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Ufuk Gündüz - One of the best experts on this subject based on the ideXlab platform.
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Hydrogen production by hup^− mutant and wild-type strains of Rhodobacter capsulatus from dark Fermentation Effluent of sugar beet thick juice in batch and continuous photobioreactors
Bioprocess and Biosystems Engineering, 2015Co-Authors: Basar Uyar, Ebru Özgür, Meral Yücel, Ufuk Gündüz, Muazzez Gürgan, Inci ErogluAbstract:Photofermentative production of hydrogen is a promising and sustainable process; however, it should be coupled to dark Fermentation to become cost effective. In order to integrate dark Fermentation and photoFermentation, the suitability of dark fermenter Effluents for the photofermentative hydrogen production must be demonstrated. In this study, thermophilic dark fermenter Effluent (DFE) of sugar beet thick juice was used as a substrate in photoFermentation process to compare wild-type and uptake hydrogenase-deficient ( hup ^−) mutant strains of Rhodobacter capsulatus by means of hydrogen production and biomass growth. The tests were conducted in small-scale (50 mL) batch and large-scale (4 L) continuous photobioreactors in indoor conditions under continuous illumination. In small scale batch conditions, maximum cell concentrations were 0.92 gdcw/ L _c and 1.50 gdcw/ L _c, hydrogen yields were 34 % and 31 %, hydrogen productivities were 0.49 mmol/( L _c·h) and 0.26 mmol/(L_c·h), for hup ^− and wild-type cells, respectively. In large-scale continuous conditions, maximum cell concentrations were 1.44 gdcw/ L _c and 1.87 gdcw/ L _c, hydrogen yields were 48 and 46 %, and hydrogen productivities were 1.01 mmol/( L _c·h) and 1.05 mmol/( L _c·h), for hup ^− and wild-type cells, respectively. Our results showed that Rhodobacter capsulatus hup ^− cells reached to a lower maximum cell concentration but their hydrogen yield and productivity were in the same range or superior compared to the wild-type cells in both batch and continuous operating modes. The maximum biomass concentration, yield and productivity of hydrogen were higher in continuous mode compared to the batch mode with both bacterial strains.
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Photofermentative hydrogen production using dark Fermentation Effluent of sugar beet thick juice in outdoor conditions
International Journal of Hydrogen Energy, 2012Co-Authors: Endam Özkan, Basar Uyar, Ebru Özgür, Meral Yücel, Inci Eroglu, Ufuk GündüzAbstract:Abstract In the present study, photofermentative hydrogen production on thermophilic dark Fermentation Effluent (DFE) of sugar beet thick juice was investigated in a solar fed-batch panel photobioreactor (PBR) using Rhodobacter capsulatus YO3 (hup − ) during summer 2009 in Ankara, Turkey. The DFE was obtained by continuous dark Fermentation of sugar beet thick juice by extreme thermophile Caldicellulosiruptor saccharolyticus and it contains acetate (125 mM) and NH 4 + (7.7 mM) as the main carbon and nitrogen sources, respectively. The photoFermentation process was done in a 4 L plexiglas panel PBR which was daily fed at a rate of 10% of the PBR volume. The DFE was diluted 3 times to adjust the acetate concentration to approximately 40 mM and supplemented with potassium phosphate buffer, Fe and Mo. In order to control the temperature, cooling was provided by recirculating chilled water through a tubing inside the reactor. Hydrogen productivity of 1.12 mmol/L c /h and molar yield of 77% of theoretical maximum over consumed substrate were attained over 15 days of operation. The results indicated that Rb . capsulatus YO3 could effectively utilize the DFE of sugar beet thick juice for growth and hydrogen production, therefore facilitating the integration of the dark and photo-Fermentation processes for sustainable biohydrogen production.
