• Korean Chemical Engineering Research
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• v.44 no.1
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• pp.16-22
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• 2006

Biological hydrogen production processes are more environment-friendly and less energy intensive than thermochemical and electrochemical processes. The biological process can be divided into two categories: photosynthetic hydrogen production and hydrogen production by dark fermentation. Photosynthetic process produces hydrogen mainly from water and reduces $CO_2$ simultaneously. Dark fermentation is a dark and anaerobic process that produces hydrogen by fermentative bacteria from organic carbon. The article presents a survey of biological hydrogen production processes.

• Journal of Plant Biology
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• v.36 no.4
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• pp.313-319
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• 1993

Photoproduction of hydrogen by free and polyvinylalcohol (PVA)-immobilized spinach chloroplasts was investigated. Immobilization of chloroplast with PVA increased the functional stability of the chloroplast during storage. PVA-immobilized chloroplasts preserved photosynthetic electron transport activity much better than free chloroplasts. The hydrogen production of free chloroplast decreased to 17% of initial activity after storage of six days. The hydrogen production of the PVA-immobilized chloroplast, however, showed 44% of initial activity after storage of 15 days. The maximal rate of hydrogen production was accomplished at 2$^{\circ}C$ under the light intensity above 116 $\mu$E.m-2.s-1. The amount of hydrogen produced was proportional to the chlorophyll concentration. The hydrogen production was inhibited by DCMU treatment, indicating hydrogen production is dependent on photosynthetic electron transport. These results suggest that PVA is a good candidate for the immobilization matrix of chloroplasts for the photoproduction of hydrogen.

• Transactions of the Korean hydrogen and new energy society
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• v.16 no.4
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• pp.315-323
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• 2005

The integrated or the two-stage (dark anaerobic and photosynthetic) fermentation processes were compared for the hydrogen production using purple non-sulfur photosynthetic bacteria, Rhodopseudomonas palustris P4. Cell growth, pH changes and organic acids and bacteriochlorophyll contents were monitored during the processes. Culture broth of Rps. palustris P4 exhibited dark-red during the photosynthetic culture condition, while yellow under the anaerobic condition without light. Rps. palustris P4 grown at the photosynthetic condition evolved 0.38 and 1.33 ml $H_2$/mg-dcw during the dark and the light fermentation, respectively, which were totally 1.71 ml $H_2$/mg-dcw at the two-stage fermentation. The rate of hydrogen production using Rps. palustris P4 grown under the dark anaerobic condition was 2.76 ml $H_2$/mg-dcw which consisted of 0.46 and 2.30 ml $H_2$/mg-dcw from the dark and the photosynthetic fermentation processes, respectively. Rps. palustris P4 grown under dark anaerobic conditions produced $H_2$ 1.6 times higher than that of grown under the photosynthetic condition. However, total fermentation period of the former was 1.5 times slower than that of the latter, because the induced time of hydrogen production during the photosynthetic fermentation was 96 and 24 hours when the seed culture was the dark anaerobic and photosynthetic, respectively. The integrated fermentation process by Rps. palustris P4 produced 0.52 ml $H_2$/mg-dcw(1.01 mol $H_2$/mol glucose), which was 20% of the two-stage fermentation.

• KSBB Journal
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• v.6 no.4
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• pp.351-361
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• 1991

This study is on the investigation of hydrogen production and substrate removal by photosynthetic bacteria. After using of Rhodospillum rubrum KS-301 and IFO 3986, which are photosynthetic bacteria as strains, R. rubrum KS-301 was turned out a better strain. And result of experiment in which glucose and sodium lactate, components of wastewater, were used limiting substrates, showed that the productivity of hydrogen was indifferent with the kind of substrates. In batch experiments using free cells and immobilized whole cells, the decrease in hydrogen productivity was observed in the latter case. From the results of these experiments, specific growth rate of cells, specific utilization rate of glucose, and specific production rate of hydrogen were calculated. And each rate was expressed in the form of Monod equation of which parameters were estimated. Also the optimum condition of hydrogen production for free cells was $30^{\circ}C$, pH 7, and 12,000 Lux, and the optimum immobilized condition was as follows: initial immobilized cell concentration 1.0g/L, sodium alginate concentration 2% and light intensity 12,000 Lux.

• Microbiology and Biotechnology Letters
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• v.13 no.3
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• pp.303-309
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• 1985

Continuous production of hydrogen by Ca alginate-immobilized photosynthetic bacteria was studied in a packed-bed bioreactor. The dilution rate and input concentration of carbonaces substrate were selected as operating parameters. To choose the strain for immobilization, hydrogen productivities of Rhodopseudomonas caposulata 10006 and Rhodospirillum rubrum KS-301 were compared through preliminary batch cultures of their free cells: the former was found to show better hydrogen productivity in spite of its lower specific growth rate. For the continuous production of hydrogen by immobilized R capsulata, the optimum dilution rate was about 0.84 h$^{-1}$ . The Immobilized tells gave better hydrogen yield and conversion efficiency than free ones. And a kinetic parameter K'$_{m}$ was determined for the packed-bed bioreactor, being practically constant for a specific range of dilution rates.s.

