• Journal of the Korean Society for Marine Environment & Energy
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• v.3 no.2
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• pp.3-10
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• 2000

The main purpose of this study were to estimate the benthic fluxes of dissolved inorganic nitrogen (DIN) from the sediment and denitrification rates in tidal flats of the Keum river estuary. Sediment specimens were collected by a core sampler from three stations along the Keum river estuary in April, August and December, 1999. The sediments were composed of 1.18 %, 29.34 % and 69.49 % of gravel and sand, sand and silt, respectively. The mean ignition loss of the sediment was found 6.7 % and its Oxidation Reduction Potential (ORP) was measured -12 mV. The total hydrogen sulfides was determined about 0.26 mg/gㆍdry. The estimated outflux of ammonium was found 11.2 m mole N/m²ㆍday from the sediment, whereas -1.09 m mole N/m²ㆍday of influx was obtained for nitrate and nitrite through the incubation experiment of sediment cores. Total DIN flux was 10.2 m mole N/m²ㆍday outflux from the sediment. From the incubation experiments executed with the flux studies, mean denitrification rate was found 30.6 m mole N₂/m²ㆍday measured by the direct assay of N₂ production technique. On the basis that DIN flux and denitrification rate in sediment of tidal flat of the Keum river estuary are may be effects to control the algal biomass in the coastal environment, it seems inevitable to pay more attention to investigate the flux of DIN and denitrification rate in tidal flat of the Keum river estuary.

• Applied Biological Chemistry
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• v.29 no.4
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• pp.381-391
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• 1986

This study was intended to find out the effects of the inorganic nutrients in the soil and root on the available constituents contents in Angelica gigas Nakai. The correlation between the contents of decursin and decursinol in roots of the wild and cultivated and the inorganic nutrients contents in the soils and roots was investigated. The contents of decursin in the dried root of the wild was higher than that of the cultivated. The ammonium nitrogen contents in soil and the decursin contents in root had the significant negative correlation, whereas the significant positive correlation was obtained the available phosphorus contents. The significant negative correlation was obtained between the decursin contents and the nitrogen contents of root, and the significant positive correlation between the decursin contents and the contents of phosphorus or potassium in roots.

• Journal of the Korea Organic Resources Recycling Association
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• v.22 no.4
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• pp.45-53
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• 2014

This study was conducted to evaluate the effect of developed composted liquid manure(DSCB), which was produced by adding N, P, and K to composted liquid manure(SCB), on the growth of zoysiagrass. Two different N sources used in DSCB were ammonium sulfate(DSCB-A) and urea(DSCB-U), respectively. Fertilizer treatments were designed as follows; non-fertilizer (NF), control (CF; chemical fertilizer), DSCB-Al($200mlm^{-2}$ DSCB-A), DSCB-A2($250mlm^{-2}$ DSCB-A), DSCB-U ($250mlm^{-2}$ DSCB-U) and CF+SCB(CF+$250mlm^{-2}$ SCB). In zoysiagrass, turf color index, chlorophyll index, dry weight and nutrient content were measured. Turf color index and chlorophyll index in DSCB and SCB treatment were increased by 1~3% and 14~28% than those of NF, respectively, and in DSCB-A1, DSCB-A2 and CF+SCB increased by 7~12% than those of CF. As applied with DSCB and SCB, the dry weight of DSCB-A1 and DSCB-A2 was increased by 25% and 19% in than CF, respectively and their nitrogen uptake by 19% and 6%. Evaluated with turf quality and growth, DSCB-A1 was the best and the most efficient in all treatments. These results indicated that application of DSCB-A1 promoted turf quality and growth of zoysiagrass by stimulating a nitrogen uptake, so that it was expected to replace to chemical fertilizers.

• Microbiology and Biotechnology Letters
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• v.8 no.2
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• pp.93-102
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• 1980

Fungi which were capable of producing gluconic acid were isolated from soil and tree leave samples, which had been collected in Seoul ana its vicinity. Among the 19 strains isolated, a strain named arbitrarily KUF-O4 was selected as a test strain chiefty because of its efficiency in gluconic acid production. The strain was identified as an Aspergillus sp. through its morphological properties. Optimum conditions for the gluconic acid production of KUF-O4 were investigated. The results obtained are as follows. 1. An incubation period of at least 30 hours was required for a good yield of gluconic acid. 2. A medium containing 10％ glucose needed at least 3 ％ CaCo$_3$to maintain the optimum pH for the production of gluconic acid during fermentation. 3. As a carbon source, glucose was the most effective one among the carbon sources tested. 4. As a nitrogen source, an ammonium salt was more effective than any other form of nitrogen compounds. 5. As mineral source, a small amount of both KH$_2$PO$_4$and MgSO$_4$was found to be necessary to increase the efficiency of the gluconic acid production.

