• 생물환경조절학회지
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• 제15권1호
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• pp.84-90
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• 2006

This study was conducted to anticipate nitrate reduction state in tree through measurement of nitrate reductase activity (NRA) and investigate the effect of nitrogen concentrations (100, 200, 400, and 600 $mg\;L^{-1}$) on growth, the nitrogen content of various tissue, and NRA of pear (Pyrus pyrifolia cv. Niitaka) seedlings in sand culture. Nutrient solutions used in this experiment were adjusted to pH 6.5 and fixed the ratio of ammonium and nitrate to 1:3 and trickle-irrigated 3 times a day. Tree height and dry weight of various organs in seedlings were higher in low nitrogen concentration (100 and 200 $mg\;L^{-1}$) than in high nitrogen concentration (400 and 600 $mg\;L^{-1}$). The shoot growth in 600 $mg\;L^{-1}$ was extremely poor by nitrogen over supply. Increasing the nitrogen concentration, the concentration of nitrate-N in leaves and roots were insignificantly changed but that of stems increased. The accumulation of total and reduced nitrogen in all organs with increasing concentrations of nitrogen supply were increased at 30 days after treatment but those of all organs at 60 and 90 days after treatment were highest in 600 $mg\;L^{-1}$, whereas there were no significant changes among other nitrogen concentration. The in vivo (${+NO_3}^-$) NRA of all organs did not relate to nitrogen concentration but the in vivo (${-NO_3}^-$) NRA of leaves except roots increased with increasing the nitrogen concentration. Therefore, the proper nitrogen concentration to promote growth and nitrate reduction of pear tree was 200 $mg\;L^{-1}$.

• 한국습지학회지
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• 제13권3호
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• pp.489-497
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• 2011

본 연구의 목적은 인공습지를 이용하여 회야댐으로 유입되는 비점오염물질을 제어함으로써 수질을 향상시키는데 있다. 인공습지에 부들과 갈대를 식생하여 부영양화 유발물질인 질소(N)와 인(P)의 제거효율을 조사하였다. 또한, 인공습지 운영에 있어 계절적 및 수리하적 영향을 조사하였다. 인공습지에 의한 총 N와 P의 제거율은 평균적으로 20.7%와 42.7%로 나타났으며 계절적으로는 식생식물의 성장기(6월~7월)와 개화기(9월~11월)에 높은 제거 효율을 보였다. 이러한 결과로부터 인공습지는 회야댐으로 유입되는 비점오염물질인 N와 P을 효과적으로 제어하기 위한 대안으로 판단된다.

• 한국미생물·생명공학회지
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• 제28권3호
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• pp.161-166
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• 2000

Monilinia fructicola에 의해 감염되어 미이라화된 복숭아 열매로부터 Monilinia fructicola에 강한 항진균성 물질 chitinase 및 urease을 분비하는 방선균을 분리하였다 선발된 TH-04 균주는 배양적 .형태적 특성 세포벽 성분 및 세포내 당 성분을 분석한 결과 전형적인 Streptomyces속에 속하는 방선균으로 동정되었다. TH-04 균주는 Monilinia fructicola Colletotrichum gloeosporioides Magnaporthe grisea Rhizoctonia solani, Phytophthora capsici, Alternaria kikuchi-ana, Fusarium solani 및 Fusarium oxysporum 등 8종의 식물병원균에 대하여 항진균 활성을 나타냈다. 항생물질 생산을 위한 배양조건은 온도 $20^{\circ}C$, pH 7 및 배양기간 7일로 확인되었다.

