The Experts below are selected from a list of 543 Experts worldwide ranked by ideXlab platform
Hajime Masukawa - One of the best experts on this subject based on the ideXlab platform.
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Correction: Sakurai, H.; et al. How Close We Are to Achieving Commercially Viable Large-Scale Photobiological Hydrogen Production by Cyanobacteria: A Review of the Biological Aspects. Life 2015, 5, 997⁻1018.
Life (Basel Switzerland), 2018Co-Authors: Hidehiro Sakurai, Hajime Masukawa, Masaharu Kitashima, Kazuhito InoueAbstract:In the published article "How close we are to achieving commercially viable large-scale Photobiological Hydrogen Production by cyanobacteria:[...].
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Increased heterocyst frequency by patN disruption in Anabaena leads to enhanced Photobiological Hydrogen Production at high light intensity and high cell density
Applied microbiology and biotechnology, 2017Co-Authors: Hajime Masukawa, Hidehiro Sakurai, Robert P. Hausinger, Kazuhito InoueAbstract:The effects of increasing the heterocyst-to-vegetative cell ratio on the nitrogenase-based Photobiological Hydrogen Production by the filamentous heterocyst-forming cyanobacterium Anabaena sp. PCC 7120 were studied. Using the uptake Hydrogenase-disrupted mutant (ΔHup) as the parent, a deletion-insertion mutant (PN1) was created in patN, known to be involved in heterocyst pattern formation and leading to multiple singular heterocysts (MSH) in Nostoc punctiforme strain ATCC 29133. The PN1 strain showed heterocyst differentiation but failed to grow in medium free of combined-nitrogen; however, a spontaneous mutant (PN22) was obtained on prolonged incubation of PN1 liquid cultures and was able to grow robustly on N2. The disruption of patN was confirmed in both PN1 and PN22 by PCR and whole genome resequencing. Under combined-nitrogen limitation, the percentage of heterocysts to total cells in the PN22 filaments was 13-15 and 16-18% under air and 1% CO2-enriched air, respectively, in contrast to the parent ΔHup which formed 6.5-11 and 9.7-13% heterocysts in these conditions. The PN22 strain exhibited a MSH phenotype, normal diazotrophic growth, and higher H2 productivity at high cell concentrations, and was less susceptible to photoinhibition by strong light than the parent ΔHup strain, resulting in greater light energy utilization efficiency in H2 Production on a per unit area basis under high light conditions. The increase in MSH frequency shown here appears to be a viable strategy for enhancing H2 productivity by outdoor cultures of cyanobacteria in high-light environments.
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Photobiological Hydrogen Production: Bioenergetics and challenges for its practical application
Journal of Photochemistry and Photobiology C: Photochemistry Reviews, 2013Co-Authors: Hidehiro Sakurai, Hajime Masukawa, Masaharu Kitashima, Kazuhito InoueAbstract:Abstract Photobiological Production of Hydrogen is considered to be one of the most promising technologies for replacing or complementing fossil fuel-derived energy. This review focuses on the bioenergetics of Photobiological Hydrogen Production by various phototrophs, namely purple non-sulfur bacteria, green sulfur bacteria, cyanobacteria, and green algae. We discuss the improvements in Hydrogen Production efficiency and the advances in related technologies that are needed before phototrophs can be used for economically-viable Hydrogen Production. We also discuss some technological aspects such as the cost of nutrients and bioreactors, which should be taken into consideration in designing future plans for the application of Photobiological Hydrogen Production.
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Improvement of Nitrogenase-Based Photobiological Hydrogen Production by Cyanobacteria by Gene Engineering — Genetic Engineering and Culture Conditions towards Improved Photobiological Hydrogen Production by Cyanobacteria
Advanced Topics in Science and Technology in China, 2013Co-Authors: Hidehiro Sakurai, Hajime Masukawa, Masaharu Kitashima, Kazuhito InoueAbstract:We are proposing large-scale H2 Production on the sea surface utilizing nitrogen-fixing cyanobacteria. Their H2 Production activity is based on photosynthesis and nitrogenase activity of the cells. The mutant cells in which the Hydrogenase activity had been eliminated by genetic engineering (ΔHup of Nostoc sp. PCC 7422) accumulated H2 for several weeks when N2 concentration was low. For economical H2 Production in the future, it was pointed out that the reduction of the cost of the bioreactor is very important. We are proposing a bioreactor composed of several layers of plastic film, with at least one having low permeability to H2. We report here that cyanobacteria culture in a transparent plastic bag produced and accumulated H2 for more than 10 days.
