• 한국식품영양과학회지
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• 제26권4호
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• pp.556-562
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• 1997

여러 온도 조건에서 김치에서 분리된 유산균에 의하여 아질산염을 소모하는 정도와 이들 분리균에 의하여 성장온도와 배지의 pH에 따른 아질산염 소모의 영향을 검토하였다. 15와 2$0^{\circ}C$에서 L. plantarum과 L. sake는 성장 초기에 아질산염 소모 활성이 낮았으나 성장기간과 온도에 따라 활성이 높았고, $25^{\circ}C$와 3$0^{\circ}C$에서는 L. plantarum은 성장 1일 부터 90% 이상, L. sake는 아질산염을 75% 이상 소모하였으며, 성장 2일 이후에는 거의 대부분을 소모하였다. L. mesenteroides는 15와 2$0^{\circ}C$에서는 성장 4일이 경과한 후에 150과 250$\mu\textrm{g}$/$m\ell$의 아질산염에 대한 소모율이 각각 75와 65% 이하로서 Lactobacillus에 비하여 소모 활성 이 낮았으나, 성장 4일이 경과한 후 $25^{\circ}C$에서는 83% 이상, 3$0^{\circ}C$에서는 98% 이상을 소모하였다. 한편, L. plantarum은 600과 900$\mu\textrm{g}$/$m\ell$의 고농도의 아질산염에 대해서도 성장 2일만에 거의 대부분을 소모하였다. 모든 김치 분리 유산균은 성장 온도와 배양 기간에 따라 배지의 pH가 낮아졌으며, 또한 배지의 pH가 낮아짐에 따라 아질산염 소모율이 증가하였다. 15와 2$0^{\circ}C$에서는 배지의 pH가 아질산염의 감소와 관련이 없었으나, $25^{\circ}C$이상에서는 직접적인 관련이 있어서, pH의 감소가 어느 정도 아질산염 소모에 관여하기는 하였지만, pH보다는 온도의 영향이 더 컸다.

• 한국미생물·생명공학회지
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• 제28권1호
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• pp.39-44
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• 2000

This study was carried out to develop a new starter culture for the fermented meat products. Nine strains of lactic acid bacteria isolated from kimchi inhibited the growth of Listeria monocytogenes. Among these nine strains, three strains showing antimicrobial activities against Escherichia coil, Staphylococcus aureus and Vibrio paraphaemolyticus were selected for further study. Growth of the strains was inhibited in MRS broth containing 5% of NaCl at $21^{\circ}C$, but not at $32^{\circ}C$. Nitrite depletion ratio of the strains was above 70% after 48h incubation at $21^{\circ}C$, and above 90% after 48h at $32^{\circ}C$ in MRS broth containing $200\mu$g/ml of nitrite, Nitrite concentration of cured meats and ground meats was depleted from 87.6% to 92.3% and from 45.5 to 640.6% by addition of the selected strains for 24h at $32^{\circ}C$, respectively. Three strains were identified as Lactobacillus plantarum(N4) and Lactobacillus lactis ssp. lactis(N-7, an-8).

• 한국식품영양과학회지
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• 제26권4호
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• pp.549-555
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• 1997

김치로부터 20종의 유산균을 분리하여 이들 중 6종은 Lactobacillus sake, 10종은 Leuconostocmesente-roides, 4종은 Lactobaillus plantarum으로 동정되었다. 이들 균주에 의하여 MRS 액체배지에 최종 농도가 250$\mu\textrm{g}$/$m\ell$가 되도록 첨가한 아질산염을 소모시키는 능 력을 시험한 결과 아질산염 소모율은 시험된 모든 온도 조건에서 L. plantarum, L. sake, L. mesenteroides 순서로, 성장 온도가 상승함에 따라 높았다. 특히 공시 L. Plantarum은 시험 된 모든 온도 조건에서 성장하는 중에 대부분의 아질산염을 소모시켰다. 그러나 온도에 대 한 적응성에 기인하여 L. plantarum은 15와 2$0^{\circ}C$에서 2일과 1일의 유도기간을 요하였으며, L. sake는 15$^{\circ}C$와 2$0^{\circ}C$에서 모두 1일의 유도기간을 요하였다. 반면 L. mesenteroides는 시험된 모든 온도 영역에서 유도기간을 요구하지 않았다.

