• Journal of Microbiology and Biotechnology
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• 제28권12호
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• pp.2019-2028
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• 2018

Natural astaxanthin mainly derives from a microalgae producer, Haematococcus pluvialis. The induction of nitrogen starvation and high light intensity is particularly significant for boosting astaxanthin production. However, the different responses to light intensity and nitrogen starvation needed to be analyzed for biomass growth and astaxanthin accumulation. The results showed that the highest level of astaxanthin production was achieved in nitrogen starvation, and was 1.64 times higher than the control group at 11 days. With regard to the optimization of light intensity utilization, it was at $200{\mu}mo/m^2/s$ under nitrogen starvation that the highest astaxanthin productivity per light intensity was achieved. In addition, both high light intensity and a nitrogen source had significant effects on multiple indicators. For example, high light intensity had a greater significant effect than a nitrogen source on biomass dry weight, astaxanthin yield and astaxanthin productivity; in contrast, nitrogen starvation was more beneficial for enhancing astaxanthin content per dry weight biomass. The data indicate that high light intensity synergizes with nitrogen starvation to stimulate the biosynthesis of astaxanthin.

• Membrane and Water Treatment
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• 제11권5호
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• pp.345-351
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• 2020

Eutrophication of surface waters is commonly caused by excessive inputs of nutrients such as nitrogen and phosphorus. Nakdong River basin was chosen as the study area to investigate the effect of point and non-point source pollution of nitrogen on eutrophication in water body. Non-point source inputs of nitrogen accounted for approximately 84% in the total nitrogen input of the upper Nakdong river watershed, which mainly consists of agricultural land and forests. However, point source inputs of nitrogen accounted for 58~85% in the total nitrogen input of the middle and lower watersheds, including urban area. Therefore, for watershed near urban area, control of point source inputs of nitrogen may be an optimal method to control eutrophication. In this respect, the enforcing reduction of nitrogen in the final effluent of wastewater treatment facilities is needed. On the other hand, to enact more stringent nitrogen regulations, the LOT (limit of technology) and environmental impact should be considered. In this study nitrogen data were analyzed to propose new nitrogen regulations.

• Journal of Microbiology and Biotechnology
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• 제17권2호
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• pp.187-194
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• 2007

In order to utilize different nitrogen sources and to survive in a situation of nitrogen limitation, microorganisms have developed sophisticated mechanisms to adapt their metabolism to a changing nitrogen supply. In this communication, the recent knowledge of nitrogen regulation in the amino acid producer Corynebacterium glutamicum is summarized. The core adaptations of C. glutamicum to nitrogen limitation on the level of transcription are controlled by the global regulator AmtR. Further components of the signal pathway are GlnK, a $P_{II}-type$ signal transduction protein, and GlnD. Mechanisms involved in nitrogen control in C. glutamicum regulating gene expression and protein activity are repression of transcription, protein-complex formation, protein modification by adenylylation, change of intracellular localization, and proteolysis.

• Asian-Australasian Journal of Animal Sciences
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• 제11권6호
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• pp.732-738
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• 1998

Three crossbred gilts weighing $61{\pm}2kg$ ($mean{\pm}SD$) and three gilts weighing $52{\pm}3kg $ on the day before the first treatment began (d -1) were used for each of two experiments (Exp. 1 and Exp. 2), respectively. In Exp. 1, all pigs were fed the experimental diet (CP 19%) from d -7 to the end of study (d 21) to verify that nitrogen retention is constant during the 21 -d period. In Exp. 2, pigs were fed the control diet (CP 15.5 %) from d -7 to d 8 and then the low-lysine diet from d 9 to d 16 in order to determine how rapidly dietary changes in amino acid composition results in a new equilibrium for nitrogen metabolism. The amount of urine nitrogen loss was not different over 21 days (p > 0.10). Rates of nitrogen retention were not different among pigs (p > 0.10) nor over time (p > 0.10). Average nitrogen retention during the period was 1.00 g/kg $BW^{0.75}$ per day. The apparent biological value was 41%, which did not change over the 3-week period (p > 0.10). The overall efficiency of nitrogen use for nitrogen retention was 35% (Exp. 1). The amount of nitrogen loss in urine and the efficiency of nitrogen utilization for nitrogen gain reached a new equilibrium within 2 to 3 d after the diet was changed. The low-lysine diet resulted in a 20% increase of nitrogen loss in urine (p < 0.001) and a 9% decline in efficiency of nitrogen use for nitrogen retention (p < 0.001). Nitrogen retention while the pigs were fed the control diet was also higher than the retention when pigs were fed the low lysine diet (p < 0.001). The efficiency of nitrogen use for nitrogen retention in pigs fed the control diet was 57% (Exp. 2), which was higher (p < 0.001) than that from pigs fed the low-lysine diets (52%).