• Journal of Nutrition and Health
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• 제38권1호
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• pp.67-75
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• 2005

This study was performed to examine the change of lipid metabolism and immune function caused by antioxidant material in hypercholesterolemic elderly women (serum total cholesterol $\geq$200 mg/dI). The subjects were 51 elderly women aged over 60 yrs. They were divided into antioxidant nutrients complex group (n = 25) and spirulina group (n= 26). Antioxidant nutrients complex (1 capsule/day) and spirulina (7.5 mg/day) were used for intervention for 8weeks. All the subjects were fully informed the purpose of study and gave written consents to participate in this study. Dietary intakes, anthropometric indices and blood assessment for lipid, immune function and antioxidant status were measured before and after supplementation. Either antioxidant nutrients complex or spirulina supplementation for 8weeks resulted in improved antioxidant status evidence by increased TAS (total antioxidant status) and decreased TB-ARS (thiobarbituric acid reactive substance) . This intervention led to decreased serum levels of total cholesterol, LDL-cholesterol, oxLDL, apolipoprotein B, IL-6 and IL-6 production by peripheral blood lymphocyte. In conclusion, the lipid profiles, immune function and antioxidant capacity were improved after either antioxidant nutrient complex or spirulina supplementation for hypercholesterolemic women. Therefore, improving antioxidant status using supplemen-tation could provide means of controlling cardiovascular disease in Korean elderly people.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2001년도 추계학술발표회
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• pp.75-78
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• 2001

Authors evaluated the feasibility of a permeable reactive biobarrier (PRB) treated with biofilm formed by Beijerinckia indica (B.indica). This study focused on evaluating two potentials of B.indica for the requirements of PRB: reducing the hydraulic conductivity and degrading the polycyclic aromatic hydrocarbons (PAHs). The hydraulic conductivity was estimated by rigid wall column test and finally the values were converted to the values of intrinsic permeability. The nutrient solution was passed through the biobarrier column to activate the bacterium and then leachate was in turn carried into the column to evaluate the durability of the biobarrier. Phenanthrene was selected as a representative substance of PAHs. The ability of degrading phenanthrene by B.indica was evaluated by two-phase partitioning bioreactor after estimating the possibility with two pretests: observing the colony formation and the optical density on glucose-free medium containing phenanthrene. With the results, B.indica produced large amount of strongly adhesive exopolysaccharides (EPS) and reduced several orders of magnitude of the hydraulic conductivity after 2 weeks of cultivation. Furthermore, about 1000mg/1 of phenanthrene could be degraded by B.indica in the two-phase partitioning bioreactor. In conclusion, the application of the bacterium, B.indica, was found to have a potential role of a PRB to retain and remove contaminants in porous media.

• The Plant Pathology Journal
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• 제23권3호
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• pp.161-165
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• 2007

Cultivation of a biocontrol agent on a certain medium often results in reduced biocontrol efficacy and alters physiological state. In our previous study, Burkholderia gladioli strain B543 with long-term subculture on tryptic soy agar resulted in significantly reduced biocontrol ability against cucumber damping-off caused by P. ultimum. Therefore, we investigated the influence of laboratory culturing media on biocontrol activity and physiological state of Burkholderia gladioli strain B543 by using long-term repeated culture on a certain medium. When isolate B543 were successionally cultured on King's B agar (KBA), tryptic soy agar, nutrient agar (NA), or soil extract agar more than 20 times, the isolate cultured on KBA or NA showed a significantly enhanced biocontrol efficacy and higher population density in the rhizosphere of cucumber compared to that of the others. However, the isolates cultured on KBA more than 20 times showed the lowest production of protease, siderophore, or antifungal substance(s), measured by skim milk agar, Chrome-Azurol-S agar, and potato dextrose agar amended with 10% of the culture filtrate, respectively. Our results suggest that adaptation to proper culturing medium can alter biocontrol ability and physiological state, and we must consider laboratory media in optimizing the use of biocontrol agents.

• 한국환경보건학회지
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• 제9권1호
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• pp.49-62
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• 1983

Evaluation of water quality of Yeong San river and Seomjin river by using of newly simplified MBOD method was performed. Of course, thought that there is some differences between nutrient demands of heterotrophic bacteria and those of Algae which obtain it by photosynthesis, but it has little influence on evaluation of Algae Growth potential. The result of this study were as follows: 1) In both river, the value of Chemical analysis and MBOD method of inorganic salts reveals as nearly same result. 2) Though organic pollution of Seomjin river is less than that of Yeongsan but inorganic contamination is somewhat advanced BOD 2.8 ppm. and MBOD 340 ppm. in Seomjin river but BOD 22 ppm. and MBOD 480 ppm. in Yeongsan river. 3) Both river have tendency to reveal higher Nitrogen value is MBOD=MBOD -P