• 한국식품영양과학회지
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• 제38권7호
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• pp.892-901
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• 2009

본 연구는 시판 배추김치, 총각김치, 깍두기 및 파김치에서 분리한 젖산균을 $15^{\circ}C$와 $25^{\circ}C$의 온도에서 배양하였을 때 아질산염의 소거 효능을 확인하였다. $15^{\circ}C$에서, 시판김치에서 분리된 젖산균은 L. mesenteroides subsp mesenteroides와 L. paramesenteroides를 제외하고는 매우 활성적으로 아질산염을 소거시켰다. 특히 L. mesenteroides subsp dextrinicum과 L. lactis는 아질산염에 적응하는 기간을 필요로 함이 없이 매우 활성적으로 아질산염을 소거시켰다. L. sake, L. plantarum, L. casei subsp. pseudoplantarum 및 L. coryniformis subsp. torquens는 하루 정도 아질산염에 적응하는 기간을 거친 이후에 매우 활성적으로 아질산염을 소거시켰다. L mesenteroides subsp. mesenteroides는 하루가 경과된 이후에 비교적 활성적으로 아질산염을 소거시켰다. 그러나 L. mesenteroides subsp. mesenteroides는 다른 균종에 비하여 매우 낮은 아질산염 소거율을 나타내었다. $25^{\circ}C$에서, 시판김치에서 분리된 모든 젖산균은 아질산염에 적응하는 기간을 필요로 하지 않았으며, L. paramesenteroides를 제외하고는 매우 활성적으로 아질산염을 소거하였다. 또한 시판김치로부터 분리된 젖산균은 L. mesenteroides subsp. mesenteroides와 L. paramesenteroides를 제외하고는 1일 이후에, L. mesenteroides subsp. mesenteroides는 2일 이후에 90% 이상의 아질산염을 소거시켰다. 그러나 L. paramesenteroides는 $25^{\circ}C$에서도 활성적이지 못하여 다른 균종에 비하여 아질산염의 소거 능력이 매우 낮았다. 한편, 다른 김치 기원의 동일 균종의 Lactobacilli와 L. mesenteroides subsp. mesenteroides 및 L. paramesenteroides를 제외한 Leuconostocs는 $15^{\circ}C$에서는 물론 $25^{\circ}C$에서 매우 활성적으로 아질산염을 소거시켰다.

• 대한수의학회지
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• 제40권2호
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• pp.267-274
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• 2000

Since intracellular free $Mg^{2+}$ ($[Mg^{2+}]_i$) appears to be tightly regulated following cellular energy depletion, we hypothesized that the increase in $[Mg^{2+}]_i$ would result in $Mg^{2+}$ extrusion into circulation. Extracellualr $Mg^{2+}$ contents ($[Mg^{2+}]_o$) were measured in rat erythrocytes, the perfused heart and liver, and plasma in the anesthetized rat. Animals were injected intraperitoneally with sodium nitrite ($NaNO_2$) and plasma $Mg^{2+}$ was measured after the injection and then 10 and 20 minutes later. An increase in circulating (plasma) $Mg^{2+}$ ($[Mg^{2+}]_c$) and methemoglobin was observed in animals injected with $NaNO_2$ (30 mg/Kg). The time course of the effects demonstrated that $[Mg^{2+}]_c$ and methemoglobin continued to increase 10 minutes after the $NaNO_2$ injection. Under these conditions, there was a sustained increase in $[Mg^{2+}]_c$, but not in methemoglobin, which was inhibited by pretreatment with potassium cyanide (KCN, 4 mg/Kg), indicating that an increase in $[Mg^{2+}]_c$ was accompanied by ATP depletion. Injection of rotenone (0.9 mg/Kg) or 2,4-dinitrophenol (15 mg/Kg) also induced an increase in $[Mg^{2+}]_c$. Reduced respiration rate from 100/min to 10/min during 30 minutes also caused a time-dependent rise in $[Mg^{2+}]_c$. These increase in $[Mg^{2+}]_c$ were inhibited by pretreatment with KCN. In addition, ATP depletion by $NaNO_2$ or KCN sustainedly increased the $[Mg^{2+}]_o$ in rat erythrocytes. $Mg^{2+}$ efflux was stimulated by KCN in the perfused heart and liver, but not by $NaNO_2$. These results suggest that the activation of $Mg^{2+}$ effluxes into the circulation is directly dependent on the ATP depletion-induced increase in $[Mg^{2+}]_i$ and heart, liver and erythrocytes have a major pool of $Mg^{2+}$ that can be mobilized upon cellular energy state.

