• 한국유기농업학회지
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• 제26권3호
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• pp.463-475
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• 2018

국내 일부 시설재배지는 장기간 과도한 양분 투입 등에 의한 염류 집적 현상이 문제가 되어왔으며, 최근 이상기온에 따른 온도장해에 의한 피해도 발생하고 있다. 이러한 현상에 대해 친환경적으로 대처하기 위하여 고염류와 온도 스트레스에 대해 작물에 내성을 증강시키는 미생물을 선발하였다. 국내 토양에서 분리한 1,944균주중 고염류 또는 온도 스트레스 조건에서 세균의 생장과 식물생장촉진 관련 특성(IAA 생성, ACC deaminase 활성, 인산가용화능)을 고려하여 20균주를 1차 선발(전체 균주의 1.03%)하였다. 1차 선발한 20균주 중 토마토 식물검정을 통해 고염류 또는 온도스트레스에 대한 내성을 유도하는 7세균(1차 선발균주의 35%, 전체 균주의 0.36%)을 단계적으로 선발할 수 있었다. 선발된 세균은 16S rRNA 유전자의 염기서열 분석을 통해 모두 Bacillus 속에 속하는 것으로 확인되었다. 이러한 결과로 선발된 7균주는 토마토의 고염류 또는 온도 스트레스에 대한 효과적인 미생물 제제로 활용이 가능한 것을 확인할 수 있었다.

• 한국물환경학회지
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• 제25권1호
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• pp.48-57
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• 2009

A two-dimensional (2D), laterally-averaged hydrodynamic and water quality model, CE-QUAL-W2 was applied to evaluate the performance on simulating the effect of flushing from Daecheong Reservoir on the downstream water quality variations during the flushing events held on November, 2003 and March, 2008. The hydraulic and water quality simulation results were compared with field measurement data, as well as a one-dimensional (1D), unsteady model (KORIV1) that revealed limited capability in the previous study due to missing the resuspension process of river bottom sediments. The results showed that although the 2D model made satisfactory performance in reproducing the temporal variations of dissolved matters including phosphate, ammonia and nitrate, it revealed poor performance in simulating the increase of biological oxygen demand and suspended sediment (SS) concentrations during the passage of the flushing flow. The reason of the error was that the resuspension process of the 2D model is only the function of shear stress induced by wind. In reality, however, as shown by significant correlation between bottom shear stress ($\tau$) and observed SS concentration, the resuspension process can be significantly influenced by current velocity in the riverine system, especially during flushing event. The results indicate that the resuspension of river bottom materials should be incorporated into the water quality modeling processes if $\tau$ is greater than a critical shear stress (${\tau}_c$) for better simulation of flushing effect.

• 대한한의학회지
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• 제37권2호
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• pp.62-75
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• 2016

Objectives: This study examined whether Lycii Radicis Cortex has an inhibitory effect on inflammatory response through an oxidative stress and advanced glycation endproducts (AGEs)-mediated pathway in streptozotocin (STZ)-induced type 1 diabetic rats. Methods: Lycii Radicis Cortex was orally administered to STZ-induced diabetic rats in doses of 80 or 160 mg/kg body weight/day for 2 weeks, and its effects were compared with those of diabetic control and normal rats. Results: The administration of Lycii Radicis Cortex decreased the elevated serum urea nitrogen and renal reactive oxygen species (ROS), and reduced the increased AGEs in the serum and kidney. The elevated protein expressions of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase subunits in the kidney of diabetic control rats were significantly decreased after Lycii Radicis Cortex treatments. Moreover, the kidney of diabetic rats exhibited the up-regulation of receptor for AGEs (RAGE) and AGEs-related proteins; however, Lycii Radicis Cortex treatment also significantly reduced those expressions (excepted RAGE). In addition, the diabetic rats exhibited an up-regulation of the expression of proteins related to inflammation in the kidney, but Lycii Radicis Cortex administration reduced significantly the expression of the inflammatory proteins through the nuclear factor-kappa B (NF-${\kappa}B$) and activator protein-1 (AP-1) pathways. Conclusions: This study provides scientific evidence that Lycii Radicis Cortex exerts the antidiabetic effect by inhibiting the expressions of AGEs and NF-${\kappa}B$ in the STZ-induced diabetic rats.