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improvement of nitrogenase based Photobiological Hydrogen Production by cyanobacteria by gene engineering genetic engineering and culture conditions towards improved Photobiological Hydrogen Production by cyanobacteria
2013Co-Authors: Hidehiro Sakurai, Hajime Masukawa, Masaharu Kitashima, Kazuhito InoueAbstract:We are proposing large-scale H2 Production on the sea surface utilizing nitrogen-fixing cyanobacteria. Their H2 Production activity is based on photosynthesis and nitrogenase activity of the cells. The mutant cells in which the Hydrogenase activity had been eliminated by genetic engineering (ΔHup of Nostoc sp. PCC 7422) accumulated H2 for several weeks when N2 concentration was low. For economical H2 Production in the future, it was pointed out that the reduction of the cost of the bioreactor is very important. We are proposing a bioreactor composed of several layers of plastic film, with at least one having low permeability to H2. We report here that cyanobacteria culture in a transparent plastic bag produced and accumulated H2 for more than 10 days.
Hidehiro Sakurai - One of the best experts on this subject based on the ideXlab platform.
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Correction: Sakurai, H.; et al. How Close We Are to Achieving Commercially Viable Large-Scale Photobiological Hydrogen Production by Cyanobacteria: A Review of the Biological Aspects. Life 2015, 5, 997⁻1018.
Life (Basel Switzerland), 2018Co-Authors: Hidehiro Sakurai, Hajime Masukawa, Masaharu Kitashima, Kazuhito InoueAbstract:In the published article "How close we are to achieving commercially viable large-scale Photobiological Hydrogen Production by cyanobacteria:[...].
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Increased heterocyst frequency by patN disruption in Anabaena leads to enhanced Photobiological Hydrogen Production at high light intensity and high cell density
Applied microbiology and biotechnology, 2017Co-Authors: Hajime Masukawa, Hidehiro Sakurai, Robert P. Hausinger, Kazuhito InoueAbstract:The effects of increasing the heterocyst-to-vegetative cell ratio on the nitrogenase-based Photobiological Hydrogen Production by the filamentous heterocyst-forming cyanobacterium Anabaena sp. PCC 7120 were studied. Using the uptake Hydrogenase-disrupted mutant (ΔHup) as the parent, a deletion-insertion mutant (PN1) was created in patN, known to be involved in heterocyst pattern formation and leading to multiple singular heterocysts (MSH) in Nostoc punctiforme strain ATCC 29133. The PN1 strain showed heterocyst differentiation but failed to grow in medium free of combined-nitrogen; however, a spontaneous mutant (PN22) was obtained on prolonged incubation of PN1 liquid cultures and was able to grow robustly on N2. The disruption of patN was confirmed in both PN1 and PN22 by PCR and whole genome resequencing. Under combined-nitrogen limitation, the percentage of heterocysts to total cells in the PN22 filaments was 13-15 and 16-18% under air and 1% CO2-enriched air, respectively, in contrast to the parent ΔHup which formed 6.5-11 and 9.7-13% heterocysts in these conditions. The PN22 strain exhibited a MSH phenotype, normal diazotrophic growth, and higher H2 productivity at high cell concentrations, and was less susceptible to photoinhibition by strong light than the parent ΔHup strain, resulting in greater light energy utilization efficiency in H2 Production on a per unit area basis under high light conditions. The increase in MSH frequency shown here appears to be a viable strategy for enhancing H2 productivity by outdoor cultures of cyanobacteria in high-light environments.
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Photobiological Hydrogen Production: Bioenergetics and challenges for its practical application
Journal of Photochemistry and Photobiology C: Photochemistry Reviews, 2013Co-Authors: Hidehiro Sakurai, Hajime Masukawa, Masaharu Kitashima, Kazuhito InoueAbstract:Abstract Photobiological Production of Hydrogen is considered to be one of the most promising technologies for replacing or complementing fossil fuel-derived energy. This review focuses on the bioenergetics of Photobiological Hydrogen Production by various phototrophs, namely purple non-sulfur bacteria, green sulfur bacteria, cyanobacteria, and green algae. We discuss the improvements in Hydrogen Production efficiency and the advances in related technologies that are needed before phototrophs can be used for economically-viable Hydrogen Production. We also discuss some technological aspects such as the cost of nutrients and bioreactors, which should be taken into consideration in designing future plans for the application of Photobiological Hydrogen Production.