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.3
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• pp.288-296
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• 1996

The effect of shading on the mineral components, free amino acid, and fatty acid content of tea shoot was examined under different shading conditions. The results are summarized as follows. The content of Total-Nitrogen and theanine in the tea leaves was the highest in the 95% shading as 5.49% and 15580 mg/kg, respectively, while they were the lowest in the unshading. The contents of total free acid were ranged from 24670 to 30210 mg/kg, showing higher content in the 95% shading than that in the unshading. The contents of ammonium nitrogen, potassium, and magnesium were higher in the all treatments of shading than that of unshading but vise versa in calcium content. The content of total fatty acid was the highest in the 55% + 95% shading as 27990 mg/kg, while that of unshading was the lowest as 24356 mg/kg showing the increasing order of $C_{18:3}$, $C_{18:2}$, $C_{18:0}$, $C_{18:1}$, $C_{18:0}$. The quality of tea leaves was improved with the treatment of shading compared to that of unshading showing the best in the 95% shading.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.4
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• pp.394-402
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• 2001

In order to investigate the composition of dried layer, Porphyra yezoensis cultured at the south coast of Korea, the dried laver was analyzed separately for extractive nitrogen, free and combined amino acids, ATP and related compounds and quaternary ammonium basis using specimens collected monthly from January to April 1998. The extractive nitrogen contents of dried layer extracts were $976\~1,196\;mg/100\;g$ (on dry basis). Twenty-eight to thirty-one kinds of free amino acids were found in the dried laver extracts and their total amounts were 5,648-6,845 mg/100 g (on dry basis). The extracts were rich in free amino acids such as alanine, glutamic acid, taurine, phosphoserine and aspartic acid. Eighteen to twenty-two kinds of combined amino acids from oligopeptides were found in the extracts and their total amounts were $1,194\~1,406\;mg/100\;g$ (on dry basis). The amounts of ATP and related compounds were $111.6\~195.5\;mg/100\;g\;(3.30\~6.00{\mu}mol/g$ on dry basis). Homarine was detected in all samples but glycinebetaine, $\beta$-alaninebetaine and $\gamma$-butyrobetaine disappeared during processing, TMAO was detected in all samples but low TMA was found in some. During processing of dried layer, P. yezoensis, free amino acids, ATP and its related compounds were increased but the other constituents such as combined amino acids, TMAO and TMA and betaines were decreased in all specimens.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.4
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• pp.403-411
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• 2001

In order to investigate the composition of dried layer, Porphyra dentata cultured at the south coast of Korea, the dried layer was analyzed for extractive nitrogen, free amino acids, combined amino acids, ATP and its related compounds and quaternary ammonium basis, The extractive nitrogen contents of dried laver extracts were 670-1,304 mg/100 g (on dry basis). From twenty-eight to twenty-nine kinds of free amino acids were found in the dried laver extracts and their total amounts were $2,796\~6,277\;mg/100\;g$ (on dry basis). The extracts were rich in free amino acids such as alanine, taurine, glutamic acid, glutamine and phosphoserine, From eighteen to twenty-one kinds of combined amino acids were found in the extracts and their total amounts were $1,406\~2,142\;mg/100\;g$ (on dry basis). The amounts of ATP and its related compounds were $65.7\~124,7\;mg/100\;g(2.13\sim3.68{\mu}mol/g$ on dry basis), Homarine was detected in all samples but $\beta$-alaninebetaine, $\gamma$-bufobetaine and trigonelline disappeared during processing. TMAO and TMA were detected in all samples. During processing of dried layer, free amino acids, TMAO and TMA were increased but the other constituents such as combined amino acids, ATP and its related compounds and betaines were decreased in all specimens.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.12
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• pp.1710-1718
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• 2016

The objective of this study was to evaluate the effects of supplements with different crude protein (CP) contents on grazing cattle intake, digestibility, ruminal fermentation pattern, and nitrogen (N) metabolism characteristics during the rainy season. Five ruminal and abomasal cannulated Holstein${\times}$Zebu steers (296 kg body weight, BW) were used in a $5{\times}5$ Latin square design. The animals grazed five signal grass paddocks (0.34 ha). The five treatments evaluated were: Control (no supplement) and 1.0 g of supplement/kg BW with 0, 330, 660, and 1,000 g of CP/kg as-fed. The supplement was composed of starch, soybean meal, urea, and ammonium sulphate. There was a positive linear effect ($p{\leq}0.033$) of the CP content in the supplements on the organic matter (OM), CP, and digested OM intakes. The provision of supplements did not increase ($p{\geq}0.158$), on average, total and ruminal digestibilities of OM and CP. However, the increase in CP content in the supplements caused a positive linear effect ($p{\leq}0.018$) on ruminal digestibilities of OM and CP. Additionally, a quadratic effect of the CP contents of the supplements were observed (p = 0.041) for the ruminal digestibility of neutral detergent fiber corrected for ash and protein, with the highest estimate obtained with the CP content of 670 g/kg. The supply of supplements increased (p<0.001) the ruminal ammonia N concentration, which also changed linearly and positively (p<0.001) according to increase in CP content in the supplements. The apparent N balance and relative N balance (g/g N intake) were not, on average, changed ($p{\geq}0.164$) by the supplements supply. However, both showed a tendency of a linear increase ($p{\leq}0.099$) with increasing supplement CP content. The supplements increased (p = 0.007) microbial N production in the rumen, which also changed linearly and positively (p = 0.016) with increasing supplement CP content. In conclusion, protein supplementation in grazing cattle during the rainy season, while stimulating voluntary forage intake, results in higher efficiency of N utilization when compared to energy supplementation. This is a possible response to increased microbial protein synthesis in the rumen and improved N status in the animal body.

