Caracterização, pré-tratamentos, hidrólises enzimáticas e fermentação alcoólica de sorgo biomassa [Sorghum bicolor (L.) Moench]
Autor(a) principal: | |
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Data de Publicação: | 2019 |
Tipo de documento: | Tese |
Idioma: | por |
Título da fonte: | Repositório Institucional da UFU |
Texto Completo: | https://repositorio.ufu.br/handle/123456789/25419 http://dx.doi.org/10.14393/ufu.te.2019.2023 |
Resumo: | Sorghum biomass (SB) is a kind of sorghum sensitive to photoperiod with high productivity in biomass, and higher content in polysaccharides (cellulose and hemicelluloses), becoming a promising crop for application in the production of second generation ethanol (2G ethanol) . In this context, in the first stage of this study, the efficiency of an enzymatic extract produced by solid state fermentation (SSF) was evaluated using a consortium between the fungi Aspergillus fumigatus SCBM6 and A. niger SCBM1 in the hydrolysis of crude SB and after the removal of extractives (SE). After SSF, with respect to hemicellulase production, maximum peaks of xylanase (375 U g -1) on day 4 and β-xylosidase (150 U g -1) were obtained on 2nd day of co-cultivation. For cellulases, peaks of production were observed on the 1st day of fermentation (80 U g-1) for β-glycosidase and on 6 day (80 U g-1) for endoglucanase (CMCase) and cellulase on filter paper (FPase) (4 U g-1). After the enzymatic hydrolysis using the extract produced by the fungal consortium, the xylose and glucose release increased in SE about 10x (2.5 gL-1 after 12 hours), indicating that the withdrawal of extractives positively influenced hydrolysis efficiency and yields in fermentable sugars. The extraction of the extractives also represented a positive factor for the decrease of the formation of inhibitor compounds of alcoholic fermentation, such as formic acid. In the second stage, the ethanol yield was evaluated from hydrolysates of sorghum biomass previously submitted to three different chemical pre-treatments (PTs): sodium hydroxide (NaOH-1 and 2%), hydrochloric acid (HCl = 0.34 and 1.5%) and alkaline hydrogen peroxide (H2O2-5 and 7.36%) using the commercial enzymes Celluclast 1.5 L (10FPU) and Novozym 188 (30CBU) in the hydrolysis and the yeast Pichia stipitis in the alcoholic fermentation. Among the evaluated PTs, PT with 7.36% H2O2 was the most efficient in lignin removal and preservation of the polysaccharide fraction. After the hydrolysis, it was observed that the xylose concentrations remained practically unchanged in the hydrolysates of SB ¨in natura¨ and SE (without extractives). However, in the pre-treated sorghum hydrolysates, a large increase in xylose concentration was observed, especially in the hydrolysates of pretreated HCl and H2O2 sorghum. This increase was even more significant in sorghum hydrolysates pretreated with 0.34% HCl and 5% H2O2. Regarding glucose, the sorghum pretreated with H2O2 favored the highest release of this monosaccharide after enzymatic hydrolysis. In addition, all hydrolysates showed low concentrations of inhibitors. After hydrolysis, the highest ethanol yields were obtained in fermentations carried out with the hydrolysates of SB pretreated with HCl (0.34 and 1.5%), obtaining 3.84 and 3, 61g.L-1 ethanol, corresponding respectively to 16.15 and 14.62% yield. The results indicated that sorghum biomass presents potential for use as raw material in the production of ethanol, opening prospects for additional studies in order to optimize the process and obtain more expressive yields in ethanol. |
