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In Seop Chang - One of the best experts on this subject based on the ideXlab platform.
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methanol supply speeds up synthesis gas fermentation by methylotrophic acetogenic bacterium Eubacterium limosum kist612
Bioresource Technology, 2021Co-Authors: Jiyeon Kim, Jiyeong Jeong, Nulee Jang, Sehoon Park, Mungyu Lee, Byeongchan Kang, Se Hwan Jang, Jinsung Jeon, Zeeyong Park, In Seop ChangAbstract:This study analyzed the effect of methanol on the metabolism of syngas components (i.e., H2 and CO) by the syngas fermenting acetogenic strain E. limosum KIST612. The culture characteristics and relevant proteomic expressions (as fold changes) were carefully analyzed under CO/CO2 and H2/CO2 conditions with and without methanol addition, as well as, under methanol/CO2 conditions. The culture characteristics (specific growth rate and H2 consumption rate) under H2/CO2 conditions were greatly enhanced in the presence of methanol, by 4.0 and 2.7 times, respectively. However, the promoting effect of methanol was not significant under CO/CO2 conditions. Proteomic fold changes in most enzyme expression levels in the Wood-Ljungdahl pathway and chemiosmotic energy conservation also exhibited high correspondence between methanol and H2/CO2 but not between methanol and CO/CO2. These findings suggest the advantages of methanol addition to H2/CO2 for biomass enhancement and faster consumption of gaseous substrates during syngas fermentation.
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genetic engineering system for syngas utilizing acetogen Eubacterium limosum kist612
Bioresource Technology Reports, 2020Co-Authors: Jiyeong Jeong, In-geol Choi, Jiyeon Kim, Byeonghyeok Park, In Seop ChangAbstract:Abstract Acetogens are capable of fixing inorganic gases to organic acids with/without bio-alcohols via the Wood-Ljungdahl pathway. Because of their potential to produce value-added metabolites, acetogens have received attention in the field of biorefinery. Eubacterium limosum KIST612 is one of the promising acetogens, which has been well studied for its syngas utilizing ability, and its genomic data are available. A strain-specific genetic engineering system for maximal benefits has not yet been studied in the strain, though. In the present study, we first developed a foreign gene expression system using a native constitutive promoter and the CRISPR/Cas9-based gene editing system for KIST612. Transcriptomics-based candidate selection of native promoter and GUS reporter gene assay enabled the identification of promoter of rubredoxin oxidoreductase (Prbo) as a strong constitutive promoter in the strain. Application of Cas9-mediated genome editing was able to effectively delete the pyrF gene in the chromosome of KIST612.
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acetate assisted increase of butyrate production by Eubacterium limosum kist612 during carbon monoxide fermentation
Bioresource Technology, 2017Co-Authors: Shinyoung Park, Jiyeong Jeong, In-geol Choi, Muhammad Yasin, Minseok Cha, Hyunsoo Kang, Nulee Jang, In Seop ChangAbstract:The acetate-assisted cultivation of Eubacterium limosum KIST612 was found to provide a way for enhancing cell mass, the carbon monoxide (CO) consumption rate, and butyrate production using CO as an electron and energy source. Cell growth (146%), μmax (121%), and CO consumption rates (151%) increased significantly upon the addition of 30mM acetate to microbial cultures. The main product of CO fermentation by E. limosum KIST612 shifted from acetate to butyrate in the presence of acetate, and 5.72mM butyrate was produced at the end of the reaction. The resting cell experimental conditions indicated acetate uptake and an increase in the butyrate concentration. Three routes to acetate assimilation and energy conservation were suggested based on given experimental results and previously genome sequencing data. Acetate assimilation via propionate CoA-transferase (PCT) was expected to produce 1.5mol ATP/mol butyrate, and was thus anticipated to be the most preferred route.
