• Journal of Korean Society on Water Environment
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• v.20 no.4
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• pp.339-345
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• 2004

The characteristics of $H_2$ production from livestock wastewater were investigated through an anaerobic acid forming process using Clostridium beijerinckii and the photosynthetic process using Rhodobacter sphaeroides. The submerged separation membrane was installed in the acid forming reactor, The photosynthetic process is composed of two reactors(photosynthetic reactor 1 and photosynthetic reactor 2) which is connected continually. The removal rate of COD and the production of volatile fatty acid(VFA) in the acid forming process were approximately 50% and 1000mg/L, respectively. The 70% of COD in the effluent of acid forming process was removed through the photosynthetic process. The production of $H_2$ in the photosynthetic reactor 1 and 2 was 50 and $25mLH_2/gVFA_{COD}$, respectively. The values of Y in acid forming reactor, photosynthetic reactor 1 and 2 was 0.2263, 0.0601 and 0.0393, respectively. The acetic acid and butyric acid produced in acid forming process were converted to $H_2$ by photosynthetic bacteria.

• Journal of Marine Bioscience and Biotechnology
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• v.1 no.4
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• pp.292-297
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• 2006

Lab-scale and pilot-scale productions of photosynthetic bacteria, that were able to efficiently treat wastewater from aquacultural farm, were experimented for their highly-pure culture. The results of experiments in a gas pack reactor, an anaerobic flask and a flask using $N_2$ gas as N-source showed that only photosynthetic bacteria formed red colonies on agar plate and their purity was over 90% in a colony, observed under a microscope. It was found that the basal medium could most promote the growth of photosynthetic bacteria, confirmed by experiments of serial cultures on various media. Under the culture conditions, the specific growth rate was found to be $0.18h^{-1}$ from the culture in 5L bioreactor and the same value could be obtained in pilot-scale production.

• Journal of Microbiology and Biotechnology
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• v.12 no.4
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• pp.643-648
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• 2002

For wastewater treatment and utilization of the biomass, a photosynthetic bacterium was isolated based on its cell growth rate, cell mass, and assimilating ability of organic acids. The isolate was a Gram-negative rod-shaped bacterium that contained a single polar flagellum and formed a lamellar intracytoplasmic membrane (ICM) system, including bacteriochlorophyll $\alpha$. The major isoprenoid quinone component was identified as ubiquinone Q-10, and the fatty acid composition was characterized as to contain relatively large amount of C-16:0 (18.74%) and C-18:1 (59.23%). Based on its morphology, phototrophic properties, quinone component, and fatty acid composition, the isolate appeared to be closely related to the Rhodopseudomonas subgroup of purple nonsulfur bacteria. A phylogenetic analysis of the isolate using its 16S rRNA gene sequence data also supported the phenotypic findings, and classified the isolate closely related to Rhodopseudomonas palustris. Accordingly, the nomenclature of the isolate was proposed as Rhodopseudomonas palustris KUGB306. A bench-scale photosynthetic bacteria (PSB) reactor using the isolate was designed and operated for the treatment of soybean curd wastewater.

• Journal of environmental and Sanitary engineering
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• v.20 no.2 s.56
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• pp.12-20
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• 2005

Most of sewage treatment plants in Korea is operated for the removal of organic material. Because of low C/N ratio of domestic wastewater it is very difficult to remove nitrogen and phosphorus from wastewater. Therefore C/N ratio is key factor for the removed of nitrogen and phosphorus. PSB(photosynthetic bacteria) can remove the nutrient materials, so this study is focused on PSB characterization of nutrient removal. PSB is possible to remove nitrogen, phosphorus in anaerobic and aerobic condition. This study try to find out condition of the PSB in SBR reactor, Batch reactor. It consists of three Mode. Mode 1, 2 is to apply activated sludge process and Mode 3 is that seeded PSB in the activated sludge process. As a result of SBR process, Mode 1, 2 which was activated sludge Process showed $79\~90\%,\;66\~90\%$ of SCODcr, $94.67\~95.89\%,\;95.76\~98.56\%$ of TKN, and Mode 3 has $84\~92\%$ of SCODcr, $95.39\~99.52\%$ of TKN removal efficiency, respectively. When comparison with Mode 1, 2 and 3, most of nitrogen and phosphorus is removed at the anaerobic condition in Mode 3. but Mode 1, 2 has just revealed activated sludge process characterization. It would because of characterization of PSB.

• Applied Biological Chemistry
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• v.37 no.4
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• pp.303-309
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• 1994

To develop the treatment process of swine wastewater using Rhodopseudomonas palustris KK14 with high utilizable ability of organic acids, some operating conditions were investigated and optimized in flask-scale and laboratory-scale reactors. The optimal operating conditions in photosynthetic bacteria (PSB) reactor of semi-continuous type were obtained at HRT 6 day, 5% (v/v/day) seeding rate of PSB sludge and 10% (v/v/day) returning rate of PSB return sludge. Under the above operating condition, COD level of the wastewater (initial COD: 10 g/l) was reduced to about 1.7 g/l after 4 days treatment and MLSS was held constant at $4{\sim}5\;g$ per liter. In laboratory-scale process consisted of 5.2 l anaearobic digestion reactor and 15 l PSB reactor, the total removal rates of COD and BOD were increased to 95% and 96% by the continuous operation for 5.36 days, respectively, showing $3kg\;COD/m^3/day$ COD loading rate and 1.1 Kg COD/Kg MLSS/day sludge loading rate in PSB reactor. The offensive odor was considerably removed through the treatment process of swine wastewater.

