• Applied Biological Chemistry
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• v.37 no.4
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• pp.277-286
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• 1994

The pot experiment using $^{15}N$ isotope dilution technique was carried out to calculate the balance of nitrogen of surface applied urea in the rice-soil system. The $^{15}N$ concentration was determined by stable isotope ratio mass spcetrometer (model: VG ISO-GAS MM622). In the pots with $^{15}N$ labeled urea application at the rates of 15 and 30 kg N/10a, the percentage of nitrogen derived from fertilizer (NDFF) in rice was higher at the rate of 30 kg N/10a (average 89%) than at the rate of 15 kg N/10a (average 64%). However, the recovery as percentage of fertilizer N by rice was higher at the rate of 15 kg N/10a (65.5%) than at the rate of 30 kg N/10a (54.2%). The percentage of the fertilizer N remained in extractable inorganic N form at the rates of 15 and 30 kg N/10a were $13.5%\;(NH_4-N\;5.53%,\;NO_3-N\;7.99%)$ and $16.5%\;(NH_4-N\;7.49%,\;NO_3-N\;8.98%)$ in unplanted soil, and $2.0%\;(NH_4-N\;0.63%,\;NO_3-N\;1.32%)$ and$2.3%\;(NH_4-N\;0.87%,\;NO_3-N\;1.40%)$ in soil planted to rice, respectively. The dominant form of inorganic-N in soil after harvest was $NO_3-N$ form rather than $NH_4-N$ form regardless of urea application rate or rice cultivation. The percentage of the fertilizer N remained in organic N form at the rates of 15 and 30 kg N/10a were 65.0 and 41.8% in unplanted soil, and 23.7 and 26.9% in soil planted to rice, respectively. In conclusion, the efficiency of surface-applied urea was greater at the rate 15 kg N/10a than at the rate of 30 kg N/10a.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.11
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• pp.1213-1221
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• 2006

In this study, granular sludge used in an anaerobic process treating brewery waste was inoculated in a laboratory scale of reactor to induce anaerobic ammonium oxidation(ANAMMOX). The reactor was operated with synthetic wastewater, which prepared at 1:1 ratio of $NH_4^+-N$ over $NO_2^--N$. Changes in nitrogen concentration, COD, alkalinity and gas production were analyzed. There are 3 phases of spanning in experimental period according to influent nitrogen concentration. In the Phase 1, each of the concentration of $NH_4^+-N$ and $NO_2^--N$ were increased from 1.91 $gN/m^3{\cdot}d$ to 14.29 $gN/m^3{\cdot}d$. Ammonium nitrogen loading(same as nitrite nitrogen) was 23.81 $gN/m^3{\cdot}d$ in the Phase 2 and 19.05 $gN/m^3{\cdot}d$ in the Phase 3, respectively $NO_2^--N$ has been removed up to 99% during whole period while the removal efficiency of $NH_4^+-N$ was significantly varied. In Phase 2, $NH_4^+-N$ was removed up to 75%. Microorganisms varied temporally through three phases were characterized by 16s rDNA analysis methods. ANAMMOX bacteria were dominantly found in phase 2 when the removal rate of $NO_2^--N$and $NH_4^+-N$ was the highest up to 99% and 75%, respectively. Due to erroneous exposed to air, the removal efficiency of $NH_4^+-N$ was unexpectedly lowered, but ANAMMOX bacteria still existed.