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Caracterização, pré-tratamentos, hidrólises enzimáticas e fermentação alcoólica de sorgo biomassa [Sorghum bicolor (L.) Moench]Characterization, pre-treatments, enzymatic hydrolysis and alcoholic fermentation of sorghum biomass [Sorghum bicolor (L.) Moench]Culturas energéticasConsórcio enzimáticoMateriais lignocelulósicosBioetanolEnergy CropsEnzymatic consortiumLignocellulosic materialsBioethanolBiocombustívelCNPQ::CIENCIAS BIOLOGICAS::MICROBIOLOGIACNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICACNPQ::CIENCIAS AGRARIASSorghum biomass (SB) is a kind of sorghum sensitive to photoperiod with high productivity in biomass, and higher content in polysaccharides (cellulose and hemicelluloses), becoming a promising crop for application in the production of second generation ethanol (2G ethanol) . In this context, in the first stage of this study, the efficiency of an enzymatic extract produced by solid state fermentation (SSF) was evaluated using a consortium between the fungi Aspergillus fumigatus SCBM6 and A. niger SCBM1 in the hydrolysis of crude SB and after the removal of extractives (SE). After SSF, with respect to hemicellulase production, maximum peaks of xylanase (375 U g -1) on day 4 and β-xylosidase (150 U g -1) were obtained on 2nd day of co-cultivation. For cellulases, peaks of production were observed on the 1st day of fermentation (80 U g-1) for β-glycosidase and on 6 day (80 U g-1) for endoglucanase (CMCase) and cellulase on filter paper (FPase) (4 U g-1). After the enzymatic hydrolysis using the extract produced by the fungal consortium, the xylose and glucose release increased in SE about 10x (2.5 gL-1 after 12 hours), indicating that the withdrawal of extractives positively influenced hydrolysis efficiency and yields in fermentable sugars. The extraction of the extractives also represented a positive factor for the decrease of the formation of inhibitor compounds of alcoholic fermentation, such as formic acid. In the second stage, the ethanol yield was evaluated from hydrolysates of sorghum biomass previously submitted to three different chemical pre-treatments (PTs): sodium hydroxide (NaOH-1 and 2%), hydrochloric acid (HCl = 0.34 and 1.5%) and alkaline hydrogen peroxide (H2O2-5 and 7.36%) using the commercial enzymes Celluclast 1.5 L (10FPU) and Novozym 188 (30CBU) in the hydrolysis and the yeast Pichia stipitis in the alcoholic fermentation. Among the evaluated PTs, PT with 7.36% H2O2 was the most efficient in lignin removal and preservation of the polysaccharide fraction. After the hydrolysis, it was observed that the xylose concentrations remained practically unchanged in the hydrolysates of SB ¨in natura¨ and SE (without extractives). However, in the pre-treated sorghum hydrolysates, a large increase in xylose concentration was observed, especially in the hydrolysates of pretreated HCl and H2O2 sorghum. This increase was even more significant in sorghum hydrolysates pretreated with 0.34% HCl and 5% H2O2. Regarding glucose, the sorghum pretreated with H2O2 favored the highest release of this monosaccharide after enzymatic hydrolysis. In addition, all hydrolysates showed low concentrations of inhibitors. After hydrolysis, the highest ethanol yields were obtained in fermentations carried out with the hydrolysates of SB pretreated with HCl (0.34 and 1.5%), obtaining 3.84 and 3, 61g.L-1 ethanol, corresponding respectively to 16.15 and 14.62% yield. The results indicated that sorghum biomass presents potential for use as raw material in the production of ethanol, opening prospects for additional studies in order to optimize the process and obtain more expressive yields in ethanol.CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorTese (Doutorado)O sorgo biomassa (SB) é um tipo de sorgo sensível ao fotoperíodo com alta produtividade em biomassa e maior conteúdo em polissacarídeos (celulose e hemiceluloses), tornando-se uma cultura promissora para aplicação na produção de etanol de segunda geração (etanol 2G). Neste contexto, na primeira etapa desse estudo, avaliou-se a eficiência de um extrato enzimático produzido por fermentação em estado sólido (FES) utilizando um consórcio entre os fungos Aspergillus fumigatus SCBM6 e A. niger SCBM1 na hidrólise de SB bruto e após a retirada de extrativos (SE). Após a FES, com relação à produção de hemicelulases, foram obtidos picos máximos de xilanase (375 U g-1) no 4° dia e β-xilosidase (150 U g-1) no 2° dia de co-cultivo. Para celulases, os picos máximos de