• 유기물자원화
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• 제8권2호
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• pp.146-153
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• 2000

우분에 사과박을 혼합해 만든 퇴비화에서의 세균군집 특히, 질화세균의 천이를 rRNA targeted oligonucleotide probes을 사용하는 FISH(fluorescent in situ hybridization)법으로 규명하였다. 암모니아산화 세균수는 $3,3{\sim}13.4{\times}10^6cells/g$ dw의 범위에서 변화하였으며 퇴비화 26일 후에 그 최고치를 나타냈다. 반면에 아질산 산화세균은 $6.0{\sim}17.2{\times}10^6cells/g$ dw의 범위에서 변화하면서 퇴비화 7일 후에 그 최고치를 보였다. 암모니아산화세균수가 아질산산화세균수 보다 크게 나타나는 경향과 최고치를 나타내는 시점이 이들 세균군의 진정세균에 대한 비율을 측정했을 때에도 동일하였다. 암모니아산화 세균수가 아질산산화세균수보다 늦게 늦게 그 최고치를 나타내는 것은 휘발성의 암모니아가스가 퇴비화과정 초기에 고갈되었기 때문일 가능성이 크다. 아울러 본 연구결과는 FISH법이 생장이 더딘 질화세균의 검출에 유용한 도구임을 시사해 준다.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제11권sup1호
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• pp.83-92
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• 2008

Helicobacter pylori is the causative agent of chronic gastritis and has a role in the pathogenesis of peptic ulcer diseases, and gastric cancer. There have been reports suggesting a close link between these gastroduodenal disorders and a state of vitamin C deficiency. In this paper, the past, present and future perspectives on H. pylori infection and vitamin C will be discussed under the following view points. Since the ecological niche of H. pylori is the mucus layer and intercellular junctions of the gastric epithelium, the various kinds of host inflammatory cells motivated by the local and systemic immune responses cannot eliminate the microorganisms. When the invading foreign body is not removed, despite full activation of defense mechanisms, adverse consequences of the immune responses develop on the host gastric mucosa. The reasons for the body vitamin C depletion could be explained as follows; 1) the increased vitamin C consumption by increased oxygen free radical production through the prolonged hypersensitivity reactions in the gastric mucosa, 2) the increased vitamin C oxidation by the nitrite which is formed from nitrate reduction by the intragastric bacteria proliferated in the hypochlorhydric gastric cavity, 3) the strong ${\gamma}$-glutamyltranspeptidase activity of H. pylori which depletes the glutathiones in gastric mucosa. Depletion of glutathiones in the stomach favors irreversible oxidative destruction of ascorbic acid. Both persistent inflammatory burdens in the stomach by H. pylori and resultant vitamin C depletions synergistically and uninhibitedly might aggravate the hypothetical sequence of gastric carcinogenesis: atrophic gastritis${\rightarrow}$intestinal metaplasia${\rightarrow}$dysplasia${\rightarrow}$gastric adenocarcinoma. High intake of vitamin C could reverse the hypothetical sequence of the gastric carcinogenesis via direct and indirect effects on H. pylori and host-parasite relationships.