• Microbiology and Biotechnology Letters
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• v.26 no.2
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• pp.173-178
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• 1998

This study presents the influence of ammonium-nitrogen on microorganisms in swine wastewater. For the anaerobic batch fermentation, two different methods were used. One is the dilution of wastewater with water. The other method is the elimination of ammonium-nitrogen from the wastewater. By addition of MgO into wastewater, non-soluble crystall was formed under alkaline condition as MgNH$_4$PO$_4$6$H_2O$ (MAP). The master culture was adapted in swine wastewater for more than 3 months, in water-dilution method, the dilution of wastewater with 25% water gave us the best result in efficiency of COD removal. Two hundred hours later MAP-treated wastewater showed the efficiency of the COD removal more than 80%. Under same condition obtained none MAP-treated wastewater about 50%. MAP treatment carried out the very effective anaerobic digestion with swine wastewater. The important result in this study is that the low ratio of C:N influenced on anaerobic microorganisms more than high concentration of ammonium nitrogen in swine wastewater. The struvite for the crystallforming has no toxic effect on methanogenic bacteria.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.4
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• pp.431-437
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• 2005

In this study, the profiles of the bacterial regrowth of indigenous bacteria in tap water and Pseudomonas fluorescence P17 were investigated for cases when carbon (glucose), and/or nitrogen ($NO_3^-$-N), and/or phosphorus ($PO_4^{3-}$-P) were added below sufficient nutrient concentration (SNC) and when carbon sources (glucose and acetate) and nitrogen sources ($NH_4^+$-N and $NO_3^-$-N) were added together. The bacterial regrowth was decreased with limitation of nutrients, and were lowered relatively in the sample, which plural nutrients were limited. In addition, phosphate might be the effective nutrient to control the bacterial regrowth in drinking water because the bacterial regrowth was significantly decreased by the limitation of phosphate. In contrast, the bacterial regrowth was retarded with increasing the concentration of $NO_3^-$-N. For simultaneously adding carbon(glucose or acetate) and nitrogen sources ($NH_4^+$-N and $NO_3^-$-N), the regrowth counts appeared highly in the condition, for both glucose and acetate. And, the regrowth was increased with increasing $NH_4^+$-N concentration as a nitrogen source.

• Journal of Animal Environmental Science
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• v.18 no.3
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• pp.221-228
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• 2012

Physicochemical properties of liquid fertilizer samples of resource organization, which are domestically produced and distributed, are analyzed. Major contents of the research results are as follows. 1. The ratio of complete decomposition for liquid fertilizer is 49% at Public Resource Center and 33% at Liquid Fertilizer Supply Center. The combined ratio of both half-decomposed and un-decomposed liquid fertilizers is over 50% at both centers. 2. The ratio of complete decomposed liquid fertilizer, 67%, is the highest in Gangwon and Gyeonggi-do area. The ratio of un-decomposed liquid fertilizer is high in Chungbuk and Chungnam area. The sum of ratios of the half- and un-decomposed is over 60% in the areas except Gyeonnggi-do and Gangwon-do. 3. As a result of regional comparison of the physicochemical properties of liquid fertilizers, concentration variation in most of the items are large, and the degree of uniformity is found to be considerably low. In particular, concentration variation in T-N and $NH_4$-N is the most noticeable. 4. The items that physicochemically correlated to the degree of decomposition of liquid fertilizer are appeared to be T-N, $NH_4$-N, $NO_3$-N, EC, $SCOD_{Mn}$, and ORP. 5. The physicochemical average values of the liquid fertilizer estimated as "complete decomposed" are appeared to be T-N 829 mg/L,$NH_4$-N 517 mg/L, $NO_3$-N 151 mg/L, $SCOD_{Mn}$ 1,205 mg/L, EC 10.32 mS/cm, ORP -117.12 mV.

• Korean Journal of Soil Science and Fertilizer
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• v.34 no.1
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• pp.26-32
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• 2001