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Energy Conservation Model Based on Genomic and Experimental Analyses of a Carbon Monoxide-Utilizing, Butyrate-Forming Acetogen, Eubacterium limosum KIST612
Applied and Environmental Microbiology, 2015Co-Authors: Jiyeong Jeong, Johannes Bertsch, Verena Hess, Sunju Choi, In-geol Choi, In Seop Chang, Volker MullerAbstract:Eubacterium limosum KIST612 is one of the few acetogens that can produce butyrate from carbon monoxide. We have used a genome-guided analysis to delineate the path of butyrate formation, the enzymes involved, and the potential coupling to ATP synthesis. Oxidation of CO is catalyzed by the acetyl-coenzyme A (CoA) synthase/CO dehydrogenase and coupled to the reduction of ferredoxin. Oxidation of reduced ferredoxin is catalyzed by the Rnf complex and Na+ dependent. Consistent with the finding of a Na+-dependent Rnf complex is the presence of a conserved Na+-binding motif in the c subunit of the ATP synthase. Butyrate formation is from acetyl-CoA via acetoacetyl-CoA, hydroxybutyryl-CoA, crotonyl-CoA, and butyryl-CoA and is consistent with the finding of a gene cluster that encodes the enzymes for this pathway. The activity of the butyryl-CoA dehydrogenase was demonstrated. Reduction of crotonyl-CoA to butyryl-CoA with NADH as the reductant was coupled to reduction of ferredoxin. We postulate that the butyryl-CoA dehydrogenase uses flavin-based electron bifurcation to reduce ferredoxin, which is consistent with the finding of etfA and etfB genes next to it. The overall ATP yield was calculated and is significantly higher than the one obtained with H2 + CO2. The energetic benefit may be one reason that butyrate is formed only from CO but not from H2 + CO2.
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effect of internal pressure and gas liquid interface area on the co mass transfer coefficient using hollow fibre membranes as a high mass transfer gas diffusing system for microbial syngas fermentation
Bioresource Technology, 2014Co-Authors: Muhammad Yasin, Shinyoung Park, Yeseul Jeong, In Seop ChangAbstract:Abstract This study proposed a submerged hollow fibre membrane bioreactor (HFMBR) system capable of achieving high carbon monoxide (CO) mass transfer for applications in microbial synthesis gas conversion systems. Hydrophobic polyvinylidene fluoride (PVDF) membrane fibres were used to fabricate a membrane module, which was used for pressurising CO in water phase. Pressure through the hollow fibre lumen ( P ) and membrane surface area per unit working volume of the liquid ( A S / V L ) were used as controllable parameters to determine gas–liquid volumetric mass transfer coefficient ( k L a ) values. We found a k L a of 135.72 h −1 when P was 93.76 kPa and A S / V L was fixed at 27.5 m −1 . A higher k L a of 155.16 h −1 was achieved by increasing A S / V L to 62.5 m −1 at a lower P of 37.23 kPa. Practicality of HFMBR to support microbial growth and organic product formation was assessed by CO/CO 2 fermentation using Eubacterium limosum KIST612.
Shinyoung Park - One of the best experts on this subject based on the ideXlab platform.
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acetate assisted increase of butyrate production by Eubacterium limosum kist612 during carbon monoxide fermentation
Bioresource Technology, 2017Co-Authors: Shinyoung Park, Jiyeong Jeong, In-geol Choi, Muhammad Yasin, Minseok Cha, Hyunsoo Kang, Nulee Jang, In Seop ChangAbstract:The acetate-assisted cultivation of Eubacterium limosum KIST612 was found to provide a way for enhancing cell mass, the carbon monoxide (CO) consumption rate, and butyrate production using CO as an electron and energy source. Cell growth (146%), μmax (121%), and CO consumption rates (151%) increased significantly upon the addition of 30mM acetate to microbial cultures. The main product of CO fermentation by E. limosum KIST612 shifted from acetate to butyrate in the presence of acetate, and 5.72mM butyrate was produced at the end of the reaction. The resting cell experimental conditions indicated acetate uptake and an increase in the butyrate concentration. Three routes to acetate assimilation and energy conservation were suggested based on given experimental results and previously genome sequencing data. Acetate assimilation via propionate CoA-transferase (PCT) was expected to produce 1.5mol ATP/mol butyrate, and was thus anticipated to be the most preferred route.
