• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.619-620
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• 2001

Lignin peroxidase was produced by free cells of Phanerochaete chrysosporium YU in shaking-flask batch cuture. Without aerating, the maximum activity was 785U/L. As nitrogen source, ammonium tartrate was used for LiP production and 0.02% ammonium tartrate concentration showed the highest potential for LiP prodution.

• Journal of the Korea Organic Resources Recycling Association
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• v.21 no.1
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• pp.13-24
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• 2013

• Microbiology and Biotechnology Letters
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• v.48 no.1
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• pp.72-78
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• 2020

The dynamics of nitrogen compounds and RNA-based functional genes were characterized in the nitrification-denitrification coupling process. For the removal of residual ammonium, intermittent aeration was introduced in the denitrification reactor. N₂O production was not observed in both reactors. In both reactors, the nitrifying genes (achaeal-amoA, bacterial-amoA and hor) and denitrifying genes (narG, nirK, norB and nosZ) had a copy number of 3.92 × 10²-7.25 × 10⁵ and 2.85 × 10²-3.06 × 10⁴ per ng of DNA, respectively. These results suggest that denitrification and nitrification reactions occur in both the nitrification and denitrification reactors, respectively. Therefore, the coupling process is a promising one for the conversion of ammonium to nitrogen without generating N₂O.

• Journal of Microbiology and Biotechnology
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• v.4 no.2
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• pp.146-150
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• 1994

Production of poly-$\beta$-hydroxybutyrate (PHB) in fed-batch fermentation was studied. Utilization of carbon for PHB biosynthesis was investigated by using feeding solutions with different ratios of carbon to nitrogen (C/N). It was observed that at a high C/N ratio carbon source was more preferably utilized for PHB accumulation while its consumption for cellular metabolism appeared to be more favored at a low C/N value. A high cell concentration (184 g/l) was achieved when ammonium hydroxide solution was fed to control the pH, which was also utilized as the sole nitrogen source. For the mass production of PHB, two-stage fed-batch operations were carried out where PHB accumulation was observed to be stimulated by switching the ammonium feeding mode to the nitrogen limiting condition. A large amount of PHB (108 g/l) was obtained with cellular content of 80% within 50 hrs of operation.

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.394-397
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• 2000

Lab-scale biofilter was evaluated for the removal of styrene from a waste gas stream. Compost and polyurethane form were used as packing material (50 : 50) and activated sludge from a wastewater treatment plant was innoculated initially. Nitrogen limitation was observed during the biofilter operation and nitrogen source should be properly supplemented. When ammonium sulfate is used as N-source. 200mg carbon was removed for each mg of nitrogen. The effects of the volumetric styrene loading on the styrene elimination capacity (EC) and the removal efficiency (RE) was also tested. The results showed $EC_{max}$ was 4.8kg $C/m^3{\cdot}day$ and above RE 95% was achieved at EBRT 1min.

• Korean Journal of Microbiology
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• v.32 no.3
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• pp.182-185
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• 1994

Effects of nitrogen and carbon sources on the decolorization rate of poly R-478 dye by a white rot basidiomycete Coriorus versicolor IFO 30388 were examined. The fungus exhibited 87.2% of decolorization rate when it was cultured in the state of stationary in a nitrogen-limited medium (pH 4.5) which contained 2.0% glucose, 0.04% ammonium tartrate, 0.02% poly R-478 dye, 2% $KH_2PO_4$, 0.5% $MgSO_4{\cdot}7H_2O$, 0.1% $CaCl_2{\cdot}2H_2O$, 0.002% thiamine-HCl and 10 mM 2,2 dimethylsuccinate (sodium) at $28^{\circ}C$ for 10 days. Decolorization of the dye occurred in the presence of nitrogen source in the medium and decolorization rate increased rapidly after depletion of $NH_4^+$ from the medium.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.20
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• pp.122-133
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• 1975

In recent years, farmers have substituted urea for ammonium sulfate as nitrogen fertilizer in their crop production. Since crops can not take urea itself directly as it is, we attempted to determine the amount of decomposition of urea in soil. It was observed that 25 percent of urea which had initially mixed with soil was decomposed in 10 days at 15$^{\circ}C$ and 80 percent in 2 days at $25^{\circ}C$. Therefore, it was considered that large amount of urea could be lost in cool season and cool areas. In the other experiment, ammonium sulfate, as a source of sulfur, was so mixed with urea that the ratio of sulfur to nitrogen would be 15 percent. Small amount of dolomite was also added to this mixture and the resulting fertilizer was applied on the rice plants. Eight percent of yield increase was obtained together with the increased protein content in brown rice.