Influence of various rates of fractionated raw cow manure on hydraulic conductivity of the soil was observed. The fractionated raw cow manure(hereafter as FRCM) incorporated into soil. The hydraulic conductivity was measured for the double-layered soil while maintaining the water head by 5 cm over the soil surface. The influence on the mobility of $NO_3{^-}$-N transformed from the FRCM was analyzed. The upper layers (Wolgok series) were made with FRCM ranging from 0% to 10.4 % on weight basis for air-dried soil while the organic matter in the bottom layers (Chungwon series) was removed by combustion. The initial bulk densities for both layers were adjusted to $1.25g\;cm^{-3}$. In this experiment the $K_{sat}$ for the upper layer gradually decreased from $4.71{\times}10^{-3}cm\;min^{-1}$ to $1.2{\times}10^{-3}cm\;min^{-1}$ with increasing the rate of the FRCM from 0 % to 10.4%, while the Ksat of the bottom layer was maintained as $3.7cm\;min^{-1}$. For the double-layered soil columns, the $K_{sat}$ decreased with increasing rate of FRCM at the upper layer from $1.7{\times}10^{-3}cm\;min^{-1}$ to $8{\times}10^{-4}cm\;min^{-1}$ as the rate of organic matter increased from 0 % to 10.4 %, while it took almost 7 days to 64 days to obtain the steady state $K_{sat}$ The elution patterns of $NO_3{^-}$-N and $NH_4{^+}$-N showed that the amounts of both $NO_3{^-}$-N and $NH_4{^+}$-N rapidly approached to the maximum ranging from $14.8mmol_c\;kg^{-1}$ to $0.58mmol_c\;kg^{-1}$ as the rate of FRCM decreased from 10.7 % to 0 % which is equivalent to indigenous amount of $NO_3{^-}$-N and $NH_4{^+}$-N. And the amounts of $NO_3{^-}$-N were approximately three or four time than those of $NH_4{^+}$-N, indicating that the transformation rate of $NO_3{^-}$-N was improved by the higher FRCM rate. Thus, the ability of a soil to supply N can be predicted from its mineralization parameters and leaching potentials influenced by water flow regime in soil.

• The Korean Journal of Ecology
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• v.28 no.2
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• pp.93-98
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• 2005

The effects of the presence of a submerged plant, Zizania latifolia, on physico-chemical characteristics, including Eh, pH, and concentrations of nitrogen and phosphorus in the sediments were studied under pot culture condition. It was shown that Eh value at reduced layer of the sediments was higher in the planted pots than in the non-planted. It was also revealed that $NH_4^+-N$ concentration of the sediments in the planted pots was lower than that of the non-planted, which might be due to the uptake by the plants. In contrast, $NO_3^--N$ concentration in the sediment increased in the presence of the plants compared to the non-planted, which might be attributed to oxygen released from the roots to the reduced layer. The concentration of organic phosphorus in the sediments was much higher than that of NAIP at the beginning of the planting experiment. However, at the end of the experiment, it was reversed; NAIP concentration was much higher than that of organic phosphorus, possibly indicating the transformation of organic phosphorus to NAIP during the experimental period. Both concentrations of $NH_4^+-N$ and $PO_4^{3-}-P$ in the overlying and percolated water were lower in the planted pots than in the non-planted. The concentration of $NO_3^--N$ in the percolated water, however, was higher in the planted pots than in the non-planted. The data was discussed with regard to the potential effects of a submerged plant on dynamics of phosphorus and nitrogen in the rhizosphere of the sediment.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.4
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• pp.522-527
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• 2010

Gibberellic acid ($CA_3$) is used in many industries and constitutes the primary gibberellins produced by fungi and bacteria. However, there is no information on $CA_3$ production by Methylobacterium oryzae CBMB20, a novel plant growth promoting bacterium. We investigated the favorable carbon (C) and nitrogen (N) sources and ratios and cultural conditions, such as incubation temperature, pH of the culture medium, and incubation period for the maximum production of $CA_3$ by Methylobacterium oryzae CBMB20. Maximum $CA_3$ production was observed in ammonium mineral salt (AMS) broth supplemented with Na-succinate and $NH_4Cl$ as C and N sources, respectively. The maximum $CA_3$ production was found at the C/N ratio of 5:0.4 g $L^{-1}$. The highest $CA_3$ production was obtained when the bacterial culture was incubated at $30^{\circ}C$ for 96 h at pH 7.

