Adaptation Strategy to Increase the Tolerance of Scheffersomyces stipitis NRRL Y-7124 to Inhibitors of Sugarcane Bagasse Hemicellulosic Hydrolysate Through Comparative Studies of Proteomics and Fermentation

Autor(es)

Biazi, Luiz E. ; Santos, Samantha C. ; Neto, Antonio A. Kaupert ; Sousa, Amanda S. ; Soares, Lauren B. ; Renzano, Eduardo ; Velasco, Juliana ; Rabelo, Sarita C. ; Costa, Aline C. ; Ienczak, Jaciane L.

• Tipo de documento: Artigo Científico
• Fonte: BioEnergy Research; v. 15, n. 1, p. 14-pg., 2021-03-10.

Resumo

In this work, we propose an adaptation strategy for Scheffersomyces stipitis NRRL Y-7124 to increase its tolerance to inhibitors of hemicellulosic hydrolysates in the production of bioethanol. Sugarcane bagasse pretreated with 0.5% (v/v) of sulfuric acid at 140 degrees C for 15 min was used as feedstock. The microorganism was subjected to a cell recycle batch fermentation system with increased inhibitors pressure, characterized by five consecutive batches with 33% of hydrolysate, followed by five subsequent batches with 67% of hydrolysate. The remaining composition of the culture media for each sequential batch (necessary to complete 100% of carbohydrate content) was synthetic substrate. Finally, the strain was used in a fed-batch fermentation with 100% of hydrolysate, resulting in an adapted strain of S. stipitis at the end. In order to validate the adaptation strategy, the fermentative performances of the adapted and non-adapted strains were compared under different acetic acid concentrations using synthetic substrate. 0.7 g/L of acetic acid significantly affected the fermentative performance of the non-adapted strain, while for the adapted strain, this value was 3.7-fold higher (2.6 g/L), confirming the increased tolerance. Through proteomic analysis, genes related to the defense mechanisms of S. stipitis against oxidative stress due to the presence of inhibitory compounds were identified, which plays a key role on the comprehension of the cell adaptation metabolism. (AU)

• Processo FAPESP: 14/01135-0 - Produção de bioetanol de segunda geração em biorreatores intensificados a partir de cepas de Scheffersomyces stipitis melhoradas por evolução induzida
• Beneficiário: Samantha Christine Santos
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 16/14567-0 - Modelagem matemática do processo de produção de bioetanol de segunda geração com reciclo de células utilizando os microrganismos Scheffersomyces stipitis e Spathaspora passalidarum
• Beneficiário: Luiz Eduardo Biazi
• Modalidade de apoio: Bolsas no Brasil - Doutorado Direto
• Processo FAPESP: 15/20630-4 - Desenvolvimento integrado de biorrefinaria e planta de bioetanol de cana-de-açúcar com emissão zero de CO2: rotas para converter recursos renováveis em bioprodutos e bioeletricidade
• Beneficiário: Rubens Maciel Filho
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 17/04997-0 - Avaliação de leveduras nativas Scheffersomyces stipitis e Spathaspora passalidarum na produção de bioetanol de segunda geração a partir de hidrolisados de bagaço de cana-de-açúcar contendo xilose e glicose
• Beneficiário: Jaciane Lutz Ienczak
• Modalidade de apoio: Auxílio à Pesquisa - Regular