• Journal of Microbiology and Biotechnology
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• v.29 no.12
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• pp.1993-2005
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• 2019

Thermophilic anaerobic digestion (TAD) is characterized by higher biogas production rates as a result of assumedly faster microbial metabolic conversion rates compared to mesophilic AD. It was hypothesized that the thermophilic microbiome with its lower diversity than the mesophilic one is more susceptible to disturbances introduced by alterations in the operating factors, as an example, the supply of nitrogen-rich feedstock such as poultry manure (PM). Laboratory scaled TAD experiments using cattle slurry and increasing amounts of PM were carried out to investigate the (in-) stability of the process performance caused by the accumulation of ammonium and ammonia with special emphasis on the microbial community structure and its dynamic variation. The results revealed that the moderate PM addition, i.e., 25% (vol/vol based on volatile substances) PM, resulted in a reorganization of the microbial community structure which was still working sufficiently. With 50% PM application, the microbial community was further stepwise re-organized and was able to compensate for the high cytotoxic ammonia contents only for a short time resulting in consequent process disturbance and final process failure. This study demonstrated the ability of the acclimated thermophilic microbial community to tolerate a certain amount of nitrogen-rich substrate.

• Korean Journal of Microbiology
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• v.11 no.3
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• pp.121-128
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• 1973

In order to clarify the best cultural conditions of Rhizopus niveus the effects of aeration, pH and various nutrients, such as different carbon and nitrogen sources, vitamins, and growth substances, on the mycelial growth were studied through liquid culture, and amylase activities of the fungus at different cultural periods were measured. Soluble starch, xylose and galactose are excellent sources of carbon for growth of the fungus. Sorbose and lactose are utilized slightly for growth. peptone, ammonium sulfate and alanine are excellent nitrogen sources for growth, tyrptophane nad potassium nitrate are utilized slightly for growth and sodium nitrite is not utilized. Thiamine nad gibberellin are excellent growth substances for the fungal growth, and biotin, nicotinamide and indole acetic acid (IAA) are also effective. Rhizopus niveus grows better at rotatory culture than at stationary culture and earlier growth of the fungus increases remarkably at rotatory culture. Optimum pH than at pH3. Growth increases linerly with an increase of soluble starch content up to 100g per liter medium, but 5 grams of ammonium sulfate per liter is the optimum nitrogen concentration for growth, if Pfeffer's medium is employed. Amylase activities of Rhizopus at different cultural periods showed that the maximum amylase production takes place after the cell population has reached its peak in the culture. Dextrinogenic amylase production has reached maximum at stationary phase, and maximum saccharogenic maylase production takes place in the pahse of negative gorwth acceleration.

• Journal of Korean Society on Water Environment
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• v.23 no.2
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• pp.244-250
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• 2007

This study was carried out to obtain the optimum design factors for an eletrolytric flotation reactor. When the effluent of the leachate treatment facility was treated under the condition of 10 volts, 30 minutes, at the Al-Al electrode system; COD removal efficiency was 45%, and total phosphorus removal efficiency was 98%. The high removal efficiency was caused by the fact that phosphate was removed by leaching $Al^{3+}$ from two electrodes. The leachate containing high ammonium nitrogen concentration was treated by a batch test under the condition of 60 minutes reaction time and added chloride ion; ammonium nitrogen removal efficiency was 89%. This high efficiency was affected by added chloride ion to wastewater. To find the optimum current density and voltage of the leachate containing chloride ion (ratio of $Cl^-/NH_4-N$ is 11) a electrochemical polarization curve was used. These values were found to be $4.5mA/cm^2$ and about 2.1 V, respectively. When C-Al electrode system was used at a batch test, the total nitrogen removal efficiency was increased by 1.8 to 3.3 times, compared to Al-Al electrode system due to high $Cl_2$ gas production.