• KSBB Journal
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• v.24 no.2
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• pp.195-200
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• 2009

The effect of nitrogen source on cell growth and benzo[c]phenanthridine alkaloids production by modifying $NO_3\;^-:NH_4\;^+$ ratio in cell suspension culture of Eschscholtzia califarnica was investigated. When total nitrogen concentration is maintained (60 mM), maximum benzo[c]phenanthridine alkaloids production is about 60.72 mg/L at 50:10 (mol/mol). This productivity was 3.8 times higher than that obtained when cells were grown instandard MS medium. The decrease of $NO_3\;^-:NH_4\;^+$ ratio at 60 mM of total nitrogen caused the decline of both growth and benzo[c]phenanthridine alkaloids production. Under the same concentration of $N0_3\;^-$ (50 mM), higher concentration of $NH_4\;^+$ inhibited cell growth strongly but induced alkaloids production slightly. Also, under the same concentration of $NH_4\;^+$ (25 mM), higher concentration of $N0_3\;^-$ induced alkaloids production strongly but high concentration of $N0_3\;^-$ (${\geq}$100 mM) interfered alkaloids instead. Maximum benzo[c]phenanthridine alkaloids production is about 62.71 mg/L at 50:25 (mol/mol). These results suggest that higher biomass and higher alkaloids production could be obtained by optimizing each nitrogen concentration as well as $NO_3\;^-:NH_4\;^+$ ratio in the culture medium. Nitrate and ammonium in culture medium have distinct role in the regulation of growth and alkaloids production; ammonium had a strong influence on growth while nitrate had an influence on alkaloids production.

• Journal of Bio-Environment Control
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• v.9 no.2
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• pp.85-93
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• 2000

This study was carried out to investigate the effects of several substrates and ratio of NO3--N to NH4--N in nutrient solution on growth, yield and mineral uptake of sweet pepper(Capsicum annuum L.) in bag culture. The content of minerals such as P, K, Ca and Mg showed difference in concentration among media: P and Mg were the highest in vermiculite in vermiculti+rice hull, K in perlite+vermiculite and Ca in perlite+peatmoss; with the lowest in the single perlite medium respectively, Ca of mineral made fairly higest level in concentration compared with the others in all of the media. The concentration of mineral content was lower in the ratio of 8:2 than that of 10:0. Admitting that the pH made difference depending on the kind of substrates and ratios of NO3--N to NH4--N. The pH of 10:0 ratio in all the substrates was higher and more stable than that of 8:2. The range of EC in all the substrates showed from 1.78ds·m-1 to 2.10 ds·m-1, which was optimum range for growth of sweet pepper, and range of EC is larger in 8:2 ratio than that in 10:0 ratio. Plant height and stem diameter were nothing to do with the kind of substrates, but leaf area was the largest at vermiculite+rice hull of the 8:2 ratio, fresh and dry weights were heavier at peatmoss+carbonized rice hull, but were the lightest at perlite. All indexes related to the growth which had something to do with the kind of substrates higher in 8:2 ratio than those in 10:0 ratio. The number of fruit and fresh weight related to the ratio of the 8:2 were the highest as 17.5 at vermiculite+rice hull with 1,588g of fresh weight, while the yield from perlite was the lowest. The number of fruit was the highest as 16.4 at virmiculite+rice hull, yield was the higest as 1,394a at perlite+ peatmoss. The yield of 8:2 ratio at all substrates was higher than that of 10:0 ratio. Of the mineral content related to the plant part, K+ and Mg2+ were higher in concentration at leaf; Ca2+ were higher at root; PO4- was higher at stem and fruit; The content of mineral showed no difference between the ratio of the 8:2 and the ratio of the 10:0 with no regrading to the difference of mineral content among substrates; and K+, Ca2+, and Mg2+ uptake of sweet pepper were higher at 10:0 ratio than that of 8:2; 2while PO4- uptake of sweet pepper was lower at 10:0 ratio than that of 8:2 ratio.