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effect of internal pressure and gas liquid interface area on the co mass transfer coefficient using hollow fibre membranes as a high mass transfer gas diffusing system for microbial syngas fermentation
Bioresource Technology, 2014Co-Authors: Muhammad Yasin, Shinyoung Park, Yeseul Jeong, In Seop ChangAbstract:Abstract This study proposed a submerged hollow fibre membrane bioreactor (HFMBR) system capable of achieving high carbon monoxide (CO) mass transfer for applications in microbial synthesis gas conversion systems. Hydrophobic polyvinylidene fluoride (PVDF) membrane fibres were used to fabricate a membrane module, which was used for pressurising CO in water phase. Pressure through the hollow fibre lumen ( P ) and membrane surface area per unit working volume of the liquid ( A S / V L ) were used as controllable parameters to determine gas–liquid volumetric mass transfer coefficient ( k L a ) values. We found a k L a of 135.72 h −1 when P was 93.76 kPa and A S / V L was fixed at 27.5 m −1 . A higher k L a of 155.16 h −1 was achieved by increasing A S / V L to 62.5 m −1 at a lower P of 37.23 kPa. Practicality of HFMBR to support microbial growth and organic product formation was assessed by CO/CO 2 fermentation using Eubacterium limosum KIST612.
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effect of internal pressure and gas liquid interface area on the co mass transfer coefficient using hollow fibre membranes as a high mass transfer gas diffusing system for microbial syngas fermentation
Bioresource Technology, 2014Co-Authors: Muhammad Yasin, Shinyoung Park, Yeseul Jeong, Eun Yeol Lee, Jinwon Lee, In Seop ChangAbstract:Abstract This study proposed a submerged hollow fibre membrane bioreactor (HFMBR) system capable of achieving high carbon monoxide (CO) mass transfer for applications in microbial synthesis gas conversion systems. Hydrophobic polyvinylidene fluoride (PVDF) membrane fibres were used to fabricate a membrane module, which was used for pressurising CO in water phase. Pressure through the hollow fibre lumen ( P ) and membrane surface area per unit working volume of the liquid ( A S / V L ) were used as controllable parameters to determine gas–liquid volumetric mass transfer coefficient ( k L a ) values. We found a k L a of 135.72 h −1 when P was 93.76 kPa and A S / V L was fixed at 27.5 m −1 . A higher k L a of 155.16 h −1 was achieved by increasing A S / V L to 62.5 m −1 at a lower P of 37.23 kPa. Practicality of HFMBR to support microbial growth and organic product formation was assessed by CO/CO 2 fermentation using Eubacterium limosum KIST612.
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Complete Genome Sequence of a Carbon Monoxide-Utilizing Acetogen, Eubacterium limosum KIST612
Journal of Bacteriology, 2010Co-Authors: Hanseong Roh, Shinyoung Park, In Seop Chang, Daehee Kim, Dong Geon Choi, Su Jin Kim, In-geol ChoiAbstract:Eubacterium limosum KIST612 is an anaerobic acetogenic bacterium that uses CO as the sole carbon/energy source and produces acetate, butyrate, and ethanol. To evaluate its potential as a syngas microbial catalyst, we have sequenced the complete 4.3-Mb genome of E. limosum KIST612.
In-geol Choi - One of the best experts on this subject based on the ideXlab platform.
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genetic engineering system for syngas utilizing acetogen Eubacterium limosum kist612
Bioresource Technology Reports, 2020Co-Authors: Jiyeong Jeong, In-geol Choi, Jiyeon Kim, Byeonghyeok Park, In Seop ChangAbstract:Abstract Acetogens are capable of fixing inorganic gases to organic acids with/without bio-alcohols via the Wood-Ljungdahl pathway. Because of their potential to produce value-added metabolites, acetogens have received attention in the field of biorefinery. Eubacterium limosum KIST612 is one of the promising acetogens, which has been well studied for its syngas utilizing ability, and its genomic data are available. A strain-specific genetic engineering system for maximal benefits has not yet been studied in the strain, though. In the present study, we first developed a foreign gene expression system using a native constitutive promoter and the CRISPR/Cas9-based gene editing system for KIST612. Transcriptomics-based candidate selection of native promoter and GUS reporter gene assay enabled the identification of promoter of rubredoxin oxidoreductase (Prbo) as a strong constitutive promoter in the strain. Application of Cas9-mediated genome editing was able to effectively delete the pyrF gene in the chromosome of KIST612.
