Evaluation of oxygen availability on ethanol production from sugarcane bagasse hydrolysate in a batch bioreactor using two strains of xylose-fermenting yeast

Dussán, Kelly J.; Silva, Débora da V.; Pérez, Víctor Haber; Silva, Sílvio Silvério da

doi:10.1016/j.renene.2015.10.065

Cited by 55 publications

(34 citation statements)

References 36 publications

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“…Como também pode ser observado na Tabela 1, no bagaço "in natura" a fração hemicelulósica representou 21,83 %, enquanto a celulose correspondeu à 32,49 % da sua composição. Estes valores apresentam algumas diferenças quando comparados aos resultados obtidos por Dussán et al (2016) Tabela 2 -Matriz do planejamento fatorial 2 2 -face centrada com três repetições no ponto central para estudo da influência das variáveis: concentração de NaOH e tempo de reação na etapa de deslignificação do bagaço de cana-de-açúcar pré-tratado com ácido diluído. Níveis codificados em parêntesis.…”

Section: Resultsunclassified

“…As melhores condições de pré-tratamento devem ser definidas como aquelas em que há recuperação máxima dos açúcares solúveis em água, a partir da hemicelulose (hidrolisado hemicelulósico), juntamente com a produção do melhor substrato possível (celulignina) para seu posterior aproveitamento. Um dos pré-tratamentos mais utilizados tem sido com ácido sulfúrico diluído, principalmente em função da sua eficiência no processo de separação dos componentes da parede celular (Canilha et al, 2010;Dussán et al, 2016). Numa segunda etapa, para a disponibilização da celulose presente na celulignina, estudos têm demonstrado a necessidade de uma etapa de deslignificação a qual tem sido realizada empregando-se hidróxido de sódio como catalisador.…”

Section: Introductionunclassified

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Deslignificação Do Bagaço De Cana-De-Açúcar Visando a Produção De Etanol Celulósico

Mello¹,

Mendes²,

Silva³

et al. 2017

Blucher Chemical Engineering Proceedings

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RESUMO -A produção de etanol celulósico (2G), obtido de biomassas vegetais, ainda apresenta desafios tecnológicos para que se torne competitiva ao etanol obtido do caldo de cana (1G). Estes vão desde a etapa de despolimerização da parede vegetal para solubilização dos açúcares das frações C6 e C5, com mínima liberação de compostos tóxicos, até a disponibilidade de micro-organismos capazes de fermentar estes açúcares, quesitos estes primordiais para o sucesso da tecnologia de obtenção de etanol a partir do bagaço de cana-de-açúcar. Para tanto se faz necessário o uso de pré-tratamentos químicos e enzimáticos (enzimas de baixo custo para hidrolisar a fração celulósica) no processamento do bagaço para a obtenção de açúcares solúveis a partir da matriz de celulignina que serão utilizados na posterior conversão em etanol por processos fermentativos. O uso da etapa de deslignificação do bagaço pré-tratado é de grande interesse para a obtenção de glicose pela ação das enzimas devido à maior disponibilidade da celulose. Portanto, o objetivo deste trabalho foi otimizar as condições operacionais da etapa de tratamento alcalino do bagaço de cana-de-açúcar pré-tratado, utilizando hidróxido de sódio, para se obter uma biomassa com maior conteúdo de celulose. Os resultados mostraram que a deslignificação foi mais eficiente quando foram empregados 2,2 % (p/v) de NaOH durante 100 min. a 110 ºC, obtendo-se um material com 85 % de celulose.

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Section: Resultsunclassified

Section: Introductionunclassified

Deslignificação Do Bagaço De Cana-De-Açúcar Visando a Produção De Etanol Celulósico

Mello¹,

Mendes²,

Silva³

et al. 2017

Blucher Chemical Engineering Proceedings

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“…Subsequently, 1 mg Cg AKR-1 and NADPH (2 µM) were added to the reaction and incubated at 30 °C for 16 h. After incubation, hemicellulosic hydrolysate alcoholic fermentation was performed. The yeast used in this study was the wild-type S. stipitis NRRL Y7124 strain, a xylose-fermenting microorganism capable to ferment the hemicellulosic hydrolysate [79, 80]. During this process, 3 g/L yeast extract was added to the liquor, and S. stipitis yeast was inoculated at a final concentration of 10 g/L in 50 mL; the hemicellulosic hydrolysate was present at a final dilution of 4× (+-xylose, 50 g/L).…”