• Microbiology and Biotechnology Letters
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• v.20 no.3
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• pp.329-334
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• 1992

For the photoproduction of molecular hydrogen by photosynthetic bacteria in outdoor conditions, we constructed automatically controlled semi-continuous culture system. When the amount of hydrogen gas produced can be measured by a gas meter with a pulse generator, the same amount of substrate consumed for hydrogen production could be supplied by micro pump related with timers. Using the apparatus, we examined hydrogen production with immobilized cells of Rhodopseudomonas sPhaeroides B6 in outdoor conditions. In spite of severe fluctuation of weather and illumination, the culture was maintained under good control with regard to hydrogen productivity. It was possible to automate the semi-continuous outdoor culture of photosynthetic bacteria for hydrogen production.

• Transactions of the Korean hydrogen and new energy society
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• v.21 no.1
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• pp.12-18
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• 2010

Photobiological hydrogen production using Rhodobacter sphaeroides KD131 was studied on the effect of light intensities and nitrogen sources. Media containing malate and glutamate were shown higher hydrogen production rate than that containing succinate and $(NH_4)_2SO_4$ at the $110\;W/m^2$ illumination by halogen lamp at $30^{\circ}C$. Media lacking glutamate as the nitrogen source exhibited higher hydrogen production than that containing glutamate. Initial cell concentration was optimized to 1.0 at the absorbance of 660 nm. Hydrogen production was increased by increasing the light intensity from 0 to $216\;W/m^2$ but the increasing rate declined over $108\;W/m^2$.

• Journal of Microbiology and Biotechnology
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• v.15 no.1
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• pp.131-135
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• 2005

Under sulfur deprived conditions, PS II and photosynthetic $O_2$ evolution by Chlamydomonas reinhardtii UTEX 90 are inactivated, resulting in shift from aerobic to anaerobic condition. This is followed by hydrogen production catalyzed by hydrogenase. We hypothesized that the photosynthetic capacity and the accumulation of endogenous substrates such as starch for hydrogen production might be different according to cell age. Accordingly, we investigated (a) the relationships between hydrogen production, induction time of sulfur deprivation, increase of chlorophyll after sulfur deprivation, and residual PS II activity, and (b) the effect of initial cell density upon sulfur deprivation. The maximum production volume of hydrogen was 151 ml $H_2$/l with 0.91 g/l of cell density in the late-exponential phase. We suggest that the effects of induction time and initial cell density at sulfur deprivation on hydrogen production, up to an optimal concentration, are due to an increase of chlorophyll under sulfur deprivation.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.277-280
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• 2000

Rhodospirillum rubrum KCTC 1372 produced hydrogen from glucose for first 48hrs culture under the anaerobic photosynthetic conditions, and after 48hrs culture the hydrogen production was decreased by the accumulation of producing organic acids in broth. Only 41% of glucose was consumed and 143mL/day/L hydrogen were produced after 96hrs culture. However the hydrogen production and glucose consumption were substantially increased when the pH of the culture broth were controlled to 6.8-7.2. After 96hrs culture, 450mL/day/L hydrogen were produced, and about 80% glucose was consumed. Specific hydrogen production rate was 48.33mL/hr/g cells under pH not controlled, but 45.42mL/hr/g cells under pH controlled.

• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.478-481
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• 2006

Energy is vital to global prosperity, yet dependence on fossil fuels as our primary energy source contributes to global climate change environmental degradation, and health problems. Hydrogen $(H_2)$ offers tremendous potential as a clean renewable energy currency. Hydrogen has the highest gravimetric energy density of any known fuel and is compatible with electrochemical and combustion processes for energy conversion without producing carbon-based emission that contribute to environmental pollution and climate change. Numerous methodologies have been developed for effective hydrogen production. Among them, the biological hydrogen production has gained attention, because hydrogen can be produced by cellular metabolismunder the presence of water and sunlight. The green alga Chlamydomonas reinhardtii is capable of sustained $H_2$ photoproduction when grown under sulfur deprived condition. Under sulfur deprived conditions, PSII and photosynthetic $O_2$ evolution are inactivated, resulting in shift from aerobic to anaerobic condition in the culture. After anaerobiosis, sulfur deprived algal cells induce a reversible hydrogenase and start to evolve $H_2$ gas in the light. According to above principle, we investigated the effect of induction parameters such as cell age, cell density. light intensity, and sulfate concentration under sulfur deprived condition We also developed continuous hydrogen production system by sulfate re-addition under sulfur deprived condition.