• Korean Journal of Microbiology
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• v.20 no.3
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• pp.119-124
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• 1982

As a basic study to elucidate nutritional physiology and composition of synthetic medium of red rotting bacteria, Erwinia carotovora, of ginseng, the effects of hydrogen ion concentration, various kinds of carbon sources, nitrogen source, micrometallic salts and it's concentration on the gorwth of the bacteria were investigated and the results were as follows. Optimal pH in the basal medium for the growth of the bacteria was 6.5. After incubation the pH in culture media was neutralized. Among the various kinds of carbon sources, sucrose, glucose mannitol, but organic acids were not utilized effectively as nutrients. After incubation the pH turned acidic. Alanine as organic nitrogen sources nad ammonium sulfate as inorganic nitrogen promoted the growth, but L-valine and sodium nitrite were the least effective. Ferric chloride 1.0mg/dl and ferrous sulfate 100mg/dl were the most effective as micrometallic sources. Control and boric acid were the least effective. New synthetic medium based on the above results was follows ; Alanine 1.0g, $KH_2PO_4\;1.0g, \;sucrose\;30.0g, \;MgSo_4{\cdot}7H_2O\;0.5g, \;FeCl_3{\cdot}6H_2O\;1.0mg\;thiamine\;200{\gamma}g$, and distilled water 1000ml, pH6.5.

• Korean Journal of Microbiology
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• v.13 no.1
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• pp.37-44
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• 1975

As a basic study to elucidate nutritional physiology and composition of synthetic medium of red rotting bacteria, Erwinia carotovora, of ginseng, the effects of hydrogen ion concentration, various kinds of carbon sources, nitrogen source, micrometallic salts and it's concentration on the gorwth of the bacteria were investigated and the results were as follows. Optimal pH in the basal medium for the growth of the bacteria was 6.5. After incubation the pH in culture media was neutralized. Among the various kinds of carbon sources, sucrose, glucose mannitol, but organic acids were not utilized effectively as nutrients. After incubation the pH turned acidic. Alanine as organic nitrogen sources nad ammonium sulfate as inorganic nitrogen promoted the growth, but L-valine and sodium nitrite were the least effective. Ferric chloride 1.0mg/dl and ferrous sulfate 100mg/dl were the most effective as micrometallic sources. Control and boric acid were the least effective. New synthetic medium based on the above results was follows ; Alanine 1.0g, $KH_2PO_4$ 1.0g, sucrose 30.0g, $MgSo_4$ $7H_2$O 0.5g, $FeCl_36H_2$O 1.0mg thiamine 200.gamma.g, and distilled water 1000ml, pH6.5.

• Journal of Korean Society of Water and Wastewater
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• v.28 no.2
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• pp.195-206
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• 2014

Immobilization of anaerobic ammonium oxidizing bacteria has been studied to enhance the biomass retention of the slowly growing bacteria and the process stability. The purpose of this study was to compare the nitrogen removal efficiency of granular and immobilized anammox bacteria with poly vinyl alcohol and alginate. The specific anammox activity of the granular, homoginized and immobilized anammox bacteria were $0.016{\pm}0.0002gN/gVSS/d$, $0.011{\pm}0.001gN/gVSS/d$ and $0.007{\pm}0.0005gN/gVSS/d$, respectively. Although the activity decreased to 43.7 % of the original one due to low pH and $O_2$ exposure during the homogination and the immobilization, it was rapidly recovered within 7 days in the following continuous culture. When synthetic T-N concentrations of 100, 200, 400, 800 mg/L were fed, the immobilized anammox bacteria showed higher nitrogen removal efficiencies at all operational conditions than those of granular anammox bacteria. When the sludge retention time was shorten below 30.7 days and the reject water was fed, the nitrite removal efficiency of the granular anammox bacteria dropped to 8 % of the initial value, while that of the immobilized anammox bacteria was maintained over 95 % of the initial one. The immobilization with poly vinyl alcohol and alginate would be a feasible method to improve the performance and stability of the anammox process.

• KSBB Journal
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• v.13 no.6
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• pp.638-643
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• 1998

An investigation was made to develop new biofilm medium which could be applied to the Sequencing Batch Biofilm Reactor(SBBR) system for enhanced nutrient removal. 21 kinds of polyurethane media were tested fro adhesion ability for nitrifying bacteria. Nitrification rates were also tested by introducing synthetic wastewater containing ammonium-nitrogen to reactors with biofilm media. It was found that Z96-06 medium had higher selective adhension ability for nitrifying bacteria than the other biofilm media. The nitrification rate was 2.21 mg {{{{ { NH}`_{4 } ^{ +} }}}}-N /L$.$h$.$g MLSS when we operated the SBBR system containing Z96-06. Nitrification rate of the SBBR system increased approximately by 30% compared with that of the Sequencing Batch Reactor(SBR) system which did not contain biological carrier.

• Journal of Korean Society of Water and Wastewater
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• v.11 no.4
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• pp.43-53
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• 1997

In this research, the synthetic livestock wastewater was prepared to study the characteristics of organic matter removal, the change of VFA production, and the amount of gas production with respect to the change of ammonium nitrogen concentration in the waste using anaerobic fixed bed process, which is an anaerobic biofilm process. The HRT and operation temperature were 1 day and $35{\pm}1^{\circ}C$, respectively. Also, the characteristics of organic matter removal and the inhibitory effect on microorganism in the anaerobic process were studied on the organic loading and ammonium nitrogen concentration. The results obtained were as follows: For COD loading of $10kg/m^3$-day and five levels of ammonium nitrogen concentration ranging from 1,000 to 5,000 mg/L, organic removal efficiencies were about 81, 74, 67, 58, and 51%, and gas productions were 3,860, 3,520, 3,240, 3,020, and 2,790 ml/l-day, respectively. Average methane contents in the gas produced on COD loading of $10kg/m^3$-day was about 76%. Throughout the whole period of experiment, remaining VFA (as COD base) in the effluent was over 90% of remaining COD. This result indicated the inhibitory effect of high concentration of ammonium nitrogen through the facts that accumulated VFA was almost COD and organic removal efficiency decreased also with the increase of ammonium nitrogen. Especially, that implys which high concentration of ammonium nitrogen not only inhibits methane forming bacteria, but also acid forming bacteria.