• Korean Journal of Environmental Biology
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• v.28 no.3
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• pp.115-124
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• 2010

In order to find out the short-term phytoplankton dynamics during summer season in Jinhae Bay, we investigated the environmental factors and phytoplankton population densities at 16 stations. A total of 66 phytoplankton species were appeared, diatoms occupied more than 80% of total species, and the others were dinoflagellates and raphidophyceaes. The dominant species were diatoms Chaetoceros affinis, C. didymus, C. pseudocurvisetus, Leptocylindrus danicus, Pseudonitzchia pungens, Skeletonema costatum and dinoflagellates Cochlodinium polykrikoides, Gymnodinium impudicum, Karenia mikimotoi, Prorocentrium minimum, Protoperidinium bipes and Scrippsiella trochoidea. According to multidimensional scaling (MSD) and cluster analysis based on phytoplankton community data from each station, the Jinhae bay was divided into two groups. The first group included stations in the inner part of Masan Bay, which is strongly influenced by high nitrogen loading and low salinity by river discharge. The second group included the other remained stations. Based on canonical correspondence analysis (CCA), small-size dinoflagellates K. mikimotoi, P. minimum, P. bipes and S. trochoidea and centric diatom C. pseudocurvisetus and S. costatum, which is dominanted in the inner area of bay, were related with DIN (ammonium, nitrate, nitrite). These results imply that the study area was grouped into the two water masses (inner and outer water of Masan Bay) and inner waters had higher phytoplankton abundances and Chl.a concentration than outer waters. As a result, summer phytoplankton peaks in the inner shallow bay were stimulated by increases in nitrogen and temperature.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.4
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• pp.303-308
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• 2001

To investigate the partitioning of newly absorbed N derived from NO$_3$- and NH$_4$$^{+}$, 6 mM $K^{15}$ NO$_3$ or 3 mM ($^{15}$ NH$_4$)$_2$ was fed continuously in Italian ryegrass (Lolium multiflrum L.) for 7 days. Nitrogen metabolites (nitrate, amino acid, soluble- and insoluble protein) were analyzed at the end of $^{15}$ N feeding. Dry weight in shoot, stubble and root was not significantly different between NO$_3$$^{[-10]}$ and NH$_4$$^{+}$ feeding. Total nitrogen content in all three organs was significantly higher in NH$_4$$^{+}$ than NO$_3$$^{[-10]}$ feeding. Sum on N content in reduced N fractions (amino acids + proteins) in shoot, stubble and roots in NH$_4$$^{+}$ feeding increased by 13.3, 12.5 and 35.4 %, respectively, compared to NO$_3$$^{[-10]}$ feeding. The Relative Specific Activity (RSA, percentage of newly absorbed $^{15}$ N relative to total N in a sample) values of amino acids and insoluble proteins were significantly higher in NH$_4$$^{+}$ feeding. Total amount of newly absorbed $^{15}$ N in NO$_3$$^{[-10]}$ and NO$_3$$^{[-10]}$ feeding was 52.3 and 69.5 mg/plant on dry matter basis, respectively. In both NH$_4$$^{+}$ and NO$_3$$^{[-10]}$ grown plants, most of the N was allocated to the shoot, 67.5% in NH$_4$$^{+}$ feeding and 58.8% NO$_3$$^{[-10]}$ feeding, respectively. The $^{15}$ N amount incorporated in the reduced N compounds (amino acids and proteins) in NH$_4$$^{+}$ grown plants significantly increased by 74.8% compared to NO$_3$$^{[-10]}$ grown plants. The increase of the $^{15}$ N amount assimilated to amino acids in NH$_4$$^{+}$ grown plants was remarkably higher in roots as more than 7.25 times compared to NO$_3$$^{[-10]}$ feeding. These results indicated that Italian ryegrass was much efficiently utilized NH$_4$$^{+}$-N for the synthesis of reduced N compounds.reduced N compounds.