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Improvement of Nitrogenase-Based Photobiological Hydrogen Production by Cyanobacteria by Gene Engineering — Genetic Engineering and Culture Conditions towards Improved Photobiological Hydrogen Production by Cyanobacteria
Advanced Topics in Science and Technology in China, 2013Co-Authors: Hidehiro Sakurai, Hajime Masukawa, Masaharu Kitashima, Kazuhito InoueAbstract:We are proposing large-scale H2 Production on the sea surface utilizing nitrogen-fixing cyanobacteria. Their H2 Production activity is based on photosynthesis and nitrogenase activity of the cells. The mutant cells in which the Hydrogenase activity had been eliminated by genetic engineering (ΔHup of Nostoc sp. PCC 7422) accumulated H2 for several weeks when N2 concentration was low. For economical H2 Production in the future, it was pointed out that the reduction of the cost of the bioreactor is very important. We are proposing a bioreactor composed of several layers of plastic film, with at least one having low permeability to H2. We report here that cyanobacteria culture in a transparent plastic bag produced and accumulated H2 for more than 10 days.
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improvement of nitrogenase based Photobiological Hydrogen Production by cyanobacteria by gene engineering genetic engineering and culture conditions towards improved Photobiological Hydrogen Production by cyanobacteria
2013Co-Authors: Hidehiro Sakurai, Hajime Masukawa, Masaharu Kitashima, Kazuhito InoueAbstract:We are proposing large-scale H2 Production on the sea surface utilizing nitrogen-fixing cyanobacteria. Their H2 Production activity is based on photosynthesis and nitrogenase activity of the cells. The mutant cells in which the Hydrogenase activity had been eliminated by genetic engineering (ΔHup of Nostoc sp. PCC 7422) accumulated H2 for several weeks when N2 concentration was low. For economical H2 Production in the future, it was pointed out that the reduction of the cost of the bioreactor is very important. We are proposing a bioreactor composed of several layers of plastic film, with at least one having low permeability to H2. We report here that cyanobacteria culture in a transparent plastic bag produced and accumulated H2 for more than 10 days.
Roger L. Ely - One of the best experts on this subject based on the ideXlab platform.
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Photobiological Hydrogen Production from Synechocystis sp. PCC 6803 encapsulated in silica sol–gel
International Journal of Hydrogen Energy, 2009Co-Authors: David J. Dickson, Catherine J. Page, Roger L. ElyAbstract:Abstract Hydrogen Production was measured from viable wild-type and M55 mutant cells of Synechocystis sp. PCC 6803 encapsulated in silica sol–gel derived from tetraethoxysilane, tetramethoxysilane, and a mixture of tetraethoxysilane with methyltriethoxysilane. Glycerol and polyethylene glycol were used as additives in concentrations up to 14 wt.% to increase porosity and pore connectivity and to reduce stress on the encapsulated cells. Mixtures were evaluated for Hydrogen Production in a high-throughput screening assay, and samples were imaged with environmental scanning electron microscopy. Compositions showing improved H 2 Production were selected for further study via quantitative analysis of H 2 Production in GC vial assays. H 2 Production activity was monitored for up to 5 days and H 2 Production from encapsulated cells was observed at levels comparable to or exceeding cells suspended in liquid media.
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Photobiological Hydrogen Production from synechocystis sp pcc 6803 encapsulated in silica sol gel
International Journal of Hydrogen Energy, 2009Co-Authors: David J. Dickson, Catherine J. Page, Roger L. ElyAbstract:Abstract Hydrogen Production was measured from viable wild-type and M55 mutant cells of Synechocystis sp. PCC 6803 encapsulated in silica sol–gel derived from tetraethoxysilane, tetramethoxysilane, and a mixture of tetraethoxysilane with methyltriethoxysilane. Glycerol and polyethylene glycol were used as additives in concentrations up to 14 wt.% to increase porosity and pore connectivity and to reduce stress on the encapsulated cells. Mixtures were evaluated for Hydrogen Production in a high-throughput screening assay, and samples were imaged with environmental scanning electron microscopy. Compositions showing improved H 2 Production were selected for further study via quantitative analysis of H 2 Production in GC vial assays. H 2 Production activity was monitored for up to 5 days and H 2 Production from encapsulated cells was observed at levels comparable to or exceeding cells suspended in liquid media.
Inci Eroglu - One of the best experts on this subject based on the ideXlab platform.