• Applied Biological Chemistry
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• v.37 no.4
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• pp.295-302
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• 1994

For the development of biological wastewater treatment process using photosynthetic bacteria (PSB), photosynthetic sludge process consisted of anaerobic digestion and PSB reactor were designed for the treatment of swine wastewater and the optimal operating conditions in flask-scale were examined. Photosynthetic bacteria from soil, pond, rice field, ditch etc. were isolated in synthetic medium containing high amount of organic acids and finally isolated one strain KK14 which showed the most degradating ability of organic acids was selected for the treatment of swine wastewater. It was identified as Rhodopseudomonas palustris. In the anaerobic digestion stage, the maximum organic acid productivity was obtained at pH 5.0, $37^{\circ}C$, HRT 2 day and under anaerobic standing condition. The optimal operating conditions of PSB reactor for the treatment of swine wastewater were pH 7.0, $30^{\circ}C$ under 4,000 lux illumination, and optimal initial COD loading (kg COD/kg D. C. W of PSB) was 2 (20% v/v seeding) in the main purification stage. Maximum removal rate of COD reached 92% under the above optimal conditions for 5 days.

• Korean Journal of Microbiology
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• v.42 no.4
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• pp.306-312
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• 2006

Disposal of food garbage in most large cities is very troublesome task. To date, microbiological treatment has been received an attention as a garbage decomposition process. In this study, the inoculation effect of some cellulase, amylase and protease-producing bacteria and photosynthetic bacteria on food garbage treatment was examined. They were added into a treatment reactor specially designed in this study together with food garbage and incubated in various conditions for 15 days and the removals of food garbage and foul smell produced during the treatment were analyzed. Average decomposition percentages of the inoculated food garbage in treatment reactor were 11 and 18.8% under intermittent aeration (once in a day) and continuous aeration conditions (2 L/min), respectively, and these were higher than removal percentages in the corresponding uninoculated reactors,3.4 and 13.8%. Optimal pH and temperature for food garbage decomposition by inoculated bacteria were pH 7.0 and $30^{\circ}C$. Maximal decomposition percentage in the inoculated food garbage was 35% under the optimal condition (pH 7, $30^{\circ}C$, and continuous aeration). The malodor compounds generated from food garbage treatment such as complex foul smell and sulfur compounds were effectively reduced about 84% and 25.5%, respectively, with a biofilter composed of purple nonsulfur bacteria trapped in sponge. This decomposing capability of food garbage by these bacteria can be utilized for the rapid and efficient treatment of food garbage.

• KSBB Journal
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• v.8 no.3
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• pp.243-255
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• 1993

In this study, it was observed that hydrogen Productivity varied with stirrer speed, bead radius, input glucose concentration and dilution rate in a continuous stirred tank reactor in which immobilized R. rubrum KS-301 was used as a hydrogen-producing bacterium The mass transfer resistance due to cell immobilization was also studied. In order to estimate an effectiveness factor, Des of glucose was first obtained, which was subsequently represented by the correlation equation between Dos and Xb, As a result external mass transfer resistance could be neglected for stirrer speeds greater than 400rpn With bead radius increasing, the hydrogen productivity and internal effectiveness factor decreased. With input 91ucose concentration increasing, the hydrogen productivity and interval and external effectiveness factor increased. Although an Internal effectiveness factor was not affected, hydrogen productivity Increased with dilution rate increasing. An overall effectiveness factor remained nearly constant for the dilution rates investigate4 but increased with input 91ucose concentration increasing.

• Transactions of the Korean hydrogen and new energy society
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• v.15 no.2
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• pp.166-174
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• 2004

Purple non-sulfur bacteria, Rhodobacter sphaeroides KD131 grew to reach the maximum cell concentration in 45 hrs of incubation in the synthetic media containing (NH4)2SO4, L-aspartic acid and succinic acid as the carbon and nitrogen sources, respectively, at 30oC under 8 klux irradiance using halogen lamp. The strain produced hydrogen from the middle of the logarithmic growth phase and continued until the cell growth leveled out. The strain grew and produced hydrogen under the irradiance of 3-30 klux, but cell growth was inhibited over 100 klux. In addition, anaerobic/light culture condition was better than the aerobic/dark on the hydrogen production. Among various photo-bioreactors examined, the flat-vertical reactor manufactured using clear acrylic plastic material showed the best hydrogen production rate at the given culture condition.

• Fisheries and Aquatic Sciences
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• v.25 no.10
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• pp.525-536
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• 2022

Photosynthetic bacteria (PSB) attract considerable interest as useful microorganisms; nevertheless, a generalized culture technique has not been previously reported owing to difficulty in their cultivation. Therefore, a simple culture technique suitable for public use was investigated. Among the PSB tested, the strain Rhodobacter azotoformans EBN-7 was the most suitable for scale-up production because it showed the highest specific growth rate (0.20 h^-1) on basal medium. In scale-up cultivation (500 L), R. azotoformans EBN-7 showed 4.50 × 10¹⁰ colony-forming units mL^-1 (number of viable cells), dry cell weight of 26.8 g/L, and a specific growth rate of 0.15 h^-1. Cultivation using this final culture broth (as seed culture) in a 15 L simple reactor was successful, with maintenance of cell activity evident. For use as seed culture, the maximum allowable preservation period of R. azotoformans EBN-7 at 4℃ was 3 months. When R. azotoformans EBN-7 cultivated in a simple technique was applied to shrimp aquaculture water, NH₄⁺-N was reduced from 0.61 mg/L to 0.24 mg/L (by 60.7%) in 4 days in comparison with the control. Thus, this simple culture technique using R. azotoformans EBN-7 has the potential for a good removal efficiency of NH₄⁺-N, making seed culture easier and suitable for public use.