Acidogenic fermentation of brewer’s spent grain towards polyhydroxyalkanoates production
Main Author: | |
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Publication Date: | 2017 |
Format: | Master thesis |
Language: | eng |
Source: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Download full: | http://hdl.handle.net/10362/25156 |
Summary: | Polyhydroxyalkanoates (PHA) are fully biodegradable polyesters, synthesized by microorganisms from renewable resources, which reveal an alternative to petroleum-based plastics. Its production by mixed microbial cultures, unlike pure cultures, allows the use of industrial by-products in the absence of sterility conditions, potentially reducing process costs. The study described focused on the valorization of a waste from a brewery industry, brewer’s spent grain (BSG), through organic acids production, towards PHA production. PHA production using mixed microbial cultures involves three steps: (1) acidogenic fermentation of BSG for organic acids production, (2) selection of the mixed cultures able to accumulate PHA and (3) PHA production. In order to extract the sugars necessary to produce organic acids (phase 1), pre-treatment methods such as acid hydrolysis and subcritical water have been studied. Acid hydrolysis was selected for further experiments as the hydrolysis yield on sugars reached was higher than using subcritical water (0.152 g total sugars g BSG-1 versus 0.008 and 0.020 g total sugars g BSG-1 at 200 °C and 230 °C, respectively). Afterwards, the pH (5.0, 5.5 and 6.0) and organic loads (10, 20 and 30 gCOD L-1) effect on the acidogenic fermentation of hydrolyzed BSG was studied in batch. It was verified, regardless of the condition, that the most produced acids are acetic and butyric. As pH and organic load affects the fermentation products profile, it is possible to manipulate PHA composition. At last, the acidogenic fermentation of hydrolyzed BSG was studied in a continuous mode, using an expanded granular sludge bed reactor (EGSB). Due to the reduced operating time, it was not possible to reach stability. However, it was observed that sugars were consumed to produce organic acids. This revealed the potential of EGSB to be used for BSG acidogenic fermentation towards PHA production. |
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Acidogenic fermentation of brewer’s spent grain towards polyhydroxyalkanoates productionbrewer’s spent grainanaerobic granulesacidogenic fermentationorganic acidsmixed microbial culturesexpanded granular sludge bed reactorDomínio/Área Científica::Engenharia e Tecnologia::Engenharia QuímicaPolyhydroxyalkanoates (PHA) are fully biodegradable polyesters, synthesized by microorganisms from renewable resources, which reveal an alternative to petroleum-based plastics. Its production by mixed microbial cultures, unlike pure cultures, allows the use of industrial by-products in the absence of sterility conditions, potentially reducing process costs. The study described focused on the valorization of a waste from a brewery industry, brewer’s spent grain (BSG), through organic acids production, towards PHA production. PHA production using mixed microbial cultures involves three steps: (1) acidogenic fermentation of BSG for organic acids production, (2) selection of the mixed cultures able to accumulate PHA and (3) PHA production. In order to extract the sugars necessary to produce organic acids (phase 1), pre-treatment methods such as acid hydrolysis and subcritical water have been studied. Acid hydrolysis was selected for further experiments as the hydrolysis yield on sugars reached was higher than using subcritical water (0.152 g total sugars g BSG-1 versus 0.008 and 0.020 g total sugars g BSG-1 at 200 °C and 230 °C, respectively). Afterwards, the pH (5.0, 5.5 and 6.0) and organic loads (10, 20 and 30 gCOD L-1) effect on the acidogenic fermentation of hydrolyzed BSG was studied in batch. It was verified, regardless of the condition, that the most produced acids are acetic and butyric. As pH and organic load affects the fermentation products profile, it is possible to manipulate PHA composition. At last, the acidogenic fermentation of hydrolyzed BSG was studied in a continuous mode, using an expanded granular sludge bed reactor (EGSB). Due to the reduced operating time, it was not possible to reach stability. However, it was observed that sugars were consumed to produce organic acids. This revealed the potential of EGSB to be used for BSG acidogenic fermentation towards PHA production.Duque, AnoukRUNGuarda, Eliana da Costa2020-11-01T01:30:31Z2017-092017-112017-09-01T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisapplication/pdfhttp://hdl.handle.net/10362/25156enginfo:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2024-03-11T04:13:11Zoai:run.unl.pt:10362/25156Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-20T03:28:13.228945Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse |
dc.title.none.fl_str_mv |
Acidogenic fermentation of brewer’s spent grain towards polyhydroxyalkanoates production |
title |
Acidogenic fermentation of brewer’s spent grain towards polyhydroxyalkanoates production |
spellingShingle |
Acidogenic fermentation of brewer’s spent grain towards polyhydroxyalkanoates production Guarda, Eliana da Costa brewer’s spent grain anaerobic granules acidogenic fermentation organic acids mixed microbial cultures expanded granular sludge bed reactor Domínio/Área Científica::Engenharia e Tecnologia::Engenharia Química |
title_short |
Acidogenic fermentation of brewer’s spent grain towards polyhydroxyalkanoates production |
title_full |
Acidogenic fermentation of brewer’s spent grain towards polyhydroxyalkanoates production |
title_fullStr |
Acidogenic fermentation of brewer’s spent grain towards polyhydroxyalkanoates production |
title_full_unstemmed |
Acidogenic fermentation of brewer’s spent grain towards polyhydroxyalkanoates production |
title_sort |
Acidogenic fermentation of brewer’s spent grain towards polyhydroxyalkanoates production |
author |
Guarda, Eliana da Costa |
author_facet |
Guarda, Eliana da Costa |
author_role |
author |
dc.contributor.none.fl_str_mv |
Duque, Anouk RUN |
dc.contributor.author.fl_str_mv |
Guarda, Eliana da Costa |
dc.subject.por.fl_str_mv |
brewer’s spent grain anaerobic granules acidogenic fermentation organic acids mixed microbial cultures expanded granular sludge bed reactor Domínio/Área Científica::Engenharia e Tecnologia::Engenharia Química |
topic |
brewer’s spent grain anaerobic granules acidogenic fermentation organic acids mixed microbial cultures expanded granular sludge bed reactor Domínio/Área Científica::Engenharia e Tecnologia::Engenharia Química |
description |
Polyhydroxyalkanoates (PHA) are fully biodegradable polyesters, synthesized by microorganisms from renewable resources, which reveal an alternative to petroleum-based plastics. Its production by mixed microbial cultures, unlike pure cultures, allows the use of industrial by-products in the absence of sterility conditions, potentially reducing process costs. The study described focused on the valorization of a waste from a brewery industry, brewer’s spent grain (BSG), through organic acids production, towards PHA production. PHA production using mixed microbial cultures involves three steps: (1) acidogenic fermentation of BSG for organic acids production, (2) selection of the mixed cultures able to accumulate PHA and (3) PHA production. In order to extract the sugars necessary to produce organic acids (phase 1), pre-treatment methods such as acid hydrolysis and subcritical water have been studied. Acid hydrolysis was selected for further experiments as the hydrolysis yield on sugars reached was higher than using subcritical water (0.152 g total sugars g BSG-1 versus 0.008 and 0.020 g total sugars g BSG-1 at 200 °C and 230 °C, respectively). Afterwards, the pH (5.0, 5.5 and 6.0) and organic loads (10, 20 and 30 gCOD L-1) effect on the acidogenic fermentation of hydrolyzed BSG was studied in batch. It was verified, regardless of the condition, that the most produced acids are acetic and butyric. As pH and organic load affects the fermentation products profile, it is possible to manipulate PHA composition. At last, the acidogenic fermentation of hydrolyzed BSG was studied in a continuous mode, using an expanded granular sludge bed reactor (EGSB). Due to the reduced operating time, it was not possible to reach stability. However, it was observed that sugars were consumed to produce organic acids. This revealed the potential of EGSB to be used for BSG acidogenic fermentation towards PHA production. |
publishDate |
2017 |
dc.date.none.fl_str_mv |
2017-09 2017-11 2017-09-01T00:00:00Z 2020-11-01T01:30:31Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/masterThesis |
format |
masterThesis |
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publishedVersion |
dc.identifier.uri.fl_str_mv |
http://hdl.handle.net/10362/25156 |
url |
http://hdl.handle.net/10362/25156 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.source.none.fl_str_mv |
reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação instacron:RCAAP |
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Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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RCAAP |
institution |
RCAAP |
reponame_str |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
collection |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
repository.name.fl_str_mv |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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1799137908581466112 |