produção foram observados no 1° dia de fermentação (80 U g-1) para β-glicosidase e no 6° dia (80 U g-1) para endoglucanase (CMCase) e celulase em papel de filtro (FPase) (4 U g-1). Após a hidrólise enzimática utilizando o extrato produzido pelo consórcio fúngico, a liberação de xilose e glicose aumentou em SE cerca de 10x (2,5 g.L-1 após 12 horas), indicando que a retirada de extrativos influenciou positivamente na eficiência da hidrólise e nos rendimentos em açúcares fermentescíveis. A retirada dos extrativos também representou um fator positivo para a diminuição da formação de compostos inibidores da fermentação alcóolica, como o ácido fórmico. Na segunda etapa, foi avaliado o rendimento em etanol a partir de hidrolisados de sorgo biomassa previamente submetido a três diferentes pré-tratamentos químicos (PTs): hidróxido de sódio (NaOH - 1 e 2%), ácido clorídrico (HCl - 0,34 e 1,5%) e peróxido de hidrogênio alcalino (H2O2 - 5 e 7,36%) utilizando as enzimas comerciais Celluclast 1,5 L (10FPU) e Novozym 188 (30CBU) nas hidrólises e a levedura Pichia stipitis na fermentação alcóolica. Entre os PTs usados, o PT com H2O2 a 7,36% foi o mais eficiente na remoção de lignina e preservação da fração polissacarídica. Após as hidrólises, observou-se que as concentrações de xilose se mantiveram praticamente inalteradas nos hidrolisados de SB ¨in natura¨ e SE (sem extrativos). No entanto, nos hidrolisados de sorgo pré-tratado, observou-se um grande aumento na concentração de xilose, principalmente nos hidrolisados de sorgo pré-tratado com HCl e H2O2. Esse aumento foi ainda mais expressivo nos hidrolisados de sorgo pré-tratado com HCl 0,34% e com H2O2 5%. Com relação à glicose, a amostra de sorgo pré-tratado com H2O2 foi o que favoreceu a maior liberação desse monossacarídeo após a hidrólise enzimática. Além disso, todos os hidrolisados apresentaram baixas concentrações de inibidores. Após as hidrólises, os maiores rendimentos em etanol foram obtidos nas fermentações com os hidrolisados de SB pré-tratado com HCl (0,34 e 1,5%), obtendo-se 3,84 e 3,61g.L-1 de etanol, correspondendo respectivamente a 16,15 e 14,62% de rendimento. Os resultados obtidos indicaram que o sorgo biomassa apresenta potencial para utilização como matéria prima na produção de etanol e abrem perspectivas para estudos adicionais a fim de otimizar o processo e obter rendimentos ainda mais expressivos em etanol.Universidade Federal de UberlândiaBrasilPrograma de Pós-graduação em BiocombustíveisPasquini, Danielhttp://lattes.cnpq.br/6879704705300161Baffi, Milla Alveshttp://lattes.cnpq.br/2825584905077015Camargo, Reginaldo dehttp://lattes.cnpq.br/4114675395066315Ruggiero, Reinaldohttp://lattes.cnpq.br/4115787653873302Gurgel, Leandro Vinícius Alveshttp://lattes.cnpq.br/7680699374474730Baêta, Bruno Eduardo Lobohttp://lattes.cnpq.br/3757404884076274Santos, Beatriz Vieira dos2019-06-17T14:21:17Z2019-06-17T14:21:17Z2019-04-29info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/doctoralThesisapplication/pdfSANTOS, Beatriz Vieira dos. Caracterização, pré-tratamentos, hidrólises enzimáticas e fermentação alcoólica de sorgo biomassa [Sorghum bicolor (L.) Moench]. 2019. 103 f. Tese (Doutorado em Biocombustíveis) - Universidade Federal de Uberlândia, Uberlândia, 2019. DOI http://dx.doi.org/10.14393/ufu.te.2019.2023.https://repositorio.ufu.br/handle/123456789/25419http://dx.doi.org/10.14393/ufu.te.2019.2023porhttp://creativecommons.org/licenses/by-nc-nd/3.0/us/info:eu-repo/semantics/openAccessreponame:Repositório Institucional da UFUinstname:Universidade Federal de Uberlândia (UFU)instacron:UFU2019-06-18T06:06:30Zoai:repositorio.ufu.br:123456789/25419Repositório InstitucionalONGhttp://repositorio.ufu.br/oai/requestdiinf@dirbi.ufu.bropendoar:2019-06-18T06:06:30Repositório Institucional da UFU - Universidade Federal de Uberlândia (UFU)false |
dc.title.none.fl_str_mv |
Caracterização, pré-tratamentos, hidrólises enzimáticas e fermentação alcoólica de sorgo biomassa [Sorghum bicolor (L.) Moench] Characterization, pre-treatments, enzymatic hydrolysis and alcoholic fermentation of sorghum biomass [Sorghum bicolor (L.) Moench] |