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Biohydrogen production in an outdoor panel photobioreactor on dark Fermentation Effluent of molasses
International Journal of Hydrogen Energy, 2011Co-Authors: Sevler Gokce Avcioglu, Ebru Özgür, Meral Yücel, Inci Eroglu, Ufuk GündüzAbstract:Abstract Hydrogen is regarded as an ideal energy carrier if it is produced from renewable resources such as biomass. Sequential operation of dark and photoFermentation allows a highly efficient production of hydrogen from biomass, as maximal conversion of the energy in the carbohydrates to hydrogen can be achieved. In this study photofermentative hydrogen production was carried out in a solar panel photobioreactor by Rhodobacter capsulatus wild type (DSM 1710) and Rhodobacter capsulatus hup− (YO3) strain on the molasses dark Fermentation Effluents which were obtained using an extreme thermophile Caldicellusiruptor saccharolyticus in the dark Fermentation step. Continuous hydrogen production on the molasses dark Fermentation Effluents was achieved up to 55 days with R. capsulatus wild type and 75 days with R. capsulatus hup− in outdoor conditions during summer 2009, in Ankara Turkey. The maximum hydrogen yield obtained using R. capsulatus hup- was 78% (of the theoretical maximum) and the maximum hydrogen productivity was 0.67 mmol H2/Lc.h. The maximum hydrogen productivity and yield of the wild type strain on the molasses dark Fermentation Effluents were 0.50 mmol H2/Lc.h and 50%, respectively. The changes in climatic conditions, particularly daily global solar radiation, affected the hydrogen productivity and yield.
Largus T. Angenent - One of the best experts on this subject based on the ideXlab platform.
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Upgrading syngas Fermentation Effluent using Clostridium kluyveri in a continuous Fermentation
Biotechnology for Biofuels, 2017Co-Authors: Sylvia Gildemyn, Bastian Molitor, Joseph G. Usack, Mytien Nguyen, Korneel Rabaey, Largus T. AngenentAbstract:Background The product of current syngas Fermentation systems is an ethanol/acetic acid mixture and the goal is to maximize ethanol recovery. However, ethanol currently has a relatively low market value and its separation from the Fermentation broth is energy intensive. We can circumvent these disadvantages of ethanol production by converting the dilute ethanol/acetic acid mixture into products with longer carbon backbones, which are of higher value and are more easily extracted than ethanol. Chain elongation, which is the bioprocess in which ethanol is used to elongate short-chain carboxylic acids to medium-chain carboxylic acids (MCCAs), has been studied with pure cultures and open cultures of microbial consortia (microbiomes) with several different substrates. While upgrading syngas Fermentation Effluent has been studied with open cultures, to our knowledge, no study exists that has performed this with pure cultures. Results Here, pure cultures of Clostridium kluyveri were used in continuous bioreactors to convert ethanol/acetic acid mixtures into MCCAs. Besides changing the operating conditions in regards to substrate loading rates and composition, the effect of in-line product extraction, pH, and the use of real syngas Fermentation Effluent on production rates were tested. Increasing the organic loading rates resulted in proportionally higher production rates of n -caproic acid, which were up to 40 mM day^−1 (4.64 g L^−1 day^−1) at carbon conversion efficiencies of 90% or higher. The production rates were similar for bioreactors with and without in-line product extraction. Furthermore, a lower ethanol/acetic acid ratio (3:1 instead of 10:1) enabled faster and more efficient n -caproic acid production. In addition, n -caprylic acid production was observed for the first time with C. kluyveri (up to 2.19 ± 0.34 mM in batch). Finally, the use of real Effluent from syngas Fermentation, without added yeast extract, but with added defined growth factors, did maintain similar production rates. Throughout the operating period, we observed that the metabolism of C. kluyveri was inhibited at a mildly acidic pH value of 5.5 compared to a pH value of 7.0, while reactor microbiomes perform successfully at mildly acidic conditions. Conclusions Clostridium kluyveri can be used as a biocatalyst to upgrade syngas Fermentation Effluent into MCCAs at pH values above 5.5.
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Upgrading syngas Fermentation Effluent using Clostridium kluyveri in a continuous Fermentation
Biotechnology for biofuels, 2017Co-Authors: Sylvia Gildemyn, Bastian Molitor, Joseph G. Usack, Mytien Nguyen, Korneel Rabaey, Largus T. AngenentAbstract:Background The product of current syngas Fermentation systems is an ethanol/acetic acid mixture and the goal is to maximize ethanol recovery. However, ethanol currently has a relatively low market value and its separation from the Fermentation broth is energy intensive. We can circumvent these disadvantages of ethanol production by converting the dilute ethanol/acetic acid mixture into products with longer carbon backbones, which are of higher value and are more easily extracted than ethanol. Chain elongation, which is the bioprocess in which ethanol is used to elongate short-chain carboxylic acids to medium-chain carboxylic acids (MCCAs), has been studied with pure cultures and open cultures of microbial consortia (microbiomes) with several different substrates. While upgrading syngas Fermentation Effluent has been studied with open cultures, to our knowledge, no study exists that has performed this with pure cultures.