• Preventive Nutrition and Food Science
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• 제15권4호
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• pp.267-274
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• 2010

We assessed the effect of Se-methylselenocysteine (MSC) treatment, at a dose of 0.75 mg/rat/day for 1 or 2 weeks, on the activities of antioxidant systems in Sprague-Dawley rat tissues. Significant changes in glutathione and antioxidant enzyme activities, with different patterns among tissues, were evidenced. Glutathione content and its reduction state in the liver, lung, and kidney were elevated upon MSC treatment, whereas they were significantly lowered in the spleen. Among the tissues exhibiting glutathione increase, there were different enzymatic responses: $\gamma$-glutamylcysteine ligase activity, the rate-limiting enzyme in the glutathione synthesis pathway, was increased in the liver, whereas the activities of the enzymes associated with glutathione recycling, namely, glutathione peroxidase, glutathione reductase, and glucose 6-phosphate dehydrogenase, were significantly increased in the lung and the kidney. The superoxide dismutase activity was decreased in all tissues upon MSC treatment, whereas catalase activity was increased in all tissues but the liver. Lipid peroxidation level was transiently increased at 1 week in the lung and the kidney, whereas it was persistently increased in the spleen. The increase was not evident in the liver. The results indicate that the MSC treatment results in an increase in the antioxidant capacity of the liver, lung, and kidney principally via an increase in glutathione content and reduction, which appeared to be a result of increased synthesis or recycling of glutathione via tissue-dependent adaptive response to oxidative stress triggered by MSC. The spleen appeared to be very sensitive to oxidative stress, and therefore, the adaptive response could not provide protection against oxidative damage.

• 한방비만학회지
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• 제19권1호
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• pp.1-11
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• 2019

Objectives: The purpose of the present study was to evaluate the preventive effects of ethanol extract of Polygalae radix (EEPR) against oxidative stress (hydrogen peroxide, $H_2O_2$)-induced DNA damage and apoptosis in Chang liver cells. Methods: Chang liver cells were pretreated with various concentrations of EEPR and then challenged with 0.5 mM $H_2O_2$. The cell viability and apoptosis were assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and flow cytometry analysis, respectively. The levels of reactive oxygen species (ROS), mitochondrial membrane potentials (MMPs) and adenosine tri-phosphate (ATP) contents were measured. Expression levels of Bcl-2 and Bax were also determined using Western blot analysis. Results: The results showed that the decreased survival rate induced by $H_2O_2$ could be attributed to the induction of DNA damage and apoptosis accompanied by the increased production of ROS, which was remarkably protected by EEPR. In addition, the loss of $H_2O_2$-induced MMPs and ATP contents was significantly attenuated in the presence of EEPR. The inhibitory effect of EEPR on $H_2O_2$-induced apoptosis was associated with up-regulation of Bcl-2 and down-regulation of Bax, thus reducing the Bax/Bcl-2 ratio. Conclusions: Our data prove that EEPR protects Chang liver cells against $H_2O_2$-induced DNA damage and apoptosis by scavenging ROS and thus suppressing the mitochondrial-dependent apoptosis pathway.

• Applied Biological Chemistry
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• 제40권1호
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• pp.48-52
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• 1997

다양한 가공 적성을 갖는 변성 전분을 토마토 케찹의 제조에 첨가하여 변성 전분의 종류 및 첨가량이 토마토 케찹의 유동 특성, 층분리 및 관능적 성질에 미치는 영향에 관하여 조사하였다. 케찹을 Herschel-Bulkley계 유체로 간주하여 분석한 결과 항복응력와 점조도지수는 ADA(acetylate distarch adipate)>SA(starch acetate)>HDP(hydroxypropyl distarch phosphate)>RCS(raw corn starch)>NS(no starch)의 순으로 크게 나타났으며 거동유동지수는 SA와 HDP의 경우 첨가량에 관계없이 거의 일정하였으나 ADA와 RCS는 첨가량이 증가할 수록 감소하는 경향을 보였다. 원심분리에 의한 층분리 검사에서는 ADA>SA>HDP>RCS>NS의 순으로 층분리가 방지되는 안정성을 나타냈다. 관능검사 결과 전반적으로 ADA(2%)>SA(2%)>RCS(2%)>NS>HDP(2%)의 순으로 기호도가 높게 나타났다.

• 한국토양비료학회지
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• 제49권1호
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• pp.17-29
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• 2016

Though there is an abundant supply of nitrogen in the atmosphere, it cannot be used directly by the biological systems since it has to be combined with the element hydrogen before their incorporation. This process of nitrogen fixation ($N_2$-fixation) may be accomplished either chemically or biologically. Between the two elements, biological nitrogen fixation (BNF) is a microbiological process that converts atmospheric di-nitrogen ($N_2$) into plant-usable form. In this review, the genetics and mechanism of nitrogen fixation including genes responsible for it, their types and role in BNF are discussed in detail. Nitrogen fixation in the different agricultural systems using different methods is discussed to understand the actual rather than the potential $N_2$-fixation procedure. The mechanism by which the diazotrophic bacteria improve plant growth apart from nitrogen fixation such as inhibition of plant ethylene synthesis, improvement of nutrient uptake, stress tolerance enhancement, solubilization of inorganic phosphate and mineralization of organic phosphate is also discussed. Role of diazotrophic bacteria in the enhancement of nitrogen fixation is also dealt with suitable examples. This mini review attempts to address the importance of diazotrophic bacteria in nitrogen fixation and plant growth improvement.