title |
Caracterização, pré-tratamentos, hidrólises enzimáticas e fermentação alcoólica de sorgo biomassa [Sorghum bicolor (L.) Moench] |
spellingShingle |
Caracterização, pré-tratamentos, hidrólises enzimáticas e fermentação alcoólica de sorgo biomassa [Sorghum bicolor (L.) Moench] Santos, Beatriz Vieira dos Culturas energéticas Consórcio enzimático Materiais lignocelulósicos Bioetanol Energy Crops Enzymatic consortium Lignocellulosic materials Bioethanol Biocombustível CNPQ::CIENCIAS BIOLOGICAS::MICROBIOLOGIA CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA CNPQ::CIENCIAS AGRARIAS |
title_short |
Caracterização, pré-tratamentos, hidrólises enzimáticas e fermentação alcoólica de sorgo biomassa [Sorghum bicolor (L.) Moench] |
title_full |
Caracterização, pré-tratamentos, hidrólises enzimáticas e fermentação alcoólica de sorgo biomassa [Sorghum bicolor (L.) Moench] |
title_fullStr |
Caracterização, pré-tratamentos, hidrólises enzimáticas e fermentação alcoólica de sorgo biomassa [Sorghum bicolor (L.) Moench] |
title_full_unstemmed |
Caracterização, pré-tratamentos, hidrólises enzimáticas e fermentação alcoólica de sorgo biomassa [Sorghum bicolor (L.) Moench] |
title_sort |
Caracterização, pré-tratamentos, hidrólises enzimáticas e fermentação alcoólica de sorgo biomassa [Sorghum bicolor (L.) Moench] |
author |
Santos, Beatriz Vieira dos |
author_facet |
Santos, Beatriz Vieira dos |
author_role |
author |
dc.contributor.none.fl_str_mv |
Pasquini, Daniel http://lattes.cnpq.br/6879704705300161 Baffi, Milla Alves http://lattes.cnpq.br/2825584905077015 Camargo, Reginaldo de http://lattes.cnpq.br/4114675395066315 Ruggiero, Reinaldo http://lattes.cnpq.br/4115787653873302 Gurgel, Leandro Vinícius Alves http://lattes.cnpq.br/7680699374474730 Baêta, Bruno Eduardo Lobo http://lattes.cnpq.br/3757404884076274 |
dc.contributor.author.fl_str_mv |
Santos, Beatriz Vieira dos |
dc.subject.por.fl_str_mv |
Culturas energéticas Consórcio enzimático Materiais lignocelulósicos Bioetanol Energy Crops Enzymatic consortium Lignocellulosic materials Bioethanol Biocombustível CNPQ::CIENCIAS BIOLOGICAS::MICROBIOLOGIA CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA CNPQ::CIENCIAS AGRARIAS |
topic |
Culturas energéticas Consórcio enzimático Materiais lignocelulósicos Bioetanol Energy Crops Enzymatic consortium Lignocellulosic materials Bioethanol Biocombustível CNPQ::CIENCIAS BIOLOGICAS::MICROBIOLOGIA CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA CNPQ::CIENCIAS AGRARIAS |
description |
Sorghum biomass (SB) is a kind of sorghum sensitive to photoperiod with high productivity in biomass, and higher content in polysaccharides (cellulose and hemicelluloses), becoming a promising crop for application in the production of second generation ethanol (2G ethanol) . In this context, in the first stage of this study, the efficiency of an enzymatic extract produced by solid state fermentation (SSF) was evaluated using a consortium between the fungi Aspergillus fumigatus SCBM6 and A. niger SCBM1 in the hydrolysis of crude SB and after the removal of extractives (SE). After SSF, with respect to hemicellulase production, maximum peaks of xylanase (375 U g -1) on day 4 and β-xylosidase (150 U g -1) were obtained on 2nd day of co-cultivation. For cellulases, peaks of production were observed on the 1st day of fermentation (80 U g-1) for β-glycosidase and on 6 day (80 U g-1) for endoglucanase (CMCase) and cellulase on filter paper (FPase) (4 U g-1). After the enzymatic hydrolysis using the extract produced by the fungal consortium, the xylose and glucose release increased in SE about 10x (2.5 gL-1 after 12 hours), indicating that the withdrawal of extractives positively influenced hydrolysis efficiency and yields in fermentable sugars. The extraction of the extractives also represented a positive factor for the decrease of the formation of inhibitor compounds of alcoholic fermentation, such as formic acid. In the second stage, the ethanol yield was evaluated