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Upgrading dilute ethanol from syngas Fermentation to n-caproate with reactor microbiomes.
Bioresource technology, 2013Co-Authors: Divya Vasudevan, Hanno Richter, Largus T. AngenentAbstract:Abstract Fermentation of syngas from renewable biomass, which is part of the syngas platform, is gaining momentum. Here, the objective was to evaluate a proof-of-concept bioprocessing system with diluted ethanol and acetic acid in actual syngas Fermentation Effluent as the substrate for chain elongation into the product n- caproic acid, which can be separated with less energy input than ethanol. Chain elongation is performed with open cultures of microbial populations (reactor microbiomes) as part of the carboxylate platform. The highest concentration of n -caproic acid of ∼1 g L −1 was produced at a pH of 5.44 and a production rate of 1.7 g L −1 day −1 . A higher n -butyrate production rate of 20 g L −1 day −1 indicated that product toxicity was limiting the chain elongation step from n -butyric acid to n -caproic acid. This result shows that the syngas and carboxylate platforms can be integrated within a biorefinery, but that product separation is necessary.
Inci Eroglu - One of the best experts on this subject based on the ideXlab platform.
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Hydrogen production by hup^− mutant and wild-type strains of Rhodobacter capsulatus from dark Fermentation Effluent of sugar beet thick juice in batch and continuous photobioreactors
Bioprocess and Biosystems Engineering, 2015Co-Authors: Basar Uyar, Ebru Özgür, Meral Yücel, Ufuk Gündüz, Muazzez Gürgan, Inci ErogluAbstract:Photofermentative production of hydrogen is a promising and sustainable process; however, it should be coupled to dark Fermentation to become cost effective. In order to integrate dark Fermentation and photoFermentation, the suitability of dark fermenter Effluents for the photofermentative hydrogen production must be demonstrated. In this study, thermophilic dark fermenter Effluent (DFE) of sugar beet thick juice was used as a substrate in photoFermentation process to compare wild-type and uptake hydrogenase-deficient ( hup ^−) mutant strains of Rhodobacter capsulatus by means of hydrogen production and biomass growth. The tests were conducted in small-scale (50 mL) batch and large-scale (4 L) continuous photobioreactors in indoor conditions under continuous illumination. In small scale batch conditions, maximum cell concentrations were 0.92 gdcw/ L _c and 1.50 gdcw/ L _c, hydrogen yields were 34 % and 31 %, hydrogen productivities were 0.49 mmol/( L _c·h) and 0.26 mmol/(L_c·h), for hup ^− and wild-type cells, respectively. In large-scale continuous conditions, maximum cell concentrations were 1.44 gdcw/ L _c and 1.87 gdcw/ L _c, hydrogen yields were 48 and 46 %, and hydrogen productivities were 1.01 mmol/( L _c·h) and 1.05 mmol/( L _c·h), for hup ^− and wild-type cells, respectively. Our results showed that Rhodobacter capsulatus hup ^− cells reached to a lower maximum cell concentration but their hydrogen yield and productivity were in the same range or superior compared to the wild-type cells in both batch and continuous operating modes. The maximum biomass concentration, yield and productivity of hydrogen were higher in continuous mode compared to the batch mode with both bacterial strains.