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acetate assisted increase of butyrate production by Eubacterium limosum kist612 during carbon monoxide fermentation
Bioresource Technology, 2017Co-Authors: Shinyoung Park, Jiyeong Jeong, In-geol Choi, Muhammad Yasin, Minseok Cha, Hyunsoo Kang, Nulee Jang, In Seop ChangAbstract:The acetate-assisted cultivation of Eubacterium limosum KIST612 was found to provide a way for enhancing cell mass, the carbon monoxide (CO) consumption rate, and butyrate production using CO as an electron and energy source. Cell growth (146%), μmax (121%), and CO consumption rates (151%) increased significantly upon the addition of 30mM acetate to microbial cultures. The main product of CO fermentation by E. limosum KIST612 shifted from acetate to butyrate in the presence of acetate, and 5.72mM butyrate was produced at the end of the reaction. The resting cell experimental conditions indicated acetate uptake and an increase in the butyrate concentration. Three routes to acetate assimilation and energy conservation were suggested based on given experimental results and previously genome sequencing data. Acetate assimilation via propionate CoA-transferase (PCT) was expected to produce 1.5mol ATP/mol butyrate, and was thus anticipated to be the most preferred route.
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Energy Conservation Model Based on Genomic and Experimental Analyses of a Carbon Monoxide-Utilizing, Butyrate-Forming Acetogen, Eubacterium limosum KIST612
Applied and Environmental Microbiology, 2015Co-Authors: Jiyeong Jeong, Johannes Bertsch, Verena Hess, Sunju Choi, In-geol Choi, In Seop Chang, Volker MullerAbstract:Eubacterium limosum KIST612 is one of the few acetogens that can produce butyrate from carbon monoxide. We have used a genome-guided analysis to delineate the path of butyrate formation, the enzymes involved, and the potential coupling to ATP synthesis. Oxidation of CO is catalyzed by the acetyl-coenzyme A (CoA) synthase/CO dehydrogenase and coupled to the reduction of ferredoxin. Oxidation of reduced ferredoxin is catalyzed by the Rnf complex and Na+ dependent. Consistent with the finding of a Na+-dependent Rnf complex is the presence of a conserved Na+-binding motif in the c subunit of the ATP synthase. Butyrate formation is from acetyl-CoA via acetoacetyl-CoA, hydroxybutyryl-CoA, crotonyl-CoA, and butyryl-CoA and is consistent with the finding of a gene cluster that encodes the enzymes for this pathway. The activity of the butyryl-CoA dehydrogenase was demonstrated. Reduction of crotonyl-CoA to butyryl-CoA with NADH as the reductant was coupled to reduction of ferredoxin. We postulate that the butyryl-CoA dehydrogenase uses flavin-based electron bifurcation to reduce ferredoxin, which is consistent with the finding of etfA and etfB genes next to it. The overall ATP yield was calculated and is significantly higher than the one obtained with H2 + CO2. The energetic benefit may be one reason that butyrate is formed only from CO but not from H2 + CO2.
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Complete Genome Sequence of a Carbon Monoxide-Utilizing Acetogen, Eubacterium limosum KIST612
Journal of Bacteriology, 2010Co-Authors: Hanseong Roh, Shinyoung Park, In Seop Chang, Daehee Kim, Dong Geon Choi, Su Jin Kim, In-geol ChoiAbstract:Eubacterium limosum KIST612 is an anaerobic acetogenic bacterium that uses CO as the sole carbon/energy source and produces acetate, butyrate, and ethanol. To evaluate its potential as a syngas microbial catalyst, we have sequenced the complete 4.3-Mb genome of E. limosum KIST612.
Muhammad Yasin - One of the best experts on this subject based on the ideXlab platform.