• 한국환경보건학회지
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• 제34권3호
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• pp.199-206
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• 2008

This study was conducted to estimate nitrogen dioxide levels and health risk in various locations/situations for two groups. The nitrogen dioxide levels were measured for residents of a study group (industrial area within 5 km) and a control group (15 km farther), respectively using the nitrogen dioxide filter badge as a passive sampler from August, 2006 to September, 2006. The means of indoor, outdoor, work and personal levels of nitrogen dioxide were $34.65{\pm}1.95\;{\mu}g/m^3$, $34.83{\pm}11.78\;{\mu}g/m^3$, $34.98{\pm}19.11$ and $35.38{\pm}10.74$ respectively in the study area. Mean ratio of indoor to outdoor $NO_2$ concentration was 0.99. The means of indoor, outdoor and personal level of nitrogen dioxide were $23.66{\pm}7.19\;{\mu}g/m^3$, $18.22{\pm}4.06\;{\mu}g/m^3$ and $27.27{\pm}18.93\;{\mu}g/m^3$ respectively in the control area. Mean ratio of indoor to outdoor $NO_2$ concentration was 1.39. People spent 80.9% of their time in indoor at the study area and 76.9% at the control area. The percentages of time spent in outdoor were 14.9% and 20.9% at the study area and the control area respectively. The percentages of time spent in a car were 4.2% and 2.2% in the study and control areas respectively. The levels of indoor, outdoor, workplace nitrogen dioxide in the study area and the control area were found below the permissible level of health-hazardous effects.

• 한국자원식물학회지
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• 제5권1호
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• pp.57-68
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• 1992

The effects of various kind and amount of nitrogen fertilizers on the plant grorth. physiological , yield and extracts. ligustilide, butylidene phthalide contents of curdsdrug "Tou-ki" (AnTelica acutiloba Kitagawa) were investigated in 1989. Five plots variouskind of nitrogen fertilizers. Namely, no nitrogen, urea. ammonium nitrate, ammoniumchloride and control plot of ammonium sulfate. The other, by providing five plotsdifferent composed ratio of nitrogenous fertilizers. containing no nitrogen (No. o) .0.5-fold nitrogen (No s), control plot of 1.0-fold nitrogen(Nl.o). 1.5-fold nitrogen(Nl s)and 2.0-fold nitrogen Na. o), but nitogen was used the ammonium sulfate. The results showedthat the crude drug "Tou-ki" can ammonium chloride be produced in good yield, displayingboth good plant growth and remarkable physiologically-active conditions, and it can beproduced such that the extracts is maximized. Additionally, using methods of gaschromatography (GC) , it was established that ligustilide and butylidene phthalide, majorcomponents in the crude drug was recovered in a good yield from the fully grown plants.The other, the plant growth, the physiologically-active, the weight of whole plant, theyield of extracts and ligustilide, butylidene phthalide were seen to be best at the plotof 2.0-fold nitrogen and according to the increase or decrease of nitrogen decreasedgradually. Therefore. about 2 fold of standard quantity seems to be the most suitablequantity of nitrogen for "Tou-ki" cultivation .uot;Tou-ki" cultivation .ion .

• Asian-Australasian Journal of Animal Sciences
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• 제11권6호
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• pp.718-724
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• 1998