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A compact tubular photobioreactor for outdoor Hydrogen Production from molasses
International Journal of Hydrogen Energy, 2017Co-Authors: Emine Kayahan, Inci Eroglu, Harun KokuAbstract:Abstract Hydrogen can be produced sustainably by photofermentation of biomass. For an economically feasible operation, the process should be implemented outdoors using low-cost organic material. In the current study, molasses from a sugar factory was utilized for photofermentative Hydrogen Production. The experiment was run with Rhodobacter capsulatus YO3 (hup − ) in fed-batch mode under outdoor conditions in Ankara between July 12, 2015 and July 24, 2015. The stacked U-tube photobioreactor (9 L) designed for outdoor Photobiological Hydrogen Production by our group was used. The design consists of 4 stacked U-tubes and 2 vertical manifolds. During the operation, the sucrose concentration in the reactor was adjusted to 5 mM daily by diluting the molasses. Maintaining pH at the desired level (around 7.0) was the main challenge of the operation. The pH value was eventually stabilized at 5.9 and Hydrogen Production was sustained for 8 days with continuous feeding of molasses. The maximum productivity was found as 0.31 mol H 2 /(m 3 h). In this study, a long term Photobiological Hydrogen Production from molasses under outdoor conditions was demonstrated for the first time.
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Implementation and analysis of temperature control strategies for outdoor Photobiological Hydrogen Production
Bioprocess and Biosystems Engineering, 2016Co-Authors: Dominic Deo Androga, Basar Uyar, Harun Koku, Inci ErogluAbstract:For outdoor Photobiological Hydrogen Production, the effective control of temperature in photobioreactors is a challenge. In this work, an internal cooling system for outdoor tubular photobioreactors was designed, built, and tested. The temperatures in the reactors with bacteria were consistently higher than those without bacteria, and were also strongly influenced by solar irradiation and ambient air temperature. The cooling protocol applied successfully kept the reactor temperatures below the threshold limit (38 °C) required for the bioprocess and provided a uniform distribution of temperature along the reactor tube length. The biomass growth and Hydrogen Production were similar in the reactors cooled co-currently and counter-currently. The biomass growth rate was 0.1 l/h, the maximum Hydrogen Production rate was 1.28 mol/m^3/h, and the overall Hydrogen yield obtained was 20 %. The change in the biomass was fitted using the logistic model while cumulative Hydrogen Production was fitted using the modified Gompertz equation.
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Hydrogen productivity of photosynthetic bacteria on dark fermenter effluent of potato steam peels hydrolysate
International Journal of Hydrogen Energy, 2011Co-Authors: Nilufer Afsar, Meral Yücel, Ufuk Gündüz, Ebru Ozgur, Muazzez Gurgan, Sevilay Akkose, Inci ErogluAbstract:Abstract Hydrogen productivities of different photosynthetic bacteria have been searched on real thermophilic dark fermentation effluents (DFE). The results obtained with potato steam peels hydrolysate (PSP) DFE were compared to glucose DFE. Photobiological Hydrogen Production has been carried out in indoor, batch photobioreactors using several strains of purple non-sulfur (PNS) bacteria such as Rhodobacter capsulatus (DSM1710), Rhodobacter capsulatus hup- (YO3), Rhodobacter sphaeroides O.U.001 (DSM5864), Rb. sphaeroides O.U.001 hup- and Rhodopseudomonas palustris. The efficiency of photofermentation depends highly on the composition of the effluent and the PNS bacterial strain used. Rb. sphaeroides produced the highest amount of Hydrogen on glucose DFE. Rb. capsulatus gave better results on PSP DFE. This study demonstrates that Photobiological Hydrogen Production with high efficiency and productivity is possible on thermophilic dark fermentation effluents. Consequently, a sequential operation of dark fermentation and photofermentation is a promising route to produce Hydrogen, and it provides a higher Hydrogen yield compared to single step processes.