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Photofermentative hydrogen production using dark Fermentation Effluent of sugar beet thick juice in outdoor conditions
International Journal of Hydrogen Energy, 2012Co-Authors: Endam Özkan, Basar Uyar, Ebru Özgür, Meral Yücel, Inci Eroglu, Ufuk GündüzAbstract:Abstract In the present study, photofermentative hydrogen production on thermophilic dark Fermentation Effluent (DFE) of sugar beet thick juice was investigated in a solar fed-batch panel photobioreactor (PBR) using Rhodobacter capsulatus YO3 (hup − ) during summer 2009 in Ankara, Turkey. The DFE was obtained by continuous dark Fermentation of sugar beet thick juice by extreme thermophile Caldicellulosiruptor saccharolyticus and it contains acetate (125 mM) and NH 4 + (7.7 mM) as the main carbon and nitrogen sources, respectively. The photoFermentation process was done in a 4 L plexiglas panel PBR which was daily fed at a rate of 10% of the PBR volume. The DFE was diluted 3 times to adjust the acetate concentration to approximately 40 mM and supplemented with potassium phosphate buffer, Fe and Mo. In order to control the temperature, cooling was provided by recirculating chilled water through a tubing inside the reactor. Hydrogen productivity of 1.12 mmol/L c /h and molar yield of 77% of theoretical maximum over consumed substrate were attained over 15 days of operation. The results indicated that Rb . capsulatus YO3 could effectively utilize the DFE of sugar beet thick juice for growth and hydrogen production, therefore facilitating the integration of the dark and photo-Fermentation processes for sustainable biohydrogen production.
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Biohydrogen production in an outdoor panel photobioreactor on dark Fermentation Effluent of molasses
International Journal of Hydrogen Energy, 2011Co-Authors: Sevler Gokce Avcioglu, Ebru Özgür, Meral Yücel, Inci Eroglu, Ufuk GündüzAbstract:Abstract Hydrogen is regarded as an ideal energy carrier if it is produced from renewable resources such as biomass. Sequential operation of dark and photoFermentation allows a highly efficient production of hydrogen from biomass, as maximal conversion of the energy in the carbohydrates to hydrogen can be achieved. In this study photofermentative hydrogen production was carried out in a solar panel photobioreactor by Rhodobacter capsulatus wild type (DSM 1710) and Rhodobacter capsulatus hup− (YO3) strain on the molasses dark Fermentation Effluents which were obtained using an extreme thermophile Caldicellusiruptor saccharolyticus in the dark Fermentation step. Continuous hydrogen production on the molasses dark Fermentation Effluents was achieved up to 55 days with R. capsulatus wild type and 75 days with R. capsulatus hup− in outdoor conditions during summer 2009, in Ankara Turkey. The maximum hydrogen yield obtained using R. capsulatus hup- was 78% (of the theoretical maximum) and the maximum hydrogen productivity was 0.67 mmol H2/Lc.h. The maximum hydrogen productivity and yield of the wild type strain on the molasses dark Fermentation Effluents were 0.50 mmol H2/Lc.h and 50%, respectively. The changes in climatic conditions, particularly daily global solar radiation, affected the hydrogen productivity and yield.
Basar Uyar - One of the best experts on this subject based on the ideXlab platform.
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Hydrogen production by hup^− mutant and wild-type strains of Rhodobacter capsulatus from dark Fermentation Effluent of sugar beet thick juice in batch and continuous photobioreactors
Bioprocess and Biosystems Engineering, 2015Co-Authors: Basar Uyar, Ebru Özgür, Meral Yücel, Ufuk Gündüz, Muazzez Gürgan, Inci ErogluAbstract:Photofermentative production of hydrogen is a promising and sustainable process; however, it should be coupled to dark Fermentation to become cost effective. In order to integrate dark Fermentation and photoFermentation, the suitability of dark fermenter Effluents for the photofermentative hydrogen production must be demonstrated. In this study, thermophilic dark fermenter Effluent (DFE) of sugar beet thick juice was used as a substrate in photoFermentation process to compare wild-type and uptake hydrogenase-deficient ( hup ^−) mutant strains of Rhodobacter capsulatus by means of hydrogen production and biomass growth. The tests were conducted in small-scale (50 mL) batch and large-scale (4 L) continuous photobioreactors in indoor conditions under continuous illumination. In small scale batch conditions, maximum cell concentrations were 0.92 gdcw/ L _c and 1.50 gdcw/ L _c, hydrogen yields were 34 % and 31 %, hydrogen productivities were 0.49 mmol/( L _c·h) and 0.26 mmol/(L_c·h), for hup ^− and wild-type cells, respectively. In large-scale continuous conditions, maximum cell concentrations were 1.44 gdcw/ L _c and 1.87 gdcw/ L _c, hydrogen yields were 48 and 46 %, and hydrogen productivities were 1.01 mmol/( L _c·h) and 1.05 mmol/( L _c·h), for hup ^− and wild-type cells, respectively. Our results showed that Rhodobacter capsulatus hup ^− cells reached to a lower maximum cell concentration but their hydrogen yield and productivity were in the same range or superior compared to the wild-type cells in both batch and continuous operating modes. The maximum biomass concentration, yield and productivity of hydrogen were higher in continuous mode compared to the batch mode with both bacterial strains.
