. Cell extract was partially purified with 1% of streptomycin sulphate, before the precipitation with equal volume of a 30% solution (m/v) of polyethylene glycol 3350, and then it was dialyzed. The maximum activity of GK was obtained with pH 10.0, at 60ºC and 50mM of substrate, by the classic methodology. The enzyme presented high thermal stability ― the activity was completely maintained up to 50ºC, during one hour ― and at pH between 6.0 and 8.0. Besides, it was stable, for four months, at 4°C, in the presence of sodium azide 0.05% and cobalt chloride 10mM, and, for up to eight months, with the lyophilized extract. The value of the Michaelis constant (Km) of the enzyme was calculated by the methods of Lineweaver-Burk, Hanes-Woolf and Eadie-Hofstee,and it varied between 1.99mM and 3.11mM, and Vmax, between 1.14U/mL and 1.19U/mL. Response surface methodology (RSM) was used for better definition of the parameters of the enzymatic reaction, being observed higher activity values at temperatures between 52ºC and 56ºC, pH between 10.2 and 10.5 and substrate concentration from 150mM to 170mM. RSM showed to be an adequate approach for modeling the reaction and maximizing the glycerol kinase activity. This low cost method doses glycerol kinase in a sequence of reactions, being of great importance for many industries, like food, sugar and alcohol.

Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-27T11:22:05Z No. of bitstreams: 0Bitstream added on 2014-05-27T14:45:48Z : No. of bitstreams: 1 2-s2.0-35348993198.pdf: 77237 bytes, checksum: 2f0695884100b959e1c7c8a1d89a151d (MD5) Made available in DSpace on 2014-05-27T11:22:05Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-12-01 The synthesis of intracellular glycerol-3-phosphate dehydrogenase (EC 1.1.1.8) in baker's yeast was investigated in submerged culture supplied with glucose or glycerol as sole carbon sources. Inhibitors of the glycolytic pathway, Krebs cycle and respiratory chain did not stimulate glycerol-3-phosphate dehydrogenase synthesis when added in low concentrations in up 7.5 × 10 -5 mol/L. The repression exercised by glucose on the synthesis of glycerol-3-phosphate dehydrogenase in YP-glucose medium was reduced by the addition of fermentation products and of sodium bisulfite. Synthesis of the enzyme was raised 22-110%. However, in YP-glycerol medium, the addition of 0.06% (w/v) sodium bisulfite reduced (29%) the synthesis of the enzyme, while 0.012% (v/v) acetaldehyde stimulated the synthesis of glycerol-3-phosphate dehydrogenase by 12%. Departamento de Alimentos e Nutrição Faculdade de Ciências Farmacêuticas Universidade Estadual Paulista, UNESP, Araraquara, SP Departamento de Alimentos e Nutrição Faculdade de Ciências Farmacêuticas Universidade Estadual Paulista, UNESP, Rodovia Araraquara-Jaú, km 1, CEP 14801-902 - Araraquara - SP Departamento de Alimentos e Nutrição Faculdade de Ciências Farmacêuticas Universidade Estadual Paulista, UNESP, Araraquara, SP Departamento de Alimentos e Nutrição Faculdade de Ciências Farmacêuticas Universidade Estadual Paulista, UNESP, Rodovia Araraquara-Jaú, km 1, CEP 14801-902 - Araraquara - SP

The use of pheromones in integrated pest management has been increasing in the last years due to environmental concern. This development is accompanied by the search for simple, efficient and less aggressive synthetic methodologies for the preparation of pheromones. One of these methodologies includes microbiological reactions, more specifically biocatalytic reduction of carbonyl compounds using baker's yeast (Saccharomyces cerevisiae). This review presents the use of baker's yeast as an easy and cheap alternative to obtain enantiomerically enriched compounds employed in the synthesis of pheromones.

New methodologies for protection of Saccharomyces cerevisiae (FP) cells when supported in montmorillonite K10 (K10), recovered or not with gelatin (G) and in the presence or absence of sucrose (S) are presented. These systems were used for the enantioselective reduction of ethyl acetoacetate and a-chloroacetophenone in hexane, under FP/K10/G/S and FP/S at 20ºC during 24 hours, affording S-(+)-ethyl-3-hydroxybutanoate in 100% conversion and 99% ee, and R-(-)-2-chloro-1-phenylethanol 79% and 78% ee at 20 and 30 ºC, respectivelly.

Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2013-08-22T18:41:04Z No. of bitstreams: 1 S1516-93322002000100008.pdf: 156986 bytes, checksum: 4f02b30ea0995a50452213418d73cfba (MD5) Made available in DSpace on 2013-08-22T18:41:04Z (GMT). No. of bitstreams: 1 S1516-93322002000100008.pdf: 156986 bytes, checksum: 4f02b30ea0995a50452213418d73cfba (MD5) Previous issue date: 2002-03-01 Made available in DSpace on 2013-09-30T18:07:24Z (GMT). No. of bitstreams: 2 S1516-93322002000100008.pdf: 156986 bytes, checksum: 4f02b30ea0995a50452213418d73cfba (MD5) S1516-93322002000100008.pdf.txt: 25335 bytes, checksum: d8b7c44d177b4a168f8023772a31edf8 (MD5) Previous issue date: 2002-03-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T13:25:16Z No. of bitstreams: 2 S1516-93322002000100008.pdf: 156986 bytes, checksum: 4f02b30ea0995a50452213418d73cfba (MD5) S1516-93322002000100008.pdf.txt: 25335 bytes, checksum: d8b7c44d177b4a168f8023772a31edf8 (MD5) Made available in DSpace on 2014-05-20T13:25:16Z (GMT). No. of bitstreams: 2 S1516-93322002000100008.pdf: 156986 bytes, checksum: 4f02b30ea0995a50452213418d73cfba (MD5) S1516-93322002000100008.pdf.txt: 25335 bytes, checksum: d8b7c44d177b4a168f8023772a31edf8 (MD5) Previous issue date: 2002-03-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Níveis intracelulares de G-3-PDH (sn-glicerol-3-fosfato:NAD+ 2oxidoredutase, EC 1.1.1.8) de levedura de panificação foram acompanhados durante a estocagem sob três diferentes temperaturas. Semelhantes valores de biomassa final e de atividade específica da enzima foram obtidos após crescimento por 48 horas de duas linhagens de leveduras de panificação. O melhor meio (meio indutor) para obtenção de G-3-PDH foi: extrato de levedura (1%,p/v), peptona (2%,p/v), glicerol (3%,v/v) e etanol (1%,v/v). O choque osmótico com adição de NaCl 0,6 M provocou aumento da atividade de G-3-PDH de 1,2 vezes para leveduras crescidas em meio indutor por 48 horas e transferidas para o meio salino, por 2 horas. A estocagem (até 10 dias) da linhagem de levedura GD0, sob temperatura ambiente (27 ºC) estimulou a síntese da G-3-PDH de células propagadas no meio indutor, lavadas e liofilizadas. Estocagens em geladeira (temperatura de 4 - 5 ºC) ou em ''freezer'' (temperatura de -18 ºC) mantiveram a atividade da G-3-PDH por até 8 meses. Intracellular levels of glycerol-3-phosphate dehydrogenase (G-3-PDH) in baker's yeasts were monitored during storage at 3 different temperatures. Similar values for final biomass and specific activity of the enzyme were found, in each of two strains of baker's yeast, after 48 hours growth. The best medium tested, for the induction of G-3-PDH, contained: yeast extract (1% w/v), peptone (2% w/v), glycerol (3% w/v)and ethanol (1% w/v). Osmotic shock, provoked by suspending cells, after 48 hours growth in inducing medium, in 0.6 M NaCl solution for 2 hours, caused the activity to increase by a factor of 1.2. Cells of the GDO yeast strain, grown in inducing conditions, washed and lyophilized, exhibited a 35% rise in G-3-PDH activity during storage (10 days) at ambient temperature (about 27 ºC). Both refrigeration (4-5 ºC) and freezer storage (-18 ºC) maintained the G-3-PDH activity for up to 8 months. UNESP Faculdade de Ciências Farmacêuticas Departamento de Alimentos e Nutrição UNESP Faculdade de Ciências Farmacêuticas Departamento de Alimentos e Nutrição

Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2013-08-22T18:48:23Z No. of bitstreams: 1 S0100-40421997000500017.pdf: 61307 bytes, checksum: b0985930adce1b10f9cbed71188d8f9b (MD5) Made available in DSpace on 2013-08-22T18:48:23Z (GMT). No. of bitstreams: 1 S0100-40421997000500017.pdf: 61307 bytes, checksum: b0985930adce1b10f9cbed71188d8f9b (MD5) Previous issue date: 1997-10-01 Made available in DSpace on 2013-09-30T19:07:41Z (GMT). No. of bitstreams: 2 S0100-40421997000500017.pdf: 61307 bytes, checksum: b0985930adce1b10f9cbed71188d8f9b (MD5) S0100-40421997000500017.pdf.txt: 14613 bytes, checksum: eccb26f013f2b98a92ddaa9496894c52 (MD5) Previous issue date: 1997-10-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T14:17:50Z No. of bitstreams: 2 S0100-40421997000500017.pdf: 61307 bytes, checksum: b0985930adce1b10f9cbed71188d8f9b (MD5) S0100-40421997000500017.pdf.txt: 14613 bytes, checksum: eccb26f013f2b98a92ddaa9496894c52 (MD5) Made available in DSpace on 2014-05-20T14:17:50Z (GMT). No. of bitstreams: 2 S0100-40421997000500017.pdf: 61307 bytes, checksum: b0985930adce1b10f9cbed71188d8f9b (MD5) S0100-40421997000500017.pdf.txt: 14613 bytes, checksum: eccb26f013f2b98a92ddaa9496894c52 (MD5) Previous issue date: 1997-10-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) A model for the construction of a simple and cheap apparatus to be used as bioreactor for reactions catalyzed by baker's yeast (Saccharomyces cerevisiae) is described. The bioconversion and separation of cells from products and residual substrates are obtained at the same time. The reactions carried out in this type of reactor are faster than those catalyzed by immobilized cells. Yeast cells can be cultivated in this bioreactor operating with cell recycling at appropriated conditions using glucose and other nutrients. Universidade Estadual Paulista Instituto de Química Departamento de Bioquímica Universidade Estadual Paulista Instituto de Química Departamento de Bioquímica

A model for the construction of a simple and cheap apparatus to be used as bioreactor for reactions catalyzed by baker's yeast (Saccharomyces cerevisiae) is described. The bioconversion and separation of cells from products and residual substrates are obtained at the same time. The reactions carried out in this type of reactor are faster than those catalyzed by immobilized cells. Yeast cells can be cultivated in this bioreactor operating with cell recycling at appropriated conditions using glucose and other nutrients.

Made available in DSpace on 2020-12-10T17:59:40Z (GMT). No. of bitstreams: 0 Previous issue date: 1997-09-01 A model for the construction of a simple and cheap apparatus to be used as bioreactor for reactions catalyzed by baker's yeast (Saccharomyces cerevisiae) is described, The bioconversion and separation of cells from products and residual substrates are obtained at the same time, The reactions carried out in this type of reactor are faster than those catalyzed by immobilized cells, Yeast cells can be cultivated in this bioreactor operating with cell recycling at appropriated conditions using glucose and other nutrients.

Dissertação de mestrado em Engenharia Biológica, Esta tese teve como objectivos principais a elaboração e implementação de soluções para a planificação óptima de experiências de modo a resolver o problema da identificação na estimação de coeficientes de rendimento num modelo de fermento de padeiro. O objectivo final foi programar trajectórias de alimentação de substrato. As metodologias apresentadas para a identificação de coeficientes de rendimento envolvem medições completas do estado e visam a optimização da riqueza informativa da experiência, quantificada por índices relativos à matriz de informação de FISHER. Procurou projectar-se experiências que conduzissem a um máximo de informação através da programação do caudal de alimentação em glucose. O procedimento utilizado necessita de um conhecimento a priori dos coeficientes de rendimento e é independente das cinéticas de reacção. Foram, depois, realizadas experiências com o perfil de alimentação de glucose optimizado para determinação dos coeficientes de rendimento., The main objectives of this thesis were the development and implementation of solutions to achieve an optimum experimental design in order to solve the problem of identification in the estimation of yield coefficients af a baker’s yeast model. The final objective has been to program substrate feeding profiles. The methodologies developed in order to identify yield coefficients involve complete state measurements and aim at the optimisation of the informative richness of the experiment, quantified by indexes related to the concept of FISHER’s information matrix. An effort has been made to design experiments that would lead to a maximum of information by programming the glucose feeding rate. The procedure needs a priori knowledge of the yield coefficient values and it is independent of the growth kinetics. Finally, experiments were performed with the optimised glucose feeding profile in order to determine the yield coefficients., Cette thése a pour objectif l’élaboration et l’implémentation de solutions pour la planification optimale d’essais, pour résoudre le problème de l’identification dans l’éstimation de coefficients de rendement dans un modèle de levure de boulangerie. Le but es programmer trajectoires d’alimentation en substrat. Les méthodologies developpées pour l’identification des coefficients de rendement enveloppent la mesure de l’état complet et ont pour but d’optimiser la consistance informative de l’expérience, quantifiée par des indexes relatifs à la matrice de l’information de FISHER. La planification expérimentale est faite pour obtenir un maximum d’information à travers de la programmation du débit d’alimentation en glucose. Le procédé a besoin d’une connaissance a priori de coefficients de rendement et est idépendant des taux de croissance. Finalement, expériences sont realisées avec le profil d’alimentation de glucose optimisé pour déterminer les coefficients de rendement., Fundação para a Ciência e a Tecnologia (FCT) - PRAXIS XXI.