Análise das linhagens de Saccharomyces cerevisiae expostas ao estresse por etanol
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Data
2017-12-04
Autores
Almeida, Lauana Fogaça de
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Universidade Estadual Paulista (Unesp)
Resumo
O bioetanol é o biocombustível mais utilizado no mundo, tendo como uma de suas principais vantagens o fato de contribuir para a redução da emissão de gases do efeito estufa. O principal organismo fermentador utilizado para a produção de bioetanol é a levedura Saccharomyces cerevisiae, que quando adicionada num meio com glicose ou outra fonte de carbono fermentável, utilizará a fermentação alcoólica como processo metabólico principal para a obtenção de energia e consequentemente o etanol. No presente trabalho testou-se 14 linhagens de S. cerevisiae, analisando o grau máximo de tolerância ao etanol bem como características celulares e moleculares. Para isso foi utilizado técnicas como citometria de fluxo, curvas de crescimento e analises de proteômica. O objetivo do trabalho foi analisar as proteínas mais abundantes, em um contexto comparativo para os experimentos de estresse máximo por etanol nas leveduras, identificando enzimas chaves presentes durante o tratamento e possivelmente responsável pela tolerância. Foram determinadas as concentrações máximas de etanol suportada por cada linhagem seguida por análises de viabilidade celular. Os resultados demonstraram que a capacidade de replicação e viabilidade celular não estão diretamente ligados ao fenômeno de tolerância. Além disso, a presença de proteínas relacionadas às vias fermentativas, vias oxidativas e manutenção da homeostase celular, parecem estar associadas a um perfil de maior tolerância ao etanol uma vez que estão mais abundantes nas linhagens mais tolerantes. Também, evidenciou-se que qualidades como tolerância e resistência ilustram diferentes papeis nas cepas estudadas, pois linhagens que apresentam uma maior tolerância ao etanol nem sempre são as mais resistentes.
Bioethanol is the most used biofuel in the world since its main advantage is the reduction of greenhouse gas emissions. The most used organism for bioethanol production is the yeast Saccharomyces cerevisiae, which uses glucose, or other fermentable carbon sources, for energy obtaining and ethanol production from the alcoholic fermentation pathway. In this work, 14 S. cerevisiae strains were evaluated concerning their highest ethanol tolerance degree and cellular/molecular characteristics as well. For this purpose, it was used techniques such as flow cytometry, growth curve analysis and proteomics. The objective of this work was to analyze the most abundant proteins, in a comparative context of maximum ethanol stress for yeasts, to identify keyenzymes present during cell treatments as well as their possible influence for the ethanol tolerance. Before that, it was determined the highest ethanol concentration each strain could support followed by cellular viabilities. The results demonstrated that replication capacity and cell viability are not closely related to the ethanol tolerance. Moreover, the presence of proteins related to fermentative pathways, oxidative pathways, and maintenance of cellular homeostasis, looks like to be linked to the highest ethanol tolerance profile, since those proteins are more present in higher ethanol tolerant strains. Furthermore, it was possible to understand that both tolerance and resistance features play different roles in the studied strains, since the higher ethanol tolerant strains always are not the most resistant ones.
Bioethanol is the most used biofuel in the world since its main advantage is the reduction of greenhouse gas emissions. The most used organism for bioethanol production is the yeast Saccharomyces cerevisiae, which uses glucose, or other fermentable carbon sources, for energy obtaining and ethanol production from the alcoholic fermentation pathway. In this work, 14 S. cerevisiae strains were evaluated concerning their highest ethanol tolerance degree and cellular/molecular characteristics as well. For this purpose, it was used techniques such as flow cytometry, growth curve analysis and proteomics. The objective of this work was to analyze the most abundant proteins, in a comparative context of maximum ethanol stress for yeasts, to identify keyenzymes present during cell treatments as well as their possible influence for the ethanol tolerance. Before that, it was determined the highest ethanol concentration each strain could support followed by cellular viabilities. The results demonstrated that replication capacity and cell viability are not closely related to the ethanol tolerance. Moreover, the presence of proteins related to fermentative pathways, oxidative pathways, and maintenance of cellular homeostasis, looks like to be linked to the highest ethanol tolerance profile, since those proteins are more present in higher ethanol tolerant strains. Furthermore, it was possible to understand that both tolerance and resistance features play different roles in the studied strains, since the higher ethanol tolerant strains always are not the most resistant ones.
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Tolerância ao etanol, Saccharomyces cerevisiae, estresse ao etanol, Ethanol tolerance, Saccharomyces cerevisiae, ethanol stress