Twelve gilts were used to investigate the effect of lysine to protein ratio (5.2 g lysine/100 g CP vs. 6.7 g lysine/100 g CP) in practical diets on nitrogen retention and the efficiency of utilization in growing pigs. Treatments involved 2 levels of dietary lysine (5.2 or 6.7 g/100 g CP) and 3 levels of dietary crude protein (11, 14 and 17% in diet). Nitrogen retention was greatest when pigs were fed the control diet containing 17% protein. Nitrogen retention progressively increased as dietary protein increased (p < 0.01), but it was not affected by lysine concentration (g/100 g CP). Apparent biological value (ABV, nitrogen retained/apparently digestible nitrogen) was estimated to be ~50% at the maximum nitrogen retention. ABV was not affected by lysine concentration, but declined (p < 0.05) as the dietary protein level increased. The efficiency of intake N used for maximum nitrogen retention was approximately 44%. One gram of lysine supported approximately 9 to 10 g apparent protein accretion (nitrogen retention ${\times}$ 6.25/lysine intake) in pigs fed control diets. The efficiency of lysine utilization for protein accretion was lower in pigs fed high-lysine diets (6.7 g lysine/l00 g CP) so that 1 g of lysine accounted for 7 to 8 g of protein accretion in these pigs (p < 0.01). The lysine required to support maximum nitrogen retention in pigs fed high-lysine diets was higher than that in pigs fed control diets, which suggests that lysine was over-fortified relative to crude protein, since practical diets can not be formulated without excess of some amino acids. In summary the concentration of 5.2 g total lysine/100 g CP in diet is more appropriate for corn-soybean diets than the commonly suggested the content of 6.7 g total lysine/100 g CP.

• 한국토양비료학회지
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• 제42권4호
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• pp.301-306
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• 2009

이 연구의 목적은 건강한 작물과 시들은 식물의 질소대사와 아스코리빈산 함량의 차이를 비교하는것에 있다. 시듬은 인공적으로 유도되었으며, 그방은 질소과다 시비 및 저칼륨 시비에 의한 것으로4개의 처리구를 두었다. 1N-1P-1K (control), 6N-1P-0K (0K), 6N-1P-0.5K (0.5K), and 6N-1P-2K (2K). 시듬 정도는 control, 0%; 2K, 10%; 0.5K, 40%; and 0K, 70%. 식물 생장에는 고질소 저 칼륨 처리구에서는 그리 큰 차이가 없었으며 질산태질소의 함량은 control 구와 비교하여 고 질소 처리구가 높았으며, 아스코리빈 산 함량은 고질소 처리구가 control구에 비하여 낮았음을 확인 할수 있었다.

• 대한화학회지
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• 제35권6호
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• pp.659-666
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• 1991

질소를 함유한 흥분제와 마약성 진통제 18종류의 약물들을 gas chromatography-nitrogen phosphorus detector(GC-NPD)를 사용하여 human urine으로부터 동시에 신속하게 분석할 수 있는 최적조건을 찾기 위하여 pH 변화와 추출용매 변화에 따른 회수율을 조사하였다. pH 8.5에서 에테르를 추출용매로 사용하였을 때 가장 적은 방해영향과 가장 좋은 회수율을 나타냈다. NPD에 대한 각 약물들의 상대 감응인자를 구하였고, 이 상대감응인자는 약물이 가지고 있는 질소원자의 갯수가 증가할수록 작은 값을 나타냈다. 생체시료 중의 약물들을 신속하게 검정하기 위하여 내부표준물질인 diphenylamine에 대한 relative retention time(RRT)을 작성하였다. 상대머무름 시간은 0.1% 이하의 정밀도를 나타냈다.

• The Korean Journal of Ecology
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• 제26권2호
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• pp.71-74
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• 2003

Effects of nitrogen addition on the growth of Indigofera pseudo-tinctoria (Leguminosae) in the waste landfill site was investigated. Nitrogen fertilization in the nitrogen poor soils of waste landfill may influence the growth of nitrogen fixing plants beneficially or detrimentally. When I. pseudo-tinctoria was fertilized with three different levels of nitrogen, the coverage of plants treated with 46 g N/$m^2$ and 460 g N/$m^2$ was significantly less than that of plants treated with 23 g N/$m^2$. The growth rates of plant height treated with 46 g N/$m^2$ and 460 g N/$m^2$ were significantly less than those of plants treated with 23 g N/$m^2$. The growth rates of plant diameter treated with 46 g N/$m^2$ and 460 g N/$m^2$ were significantly less than those of plants treated with 23 g N/$m^2$. Dry weights of whole plants in control sites were higher than those of all the others nitrogen treatment sites. Nodule numbers were higher in control plants than those of plants in all the other nitrogen treatment sites. It is suggested that nitrogen fertilizer addition over 23 g N/$m^2$ affect the growth of some nitrogen fixing plants, such as I. pseudo-tinctoria, negatively.