• ALGAE
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• 제21권2호
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• pp.253-259
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• 2006

Organic substances are released from phytoplankton cells during all phases of growth. The type and amounts of organic substance excreted and the effects of nutrient limitation are often highly species-specific. Dinoflagellate, Cochlodinium polykrikoides grown in batch culture produced an exopolysaccharide. Exopolysaccharide and intracellular polysaccharide concentrations increased as C. polykrikoides cultures progressed from exponential phase, through stationary phase, to declining phase. In the exponential phase, the concentration of exopolysaccharide was relatively low, but in the stationary phase, it showed a rapid increase which seemed to coincide with the depletion of nitrate from the medium. Of the 20 amino acids analyzed, proline dominated in the organic matter of all cultures ranging from 48.2 to 79.9 nmol L–1, and constituting the 20-90% of total amino acids, and followed by histamine varying from 0.7 to 47.5 nmol L–1. Leucine and cysteine were also abundant in the stationary phase. The release rates of exopolysaccharide and intracellualr polysaccharide were higher the end of stationary phase than in the exponential phase. Exopolysaccharide concentration per cell was more than two times higher during the end of stationary phase than that in exponential phase. C. polykrikoides produced extracellular polysaccharide at a rate of 47.04 pg cell–1 day–1.

• Journal of Nutrition and Health
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• 제27권3호
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• pp.263-271
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• 1994

The concentrations of the immunological substances in breast milk and nutritional status were studied in healthy Korean women of middle socioeconomic class. The subjects were recruited at random from obstetric clinics in Seoul. The nutrients intake, prepregnancy BMI, maternal weight gain during pregnancy were studied. The concentrations of lactoferrin(LF), lysozyme(LZ), sIgA, IgG and C3 in colostrum, in transitional milk, and in mature milk, were measured. To elucidate the effect of nutritional status on immunological substances, each components was compared on the basis of either BMI, weight gain, or protein intake. The highest concentrations of the substances were found in colostrum and decreased as lactation progressed. The decline was more prominent in IgG, C3 and sIgA, and less significant in LZ and LF. The colostrum of standard weight gain group showed higher concentrations compared to lower weight gain group. This difference became smaller as the lactation progresses. BMI and nutrient intake status had less significant effect. Lower sIgA was found in lower BMI, in lower weight gain, and lower protein intake groups compared to standard groups, which indicates sIgA is the most affected substance among the measured by nutritional status.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• 제2권2호
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• pp.169-179
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• 1998

This paper was performed to estimate interrelations between humus level of sediments and nutrient release from sediments in Dae-cheong reservoir. For investigations, sediments were sampled in June and October, in 1997 at fish farms, embayment, and the main stream of Dae-cheong reservoir. Items for investigation are as follows; water content, weight loss on ignition(IG), porosities of sediments, contents of element such as hydrogen, nitrogen, carbon, and nutrient release rates. Water contents and porosities were measured to conjecture the physical trait and grain size trait. Weight loss on ignition was measured to determine the contents of organic substance. For determination of the humus level of sediments, carbon and nitrogen contents were measured by elemental analyzer. As a result of elemental analysis, C/N ratio was determined in the range of $3.0\~13.1$. From the elemental analysis, humus level of Dae-cheong reservoir sediment was estimated from mesohumic state to oligotrophic state. For the determination of nutrient release rate, $PO_4-P$ and $NH_4-N$ concentrations of interstitial water and overlying water were measured. By using the concentration difference between interstitial water and overlying water and using the Fick's diffusion law, the release rates of phosphorus and nitrogen from the sediment samples were calculated. Release rates of nutrients which directly influence to the water quality were $0.05\~8.63mgP/m^2day$ and $4.99\~36.56mgP/m^2day$. It was found that release rate was measured higher in the 1st sampling period than in the 2nd sampling period. For the determination of phosphorus content in sediment, TPs were measured in 807\~1542{\mu}g/g$ in the 1st samling period and $677\~5238{\mu}g/g$ in the End samling period. Phosphorus release rate and phosphorus content were not interrelated each other.