from hydrolysates of sorghum biomass previously submitted to three different chemical pre-treatments (PTs): sodium hydroxide (NaOH-1 and 2%), hydrochloric acid (HCl = 0.34 and 1.5%) and alkaline hydrogen peroxide (H2O2-5 and 7.36%) using the commercial enzymes Celluclast 1.5 L (10FPU) and Novozym 188 (30CBU) in the hydrolysis and the yeast Pichia stipitis in the alcoholic fermentation. Among the evaluated PTs, PT with 7.36% H2O2 was the most efficient in lignin removal and preservation of the polysaccharide fraction. After the hydrolysis, it was observed that the xylose concentrations remained practically unchanged in the hydrolysates of SB ¨in natura¨ and SE (without extractives). However, in the pre-treated sorghum hydrolysates, a large increase in xylose concentration was observed, especially in the hydrolysates of pretreated HCl and H2O2 sorghum. This increase was even more significant in sorghum hydrolysates pretreated with 0.34% HCl and 5% H2O2. Regarding glucose, the sorghum pretreated with H2O2 favored the highest release of this monosaccharide after enzymatic hydrolysis. In addition, all hydrolysates showed low concentrations of inhibitors. After hydrolysis, the highest ethanol yields were obtained in fermentations carried out with the hydrolysates of SB pretreated with HCl (0.34 and 1.5%), obtaining 3.84 and 3, 61g.L-1 ethanol, corresponding respectively to 16.15 and 14.62% yield. The results indicated that sorghum biomass presents potential for use as raw material in the production of ethanol, opening prospects for additional studies in order to optimize the process and obtain more expressive yields in ethanol. |
publishDate |
2019 |
dc.date.none.fl_str_mv |
2019-06-17T14:21:17Z 2019-06-17T14:21:17Z 2019-04-29 |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/doctoralThesis |
format |
doctoralThesis |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
SANTOS, Beatriz Vieira dos. Caracterização, pré-tratamentos, hidrólises enzimáticas e fermentação alcoólica de sorgo biomassa [Sorghum bicolor (L.) Moench]. 2019. 103 f. Tese (Doutorado em Biocombustíveis) - Universidade Federal de Uberlândia, Uberlândia, 2019. DOI http://dx.doi.org/10.14393/ufu.te.2019.2023. https://repositorio.ufu.br/handle/123456789/25419 http://dx.doi.org/10.14393/ufu.te.2019.2023 |
identifier_str_mv |
SANTOS, Beatriz Vieira dos. Caracterização, pré-tratamentos, hidrólises enzimáticas e fermentação alcoólica de sorgo biomassa [Sorghum bicolor (L.) Moench]. 2019. 103 f. Tese (Doutorado em Biocombustíveis) - Universidade Federal de Uberlândia, Uberlândia, 2019. DOI http://dx.doi.org/10.14393/ufu.te.2019.2023. |
url |
https://repositorio.ufu.br/handle/123456789/25419 http://dx.doi.org/10.14393/ufu.te.2019.2023 |
dc.language.iso.fl_str_mv |
por |
language |
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http://creativecommons.org/licenses/by-nc-nd/3.0/us/ info:eu-repo/semantics/openAccess |
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http://creativecommons.org/licenses/by-nc-nd/3.0/us/ |
eu_rights_str_mv |
openAccess |
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application/pdf |
dc.publisher.none.fl_str_mv |
Universidade Federal de Uberlândia Brasil Programa de Pós-graduação em Biocombustíveis |
publisher.none.fl_str_mv |
Universidade Federal de Uberlândia Brasil Programa de Pós-graduação em Biocombustíveis |
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reponame:Repositório Institucional da UFU instname:Universidade Federal de Uberlândia (UFU) instacron:UFU |
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Universidade Federal de Uberlândia (UFU) |
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UFU |
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UFU |
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Repositório Institucional da UFU |
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Repositório Institucional da UFU - Universidade Federal de Uberlândia (UFU) |
repository.mail.fl_str_mv |
diinf@dirbi.ufu.br |
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