• Journal of Korean Society of Water and Wastewater
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• v.35 no.2
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• pp.135-142
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• 2021

The activity of anaerobic ammonium oxidation (ANAMMOX) immobilized in synthetic media (Poly Ethylene Glycol, PEG) and granular form was evaluated comparatively to investigate the effect of influent nitrogen concentration and exposure of oxygen. In ANAMMOX granule reactor, when concentration of influent total nitrogen increased to 500mg/L, removal efficiency of ammonium, nitrite and nitrate were shown to 90.5±6.5, 96.6±4.9, and 93.2±6.1%, respectively. In the case of the PEG gel, it showed lower nitrogen removal performance, resulting in that the removal efficiency of ammonium, nitrite and nitrate were shown to 83.3±13.0, 96.4±6.1, and 90.3±7.5%, respectively. In second step, when exposed to oxygen, the nitrogen removal performance in the ANAMMOX granule reactor also remained stable, but the activity of PEG gel ANAMMOX was found to be inhibited. Consequently, the PEG gel ANAMMOX was a higher sensitivity than that of granular ANAMMOX with two variables applied in this study.

• Journal of Microbiology and Biotechnology
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• v.10 no.3
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• pp.410-414
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• 2000

The effect of the COD/N ratio on denitrification characteristics was evaluated for the development of a denitrification process. Activated sludge, acclimated to an anoxic condition, was used as the denitrifier consortium (mixture of denitrifying organisms) for enhanced nitrogen removal in a recirculating aquarium system. Synthetic wastewater containing nitrate was used as the influent solution and glucose was used as the carbon source for denitrification. The COD/N ratio varied within a range of 1.5-7.2. The denitrification efficiency was higher than 97% even at a COD/N ratio of 1.5. Under a theoretical COD/N ratio of 3.0, nitrite was detected, however, the amount was less than 1% of the total influent nitrogen. The number of both nitrate-reducing bacteria and denitrifying bacteria reached $3.5{\times}10^5/ml$ with a COD/N ratio of 1.5 after 45 days of operation.

• Journal of the Korea Organic Resources Recycling Association
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• v.10 no.3
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• pp.117-125
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• 2002

This study experimented a possibility of advanced treatment through microorganism that converts $NH_3-N$ to organic nitrogen in wastewater contaminated by ammoniac nitrogen unlike conventional nitrogen removal process. After distributing three kinds of special bacteria that use $NH_3-N$ as a substrate, when those bacteria were cultured in no salt condition and salt condition (3% NaCl), M11 showed better growth in salt condition and M12 showed better growth in no salt condition. However M7l grew well in both no salt condition and salt condition. In the test of glucose effect, maximum growth and removal rate were observed in glucose concentration of 5g/L but in high concentration (1000mg/L as $NH_3-N$) of $NH_3-N$ growth and removal rate were low. Removal rate was the highest in 100mg/L $NH_3-N$ and the fact that concentration of $NO_2-N$ and $NO_3-N$ didn't increase assumed $NH_3-N$ was converted to organic nitrogen. Optimum concentration of $K_2HPO_4$ for phosphorous supply and buffer was 5g/L. Special bacteria distributed could use $NO_2-N$ and $NO_3-N$ as well as $NH_3-N$ as substrates. This study showed that when growth rate of bacteria was high removal rate also was high. It is possible to apply as a method to treat wastewater polluted by $NH_3-N$.

• Korean Journal of Soil Science and Fertilizer
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• v.20 no.2
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• pp.185-192
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• 1987

A green house experiment was conducted to find out the acetylene reducing and $N_2$-fixing activity from photosynthetic and aerobic heterotrophic nitrogen fixing microorganisms in submerged paddy soil under different agricultural locality, soil series, soil texture, soil type, and drainage condition in which samples taken from without nitrogen treatment plot of NPK trials on 16 sites of the farmer's field. The results obtained were summarized as follows: 1. The highest acetylene reducing activity was observed at 7 days after incubation in the light condition (photo synthetic microbes+heterotrophic bacteria) while it was observed at 35 days incubation in the dark condition (heterotrophic bacteria). 2. Among the soil series, photosynthetic nitrogen fixing activity was pronounced more in Jangae, Ogcheon and Hwadong series while lower was obtained in Buyong and Daejeong series. Aerobic heterotrophic nitrogen fixing activity was high in Buyong and Daejong series. 3. Estimated amount of $N_2$-fixation from acetylene reducing activity was equivalented to 3.0 mg in light condition and 4.9 mg/100g/105 days in dark condition. 4. Among the agricultural locality, photosynthetic nitrogen fixing activity was high in rather warm southern part while heterotrophic nitrogen fixing activity was predominated more in mountainous area and Chungcheong continental. 5. Photosynthetic nitrogen fixing activity was predominated in high productive soil while aerobic heterotrophic nitrogen fixing activity was pronounced more in crose coarse sandy soil. 6. The soils properties of high photosynthetic nitrogen fixing activity were constituted of poorly or imperfectly drained clay or clay loam soil while heterotrophic nitrogen fixing activity was pronounced more in well to moderately well drained sandy or sandy loam soil.

• 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.