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acetate assisted increase of butyrate production by Eubacterium limosum kist612 during carbon monoxide fermentation
Bioresource Technology, 2017Co-Authors: Shinyoung Park, Jiyeong Jeong, In-geol Choi, Muhammad Yasin, Minseok Cha, Hyunsoo Kang, Nulee Jang, In Seop ChangAbstract:The acetate-assisted cultivation of Eubacterium limosum KIST612 was found to provide a way for enhancing cell mass, the carbon monoxide (CO) consumption rate, and butyrate production using CO as an electron and energy source. Cell growth (146%), μmax (121%), and CO consumption rates (151%) increased significantly upon the addition of 30mM acetate to microbial cultures. The main product of CO fermentation by E. limosum KIST612 shifted from acetate to butyrate in the presence of acetate, and 5.72mM butyrate was produced at the end of the reaction. The resting cell experimental conditions indicated acetate uptake and an increase in the butyrate concentration. Three routes to acetate assimilation and energy conservation were suggested based on given experimental results and previously genome sequencing data. Acetate assimilation via propionate CoA-transferase (PCT) was expected to produce 1.5mol ATP/mol butyrate, and was thus anticipated to be the most preferred route.
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effect of internal pressure and gas liquid interface area on the co mass transfer coefficient using hollow fibre membranes as a high mass transfer gas diffusing system for microbial syngas fermentation
Bioresource Technology, 2014Co-Authors: Muhammad Yasin, Shinyoung Park, Yeseul Jeong, In Seop ChangAbstract:Abstract This study proposed a submerged hollow fibre membrane bioreactor (HFMBR) system capable of achieving high carbon monoxide (CO) mass transfer for applications in microbial synthesis gas conversion systems. Hydrophobic polyvinylidene fluoride (PVDF) membrane fibres were used to fabricate a membrane module, which was used for pressurising CO in water phase. Pressure through the hollow fibre lumen ( P ) and membrane surface area per unit working volume of the liquid ( A S / V L ) were used as controllable parameters to determine gas–liquid volumetric mass transfer coefficient ( k L a ) values. We found a k L a of 135.72 h −1 when P was 93.76 kPa and A S / V L was fixed at 27.5 m −1 . A higher k L a of 155.16 h −1 was achieved by increasing A S / V L to 62.5 m −1 at a lower P of 37.23 kPa. Practicality of HFMBR to support microbial growth and organic product formation was assessed by CO/CO 2 fermentation using Eubacterium limosum KIST612.
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effect of internal pressure and gas liquid interface area on the co mass transfer coefficient using hollow fibre membranes as a high mass transfer gas diffusing system for microbial syngas fermentation
Bioresource Technology, 2014Co-Authors: Muhammad Yasin, Shinyoung Park, Yeseul Jeong, Eun Yeol Lee, Jinwon Lee, In Seop ChangAbstract:Abstract This study proposed a submerged hollow fibre membrane bioreactor (HFMBR) system capable of achieving high carbon monoxide (CO) mass transfer for applications in microbial synthesis gas conversion systems. Hydrophobic polyvinylidene fluoride (PVDF) membrane fibres were used to fabricate a membrane module, which was used for pressurising CO in water phase. Pressure through the hollow fibre lumen ( P ) and membrane surface area per unit working volume of the liquid ( A S / V L ) were used as controllable parameters to determine gas–liquid volumetric mass transfer coefficient ( k L a ) values. We found a k L a of 135.72 h −1 when P was 93.76 kPa and A S / V L was fixed at 27.5 m −1 . A higher k L a of 155.16 h −1 was achieved by increasing A S / V L to 62.5 m −1 at a lower P of 37.23 kPa. Practicality of HFMBR to support microbial growth and organic product formation was assessed by CO/CO 2 fermentation using Eubacterium limosum KIST612.
Volker Muller - One of the best experts on this subject based on the ideXlab platform.
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butyrate production in the acetogen Eubacterium limosum is dependent on the carbon and energy source
Microbial Biotechnology, 2021Co-Authors: Dennis Litty, Volker MullerAbstract:Eubacterium limosum KIST612 is one of the few acetogenic bacteria that has the genes encoding for butyrate synthesis from acetyl-CoA, and indeed, E. limosum KIST612 is known to produce butyrate from CO but not from H2 + CO2 . Butyrate production from CO was only seen in bioreactors with cell recycling or in batch cultures with addition of acetate. Here, we present detailed study on growth of E. limosum KIST612 on different carbon and energy sources with the goal, to find other substrates that lead to butyrate formation. Batch fermentations in serum bottles revealed that acetate was the major product under all conditions investigated. Butyrate formation from the C1 compounds carbon dioxide and hydrogen, carbon monoxide or formate was not observed. However, growth on glucose led to butyrate formation, but only in the stationary growth phase. A maximum of 4.3 mM butyrate was observed, corresponding to a butyrate:glucose ratio of 0.21:1 and a butyrate:acetate ratio of 0.14:1. Interestingly, growth on the C1 substrate methanol also led to butyrate formation in the stationary growth phase with a butyrate:methanol ratio of 0.17:1 and a butyrate:acetate ratio of 0.33:1. Since methanol can be produced chemically from carbon dioxide, this offers the possibility for a combined chemical-biochemical production of butyrate from H2 + CO2 using this acetogenic biocatalyst. With the advent of genetic methods in acetogens, butanol production from methanol maybe possible as well.