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Photofermentative hydrogen production using dark Fermentation Effluent of sugar beet thick juice in outdoor conditions
International Journal of Hydrogen Energy, 2012Co-Authors: Endam Özkan, Basar Uyar, Ebru Özgür, Meral Yücel, Inci Eroglu, Ufuk GündüzAbstract:Abstract In the present study, photofermentative hydrogen production on thermophilic dark Fermentation Effluent (DFE) of sugar beet thick juice was investigated in a solar fed-batch panel photobioreactor (PBR) using Rhodobacter capsulatus YO3 (hup − ) during summer 2009 in Ankara, Turkey. The DFE was obtained by continuous dark Fermentation of sugar beet thick juice by extreme thermophile Caldicellulosiruptor saccharolyticus and it contains acetate (125 mM) and NH 4 + (7.7 mM) as the main carbon and nitrogen sources, respectively. The photoFermentation process was done in a 4 L plexiglas panel PBR which was daily fed at a rate of 10% of the PBR volume. The DFE was diluted 3 times to adjust the acetate concentration to approximately 40 mM and supplemented with potassium phosphate buffer, Fe and Mo. In order to control the temperature, cooling was provided by recirculating chilled water through a tubing inside the reactor. Hydrogen productivity of 1.12 mmol/L c /h and molar yield of 77% of theoretical maximum over consumed substrate were attained over 15 days of operation. The results indicated that Rb . capsulatus YO3 could effectively utilize the DFE of sugar beet thick juice for growth and hydrogen production, therefore facilitating the integration of the dark and photo-Fermentation processes for sustainable biohydrogen production.
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photoproduction of hydrogen by rhodobacter capsulatus from thermophilic Fermentation Effluent
Bioprocess and Biosystems Engineering, 2009Co-Authors: Basar Uyar, Jerzy Gebicki, M. Schumacher, Michael ModigellAbstract:Rhodobacter capsulatus was used for the phototrophic hydrogen production on Effluent solution derived from the thermophilic Fermentation of Miscanthus hydrolysate by Thermotoga neapolitana. Pretreatments such as centrifugation, dilution, buffer addition, pH adjustment and sterilization were suggested for the Effluent before being fed to the photoFermentation. Batch-wise experiments showed that R. capsulatus grows and produces hydrogen on the pretreated Effluent solution. Moreover, it was found that the hydrogen yield increased from 0.3 to 1.0 L/Lculture by addition of iron to the Effluent solution.
Ebru Özgür - One of the best experts on this subject based on the ideXlab platform.
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Hydrogen production by hup^− mutant and wild-type strains of Rhodobacter capsulatus from dark Fermentation Effluent of sugar beet thick juice in batch and continuous photobioreactors
Bioprocess and Biosystems Engineering, 2015Co-Authors: Basar Uyar, Ebru Özgür, Meral Yücel, Ufuk Gündüz, Muazzez Gürgan, Inci ErogluAbstract:Photofermentative production of hydrogen is a promising and sustainable process; however, it should be coupled to dark Fermentation to become cost effective. In order to integrate dark Fermentation and photoFermentation, the suitability of dark fermenter Effluents for the photofermentative hydrogen production must be demonstrated. In this study, thermophilic dark fermenter Effluent (DFE) of sugar beet thick juice was used as a substrate in photoFermentation process to compare wild-type and uptake hydrogenase-deficient ( hup ^−) mutant strains of Rhodobacter capsulatus by means of hydrogen production and biomass growth. The tests were conducted in small-scale (50 mL) batch and large-scale (4 L) continuous photobioreactors in indoor conditions under continuous illumination. In small scale batch conditions, maximum cell concentrations were 0.92 gdcw/ L _c and 1.50 gdcw/ L _c, hydrogen yields were 34 % and 31 %, hydrogen productivities were 0.49 mmol/( L _c·h) and 0.26 mmol/(L_c·h), for hup ^− and wild-type cells, respectively. In large-scale continuous conditions, maximum cell concentrations were 1.44 gdcw/ L _c and 1.87 gdcw/ L _c, hydrogen yields were 48 and 46 %, and hydrogen productivities were 1.01 mmol/( L _c·h) and 1.05 mmol/( L _c·h), for hup ^− and wild-type cells, respectively. Our results showed that Rhodobacter capsulatus hup ^− cells reached to a lower maximum cell concentration but their hydrogen yield and productivity were in the same range or superior compared to the wild-type cells in both batch and continuous operating modes. The maximum biomass concentration, yield and productivity of hydrogen were higher in continuous mode compared to the batch mode with both bacterial strains.