• 한국수산과학회지
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• 제27권6호
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• pp.690-695
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• 1994

혐기-호기 체계의 활성오니를 이용하여 폐수로부터 인과 질소를 동시에 제거하는 연구를 행하였다. 혐기적인 조건에서 nitrate 혹은 nitrite의 농도가 거의 0일 때, 제거된 glucose의 양은 orthophosphate의 방출과 직선적인 관계를 나타내었으며, 유입수에서 인과 glucose의 비율이 0.04 이하일 때, 폐수 중의 인은 호기적인 단계에서 거의 제거되었다. 이는 혐기적 단계에서 받은 stress로 인해 호기적 단계에서 받은 stress로 인해 호기적 단계에서 훨씬 많은 양의 인을 흡수한 것으로 생각된다. 혐기적 단계에서의 인의 방출양과 호기적 단계에서의 인의 흡수양은 $NO_x-N$의 농도와는 비례적인 관계가 아니었으며, 더우기, glucose에 대한 $NO_2-N$의 비가 0.37보다 낮을 때, 유입수 중의 무기질소는 완전히 제거되었다.

• Natural Product Sciences
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• 제17권2호
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• pp.117-122
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• 2011

We investigated the effect of Orostachys japonicus extracts on serum lipids, leptin and insulin level in hyperlipidemic rats. Also, diacylglycerol acyltransferase (DGAT) activity and thiobarbituric acid reactive substance (TBARS) were assessed. Inhibitory effect of DGAT related to triglyceride synthesis emerged approximately 96% in EtOAc fraction and showed 90% and 67%, respectively, in CHCl3 and BuOH fractions. Furthermore, the EtOAc and BuOH fractions inhibited 81% and 77%, respectively, in glycerol-3-phosphate acyl transferase (GPAT). Hyperlipidemia and obesity marker, contents of leptin and insulin on serum of hyperlipidemic rats, decreased 50% and 25%, respectively, compared with control group in treated EtOAc fraction. The oxidative stress marker, a concentration of TBARS, showed decrease of approximately 30% in treated EtOAc fraction. Moreover, high density lipoprotein (HDL)-cholesterol contents on serum of rats fed a hyperlipidemic diet were increased 10% and low density lipoprotein (LDL)-cholesterol decreased 50% as well as triglyceride amount of feces multiplied approximately two times more than control group in treated EtOAc fraction. The data suggest that the fractions of O. japonicus may be a potent biomaterial for treatment of hyperlipidemia or obesity.

• 한국자원식물학회지
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• 제19권5호
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• pp.612-616
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• 2006

최근 GMO 작물의 재배, 생산이 날로 늘어나며 GMO 작물이 환경에 미칠 수 있는 많은 가능성들이 대두되고 있다. 특히 GMO 작물과 야생종과의 자연교잡에 의한 유전자 전이로, 잡초화의 문제점이 제기되며 생태계의 변화 및 파괴의 위험성이 우려되고 있다. 본 실험에서는 GM벼와 야생 및 근연종 사이의 교잡가능성 및 유전자 전이율을 조사하기 위한 유전자 이동의 분석 체계를 확립하고자 하였다. 벼의 개화시기에 GM벼와 야생 및 근연종 간의 인공교배 후 수확한 교잡 추정 종자를 발아시켜서 제초제를 처리하여 교잡종자를 선별하였다. 또한 GM 벼 및 야생 근연종벼들 간의 RAPD PCR 분석을 통해 선별한 marker를 사용하여 낙동 교잡벼와 샤레 교잡벼가 GM 벼와 교배된 식물체임을 확인하였다. PCR 분석을 수행한 결과 GM벼에서 도입된 trehalose-6-phosphate phosphatase (TPP) 유전자와 선별marker로 사용된 bar유전자가 GM벼 뿐만 아니라 샤레 교잡벼에도 존재하였으며, 결과적으로 GM벼의 bar 및 tpp 유전자가 잡초성벼인 샤레 교잡벼에 전이되었음을 검증할 수 있었다.