Section: Methodsmentioning

confidence: 99%

“…During this process, 3 g/L yeast extract was added to the liquor, and S. stipitis yeast was inoculated at a final concentration of 10 g/L in 50 mL; the hemicellulosic hydrolysate was present at a final dilution of 4× (+-xylose, 50 g/L). Thereafter, the experiment was incubated at 30 °C with continuous agitation at 200 rpm for 72 h, as described by Dussán et al [81], using shake flasks. Glucose, xylose, acetic acid, glycerol, xylitol, furfural, and ethanol were measured during the fermentation according to the analytical measurements described below.…”

Section: Methodsmentioning

confidence: 99%

The Coptotermes gestroi aldo–keto reductase: a multipurpose enzyme for biorefinery applications

Tramontina

Cairo

Liberato

et al. 2017

Biotechnol Biofuels

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BackgroundIn nature, termites can be considered as a model biological system for biofuel research based on their remarkable efficiency for lignocellulosic biomass conversion. Redox enzymes are of interest in second-generation ethanol production because they promote synergic enzymatic activity with classical hydrolases for lignocellulose saccharification and inactivate fermentation inhibitory compounds produced after lignocellulose pretreatment steps.ResultsIn the present study, the biochemical and structural characteristics of the Coptotermes gestroi aldo–keto reductase (CgAKR-1) were comprehensively investigated. CgAKR-1 displayed major structural differences compared with others AKRs, including the differences in the amino acid composition of the substrate-binding site, providing basis for classification as a founding member of a new AKR subfamily (family AKR1 I). Immunolocalization assays with anti-CgAKR-1 antibodies resulted in strong fluorescence in the salivary gland, proventriculus, and foregut. CgAKR-1 supplementation caused a 32% reduction in phenolic aldehydes, such as furfural, which act as fermentation inhibitors of hemicellulosic hydrolysates, and improved ethanol fermentation by the xylose-fermenting yeast Scheffersomyces stipitis by 45%. We observed synergistic enzymatic interactions between CgAKR-1 and commercial cellulosic cocktail for sugarcane bagasse saccharification, with a maximum synergism degree of 2.17 for sugar release. Our data indicated that additive enzymatic activity could be mediated by reactive oxygen species because CgAKR-1 could produce hydrogen peroxide.ConclusionIn summary, we identified the founding member of an AKRI subfamily with a potential role in the termite digestome. CgAKR-1 was found to be a multipurpose enzyme with potential biotechnological applications. The present work provided a basis for the development and application of integrative and multipurpose enzymes in the bioethanol production chain.Electronic supplementary materialThe online version of this article (doi:10.1186/s13068-016-0688-6) contains supplementary material, which is available to authorized users.

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“…Xylose, the main degradation product from hemicellulose, is the second most abundant sugar in lignocellulose (Dussán et al 2016). Clearly, efficient conversion of xylose, together with cellulose-derived glucose into ethanol is essential to reduce the cost per unit of ethanol produced (Sassner et al 2008).…”

Section: Introductionmentioning

confidence: 99%

Hybridization Improves Inhibitor Tolerance of Xylose-fermenting Saccharomyces cerevisiae

Li¹,

Zhu²,

Li³

et al. 2017

BioResources

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Although some engineered S. cerevisiae strains exhibit good xylose utilization ability, the lack of tolerance to inhibitors generated in biomass pretreatment limits the application of such strains in the production of bioethanol from lignocellulosic biomass. By applying a sexual mating method, inhibitor tolerance was developed in xylose-utilizing strains. The final ethanol concentrations in simultaneous scarification and cofermentation (SScF) process at 38 °C with hybrid strains were 50% higher than the SScF process with the xylose-fermenting parent strain. The strain viability of the hybrid strain E7-12 at 24 h was 282 times higher than the parent strain in the SScF process at 25% solid loading. Due to the improved sugar utilization, the final ethanol concentration reached 69.7 g/L (E7-11) and 70.0 g/L (E7-12), which were 25.3 g/L and 25.6 g/L higher than that of SScF with the xylose-fermenting strain, respectively.

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Evaluation of oxygen availability on ethanol production from sugarcane bagasse hydrolysate in a batch bioreactor using two strains of xylose-fermenting yeast

Cited by 55 publications

References 36 publications

Deslignificação Do Bagaço De Cana-De-Açúcar Visando a Produção De Etanol Celulósico

Deslignificação Do Bagaço De Cana-De-Açúcar Visando a Produção De Etanol Celulósico

The Coptotermes gestroi aldo–keto reductase: a multipurpose enzyme for biorefinery applications

Hybridization Improves Inhibitor Tolerance of Xylose-fermenting Saccharomyces cerevisiae

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