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Photofermentative hydrogen production using dark Fermentation Effluent of sugar beet thick juice in outdoor conditions
International Journal of Hydrogen Energy, 2012Co-Authors: Endam Özkan, Basar Uyar, Ebru Özgür, Meral Yücel, Inci Eroglu, Ufuk GündüzAbstract:Abstract In the present study, photofermentative hydrogen production on thermophilic dark Fermentation Effluent (DFE) of sugar beet thick juice was investigated in a solar fed-batch panel photobioreactor (PBR) using Rhodobacter capsulatus YO3 (hup − ) during summer 2009 in Ankara, Turkey. The DFE was obtained by continuous dark Fermentation of sugar beet thick juice by extreme thermophile Caldicellulosiruptor saccharolyticus and it contains acetate (125 mM) and NH 4 + (7.7 mM) as the main carbon and nitrogen sources, respectively. The photoFermentation process was done in a 4 L plexiglas panel PBR which was daily fed at a rate of 10% of the PBR volume. The DFE was diluted 3 times to adjust the acetate concentration to approximately 40 mM and supplemented with potassium phosphate buffer, Fe and Mo. In order to control the temperature, cooling was provided by recirculating chilled water through a tubing inside the reactor. Hydrogen productivity of 1.12 mmol/L c /h and molar yield of 77% of theoretical maximum over consumed substrate were attained over 15 days of operation. The results indicated that Rb . capsulatus YO3 could effectively utilize the DFE of sugar beet thick juice for growth and hydrogen production, therefore facilitating the integration of the dark and photo-Fermentation processes for sustainable biohydrogen production.
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Biohydrogen production in an outdoor panel photobioreactor on dark Fermentation Effluent of molasses
International Journal of Hydrogen Energy, 2011Co-Authors: Sevler Gokce Avcioglu, Ebru Özgür, Meral Yücel, Inci Eroglu, Ufuk GündüzAbstract:Abstract Hydrogen is regarded as an ideal energy carrier if it is produced from renewable resources such as biomass. Sequential operation of dark and photoFermentation allows a highly efficient production of hydrogen from biomass, as maximal conversion of the energy in the carbohydrates to hydrogen can be achieved. In this study photofermentative hydrogen production was carried out in a solar panel photobioreactor by Rhodobacter capsulatus wild type (DSM 1710) and Rhodobacter capsulatus hup− (YO3) strain on the molasses dark Fermentation Effluents which were obtained using an extreme thermophile Caldicellusiruptor saccharolyticus in the dark Fermentation step. Continuous hydrogen production on the molasses dark Fermentation Effluents was achieved up to 55 days with R. capsulatus wild type and 75 days with R. capsulatus hup− in outdoor conditions during summer 2009, in Ankara Turkey. The maximum hydrogen yield obtained using R. capsulatus hup- was 78% (of the theoretical maximum) and the maximum hydrogen productivity was 0.67 mmol H2/Lc.h. The maximum hydrogen productivity and yield of the wild type strain on the molasses dark Fermentation Effluents were 0.50 mmol H2/Lc.h and 50%, respectively. The changes in climatic conditions, particularly daily global solar radiation, affected the hydrogen productivity and yield.