Estudo proteômico para o desenvolvimento de novas linhagens padrões de Saccharomyces cerevisiae de alto rendimento na fermentação alcoólica
Carregando...
Data
2018-12-04
Autores
Lacerda, Maria Priscila Franco
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
As células eucarióticas desenvolveram diversas estratégias para combater os efeitos nocivos de uma variedade de condições estressantes. Linhagens de Saccharomyces cerevisiae tem uma capacidade inata de suportar altos níveis de etanol que se tornariam letais ou prejudiciais à fisiologia de outros organismos. A resposta de estresse sob alta concentração de etanol em S. cerevisiae é importante em reações de fermentação e opera através da superexpressão e subexpressão de genes, alterando o perfil proteico e podendo resultar em perturbações do bioprocesso. O objetivo deste estudo foi determinar as diferenças no metabolismo de cada cepa de levedura visando à obtenção de informações a respeito da resistência à alta concentração de etanol a 12%. Para isso, as linhagens industriais PE-2 e CAT-1, e a linhagem Y12632 de S. cerevisiae isolada de processo de produção de etanol, foram utilizadas para a realização de testes em meio sintético contendo etanol 12%, simulando uma situação de estresse ocorrente em processos industriais para produção de etanol. Sendo assim, para avaliar essa resposta durante o estresse, a caracterização do processo fermentativo e a análise de integridade da membrana celular foram relacionadas à análise proteômica por shotgun. Principalmente através da avaliação de integridade da membrana citoplasmática, a cepa PE-2 demonstrou elevada resistência, além de alto consumo de substrato durante a fermentação com estresse induzido em comparação com a cepa industrial CAT-1, e a cepa selvagem Y12632. Em paralelo, a partir da análise proteômica foi possível a identificação de possíveis características que podem estar ligadas ao melhor perfil de resistência da cepa PE-2, como as funções de filamento de actina e metiltransferase com maior enriquecimento funcional no tempo de 4h em estresse, proteínas transportadoras transmembranares de substâncias, a proteína TPS1 (Biossíntese da trealose), assim como a Biossíntese de O-glican e glicanos (manose) no que diz respeito às vias metabólicas. Vale a pena ressaltar que para as três cepas analisadas as funções moleculares relacionadas às proteínas exclusivas de membrana estão fortemente relacionadas com funções transportadoras quando submetidas ao estresse ao etanol. Sugerindo assim, que o estresse ao etanol possa ter induzido maior atividade de proteínas transportadoras, cuja função está sendo cada vez mais exaltada em processos biotecnológicos. Outro ponto de evidência neste estudo foi a identificação de proteínas que interagem com proteínas já associadas ao estresse a etanol na literatura, essa integração fornece um melhor entendimento e usabilidade das redes preditas, o que pode ser valioso para seleção de novos alvos biológicos potenciais para o desenvolvimento de cepas resistentes ao estresse a etanol durante processos fermentativos.
Eukaryotic cells have developed several strategies to combat the harmful effects of a variety of stressful conditions. Strains of Saccharomyces cerevisiae have an innate ability to withstand high levels of ethanol that are usually lethal or detrimental to the physiology of other organisms. The stress response under high ethanol concentration in S. cerevisiae, which is important for fermentation reactions, promotes up or downregulation of some genes, that results in alterations in protein profile. The objective of this study was to determine the differences in the metabolism of each strain of yeast aiming to obtain information about resistance to high concentration of ethanol (12%). For this, two industrial strains, PE-2 and CAT-1, and one wild strain (Y12632), isolated from the ethanol production process, from S. cerevisiae were used to perform tests in synthetic medium containing 12% of ethanol, simulating a stress situation that occurs in industrial processes during the production of ethanol. Thus, the evaluation of response during stress, the characterization of the fermentative process and the analysis of cellular membrane integrity were related to the proteomic analysis by shotgun. Particularly through the evaluation of cytoplasmic membrane integrity, the PE-2 strain demonstrated high resistance, as well as high substrate consumption during induced stress fermentation, compared to the CAT-1 industrial strain and the wild strain Y12632. In paralell, from the proteomic analysis it was possible to identify possible characteristics that may be related to the best resistance profile of the PE-2 strain, such as the actin filament and methyltransferase functions with the highest functional enrichment in the time of 4h in stress, transmembrane substance transporter proteins, the TPS1 protein (Trehalose biosynthesis), as well as the biosynthesis of O-glycan and glycans (mannose) with respect to the metabolic pathways. It is worth mentioning that for the three analyzed strains the molecular functions related to membrane-exclusive proteins are strongly related to transport functions when subjected to ethanol stress. Thus, the stress on ethanol may have induced greater activity of transport proteins, whose function is being increasingly exalted in biotechnological processes. Another point of evidence in this study was the identification of proteins that interact with proteins already associated with ethanol stress in the literature, this integration provides a better understanding and usability of the predicted networks, which may be valuable for the selection of new potential biological targets for the development of stress resistant strains to ethanol during fermentative processes.
Eukaryotic cells have developed several strategies to combat the harmful effects of a variety of stressful conditions. Strains of Saccharomyces cerevisiae have an innate ability to withstand high levels of ethanol that are usually lethal or detrimental to the physiology of other organisms. The stress response under high ethanol concentration in S. cerevisiae, which is important for fermentation reactions, promotes up or downregulation of some genes, that results in alterations in protein profile. The objective of this study was to determine the differences in the metabolism of each strain of yeast aiming to obtain information about resistance to high concentration of ethanol (12%). For this, two industrial strains, PE-2 and CAT-1, and one wild strain (Y12632), isolated from the ethanol production process, from S. cerevisiae were used to perform tests in synthetic medium containing 12% of ethanol, simulating a stress situation that occurs in industrial processes during the production of ethanol. Thus, the evaluation of response during stress, the characterization of the fermentative process and the analysis of cellular membrane integrity were related to the proteomic analysis by shotgun. Particularly through the evaluation of cytoplasmic membrane integrity, the PE-2 strain demonstrated high resistance, as well as high substrate consumption during induced stress fermentation, compared to the CAT-1 industrial strain and the wild strain Y12632. In paralell, from the proteomic analysis it was possible to identify possible characteristics that may be related to the best resistance profile of the PE-2 strain, such as the actin filament and methyltransferase functions with the highest functional enrichment in the time of 4h in stress, transmembrane substance transporter proteins, the TPS1 protein (Trehalose biosynthesis), as well as the biosynthesis of O-glycan and glycans (mannose) with respect to the metabolic pathways. It is worth mentioning that for the three analyzed strains the molecular functions related to membrane-exclusive proteins are strongly related to transport functions when subjected to ethanol stress. Thus, the stress on ethanol may have induced greater activity of transport proteins, whose function is being increasingly exalted in biotechnological processes. Another point of evidence in this study was the identification of proteins that interact with proteins already associated with ethanol stress in the literature, this integration provides a better understanding and usability of the predicted networks, which may be valuable for the selection of new potential biological targets for the development of stress resistant strains to ethanol during fermentative processes.
Descrição
Palavras-chave
leveduras, fermentação, metabolismo, proteômica, yeasts