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a na a1ao atp synthase with a v type c subunit in a mesophilic bacterium
FEBS Journal, 2020Co-Authors: Dennis Litty, Volker MullerAbstract:A1 AO ATP synthases with a V-type c subunit have only been found in hyperthermophilic archaea which makes bioenergetic analyses impossible due to the instability of liposomes at high temperatures. A search for a potential archaeal A1 AO ATP synthase with a V-type c subunit in a mesophilic organism revealed an A1 AO ATP synthase cluster in the anaerobic, acetogenic bacterium Eubacterium limosum KIST612. The enzyme was purified to apparent homogeneity from cells grown on methanol to a specific activity of 1.2 U·mg-1 with a yield of 12%. The enzyme contained subunits A, B, C, D, E, F, H, a, and c. Subunit c is predicted to be a typical V-type c subunit with only one ion (Na+ )-binding site. Indeed, ATP hydrolysis was strictly Na+ -dependent. N,N'-dicyclohexylcarbodiimide (DCCD) inhibited ATP hydrolysis, but inhibition was relieved by addition of Na+ . Na+ was shown directly to abolish binding of the fluorescence DCCD derivative, NCD-4, to subunit c, demonstrating a competition of Na+ and DCCD/NCD-4 for a common binding site. After incorporation of the A1 AO ATP synthase into liposomes, ATP-dependent primary transport of 22 Na+ as well as ΔµNa+ -driven ATP synthesis could be demonstrated. The Na+ A1 AO ATP synthase from E. limosum is the first ATP synthase with a V-type c subunit from a mesophilic organism. This will enable future bioenergetic analysis of these unique ATP synthases.
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Energy Conservation Model Based on Genomic and Experimental Analyses of a Carbon Monoxide-Utilizing, Butyrate-Forming Acetogen, Eubacterium limosum KIST612
Applied and Environmental Microbiology, 2015Co-Authors: Jiyeong Jeong, Johannes Bertsch, Verena Hess, Sunju Choi, In-geol Choi, In Seop Chang, Volker MullerAbstract:Eubacterium limosum KIST612 is one of the few acetogens that can produce butyrate from carbon monoxide. We have used a genome-guided analysis to delineate the path of butyrate formation, the enzymes involved, and the potential coupling to ATP synthesis. Oxidation of CO is catalyzed by the acetyl-coenzyme A (CoA) synthase/CO dehydrogenase and coupled to the reduction of ferredoxin. Oxidation of reduced ferredoxin is catalyzed by the Rnf complex and Na+ dependent. Consistent with the finding of a Na+-dependent Rnf complex is the presence of a conserved Na+-binding motif in the c subunit of the ATP synthase. Butyrate formation is from acetyl-CoA via acetoacetyl-CoA, hydroxybutyryl-CoA, crotonyl-CoA, and butyryl-CoA and is consistent with the finding of a gene cluster that encodes the enzymes for this pathway. The activity of the butyryl-CoA dehydrogenase was demonstrated. Reduction of crotonyl-CoA to butyryl-CoA with NADH as the reductant was coupled to reduction of ferredoxin. We postulate that the butyryl-CoA dehydrogenase uses flavin-based electron bifurcation to reduce ferredoxin, which is consistent with the finding of etfA and etfB genes next to it. The overall ATP yield was calculated and is significantly higher than the one obtained with H2 + CO2. The energetic benefit may be one reason that butyrate is formed only from CO but not from H2 + CO2.