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Evaluation of Hydrogen Production by Rhodobacter sphaeroides O.U.001 and its hupSL deficient mutant using acetate and malate as carbon sources
International Journal of Hydrogen Energy, 2009Co-Authors: Goekhan Kars, Meral Yücel, Ufuk Gündüz, Gábor Rákhely, Kornél L. Kovács, Inci ErogluAbstract:Rhodobacter sphaeroides O.U.001 is one of the candidates for Photobiological Hydrogen Production among purple non-sulfur bacteria. Hydrogen is produced by Mo-nitrogenase from organic acids such as malate or lactate. A hupSL in frame deletion mutant strain was constructed without using any antibiotic resistance gene. The Hydrogen Production potential of the R. sphaeroides O.U.001 and its newly constructed hupSL deleted mutant strain in acetate media was evaluated and compared with malate containing media. The hupSLR. sphaeroides produced 2.42 l H2/l culture and 0.25 l H2/l culture in 15 mM malate and 30 mM acetate containing media, respectively, as compared to the wild type cells which evolved 1.97 l H2/l culture and 0.21 l H2/l culture in malate and acetate containing media, correspondingly. According to the results, hupSLR. sphaeroides is a better Hydrogen
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Photobiological Hydrogen Production by using olive mill wastewater as a sole substrate source
International Journal of Hydrogen Energy, 2004Co-Authors: Ela Eroglu, Meral Yücel, Lemi Turker, Ufuk Gündüz, Inci ErogluAbstract:Abstract In the present work olive mill wastewater (OMW) collected from West Anatolia—Turkey during 2001, containing 36.02 g carbon, 5.26 g Hydrogen, and 0.96 g nitrogen in 100 g suspended solid was used as a sole substrate for the Production of Hydrogen gas by Rhodobacter sphaeroides O.U.001 in 400 ml glass, column-photobioreactors. Hydrogen Production studies on diluted-OMW were investigated in the range of 20% (v/v) and 1% (v/v) OMW containing media. Below 5% OMW containing media, bacterial growth rate fitted well to the logistic model where Hydrogen Production was observed for the ones below 4% OMW. A maximum Hydrogen Production potential (HPP) of 13.9 l H 2 / l OMW was obtained at 2% OMW. During the biological Hydrogen Production process, chemical oxygen demand (COD) of the diluted wastewater decreased from 1100 to 720 mg / l ; biochemical oxygen demand (BOD) decreased from 475 to 200 mg / l , and the total recoverable phenol content (ortho- and meta-substitutions) decreased from 2.32 to 0.93 mg / l . In addition, valuable by-products such as carotenoid (40 mg / l OMW ) and polyhydroxybutyrate (PHB) (60 mg / l OMW ) were obtained. According to these results, OMW was concluded to be a very promising substrate source for bioHydrogen Production process, with additional benefits of its utilization with regard to environmental and economical aspects.
A.g. Murugesan - One of the best experts on this subject based on the ideXlab platform.
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Chlorella vulgaris MSU-AGM 14, a fresh water microalgal strain - growth and Photobiological Hydrogen Production in acid hydrolysate of seaweed Valoniopsis pachynema
International Journal of Hydrogen Energy, 2016Co-Authors: M. Lakshmikandan, A.g. MurugesanAbstract:Abstract Biological Production of Hydrogen was evaluated by introducing microphyte Chlorella vulgaris strain into acid hydrolysate (sulfuric acid) of Valoniopsis pachynema in anaerobic photo fermentation under sulfur deprivated condition. In batch fermentation process, low concentration of acid hydrolysate showed encouraging biomass Production. The maximum level of cultural growth and Photobiological Hydrogen Production was obtained at 30% acid hydrolysate on 8th day along with sustained Production of bioHydrogen up to 6 days. The optimization of substrate concentration and other significant variables (Temperature, pH and CO2 concentration) were examined by Response Surface Methodology. The results revealed that the Production of Photobiological Hydrogen was higher than the batch fermentation with maximum Photobiological Hydrogen Production of about 0.0039 g h−1 L−1, which were achieved at optimum conditions of substrate concentration (3.25 g L−1); temperature (32 °C), pH (7.66) and carbon dioxide concentration (3.96%). The results suggest that, acid hydrolysate of V. pachynema acts as an effective, inexpensive resource for culturing and acquiring bioHydrogen from C. vulgaris strain.
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Enhancement of growth and bioHydrogen Production potential of Chlorella vulgaris MSU-AGM 14 by utilizing seaweed aqueous extract of Valoniopsis pachynema
Renewable Energy, 2016Co-Authors: M. Lakshmikandan, A.g. MurugesanAbstract:Chlorella vulgaris MSU-AGM 14 a freshwater green microalga exhibited Photobiological Hydrogen Production by employing aqueous extract of green seaweed Valoniopsis pachynema. The microalga was isolated from the pond water followed by its screening to study the bioHydrogen Production capability at anaerobic and sulfur depletion conditions with 15 μmol photons m−2 s−1 light illumination. The aqueous extract (10–100%) of green seaweed V. pachynema served as carbon and nitrogen source for their active growth and bioHydrogen Production at varied concentrations. The optimizations of four individual variables (substrate concentration, temperature, pH and carbon dioxide) were examined by using Response Surface Methodology (RSM). The collected bioHydrogen gas samples were analyzed quantitatively and qualitatively by using Gas Chromatography (GC). The 16S rRNA proved that the C. vulgaris MSU-AGM 14 has 609 bp fragment within the chloroplast genome of Chlorella Beijerinck genus. The optimized individual variables were obtained at a concentration of 22.5% of seaweed aqueous extract at a medium pH of 6.8, at a temperature of 32 °C with 5% carbon dioxide for active Photobiological Hydrogen Production. Collectively, the results demonstrate that bioHydrogen Production in C. vulgaris MSU-AGM 14 were increased by employing aqueous extract of green seaweed Valoniopsis pachynema.