• 한국환경농학회지
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• 제24권3호
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• pp.245-252
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• 2005

The objective of the present work was to determine the corresponding uptake and assimilation of ${NO_3}^-$ in roots and shoots of leafy radish by applying of mixed amino acids (MAA). The amino acids used in this experiment were alanine (Ala), ${\beta}-alanine\;({\beta}-Ala)$, aspartic acid (Asp), asparagines (Asn), glutamic acid (Glu), glutamine (Gln), and glycine (Gly). Leafy radish was grown by conventional fertilization with macro- and micronutrients under controlled conditions. The 15-day-old seedlings were treated 0, 0.3 and 3.0 mM of MAA containing 5 mM ${NO_3}^-$ in growth medium. Nitrate uptake was determined by following ${NO_3}^-$ depletion from the uptake solution. The activity of the enzymes related to the process of ${NO_3}^-$ reduction (NR: nitrate reductase; NiR: nitrite reductase; GS: glutamine synthetase) and the content of ${NO_2}^-\;and\;{ND_3}^-$ were analyzed in shoots and roots. The results of this study showed that ${NO_3}^-$ uptake was inhibited 38% with treatment of 0.3 mM of MAA. However, there was more than three times increase of N03- uptake in 3.0 mM MAA. In addition, the enzymatic activities were positively affected by the high MAA rate. Finally, the ${NO_3}^-$ content was increased slightly both in shoots and roots of leafy radish by MAA treatments.

• Environmental Engineering Research
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• 제10권5호
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• pp.227-238
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• 2005

The characteristics of nitrogen removal by the free cell and the immobilized cell of R. capsulatus were investigated. Denitrification by R. capsulatus cells resulted in reduction of ORP with the rapid depletion of DO and the increase of pH. Without accumulation of nitrite, the removal efficiencies of ${NO_3}^-$-N for the free cell and the immobilized cell were 99.1 and 99.3%, respectively. During the three-month experiment of goldfish breeding equipped with a water-purification biofilter, the average values of pH and total cell numbers present in an aquarium were not significantly different between water-purification system and the control. The average concentrations of ${NH_4}^+$-N and ${PO_4}^{2-}$-P in water-purification system were relatively low, compared to that in the control. Goldfish died at $11^{th}$, $16^{th}$, $43^{rd}$, and $67^{th}$ days in the control, while goldfish died at $10^{th}$, $20^{th}$, and $39^{th}$ days in the water-purification system. On the days of goldfish's death, the total concentrations of nitrogenous compounds except for ${NO_2}^--N$ were higher than those on the other days of the experiment, especially with the concentrations of ${NH_4}^+$-N ranging from 7.4 to 13.5 mg/L. The water-purification system also showed the less turbidity of water with more active movement of goldfish than the control. PVA gel beads showed almost the full denitrifying ability even after the long-term experiment. As a result, the water-purification system was effective to remove nitrogenous compounds with better survival of goldfish.

• 한국환경보건학회지
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• 제44권3호
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• pp.259-266
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• 2018

Objectives: Considered the "national fish" in Korea, the walleye pollock (Gadus chalcogrammus) has disappeared in the East Sea (Sea of Japan), a main habitat and fishing ground for the species. The reason for the disappearance is still a matter of controversy. This study was performed to investigate the long-term relationship between the walleye pollock catch and various meteorological and oceanographic factors in these waters. Methods: Fishery data on walleye pollock and data on meteorological and marine environmental factors over the 30 years (1981-2010) were obtained from the official national database. Time series analysis and correlation and regression analyses were performed to study the relationships. Results: Both air temperature and sea surface temperature in the East Sea rose over these 30 years, and the latter became more prominent. Salinity and dissolved oxygen showed a tendency to decrease while concentrations of nutrients such as nitrite nitrogen and nitrate nitrogen showed an increasing tendency. Sea surface temperature, air temperature, atmospheric pressure, and wind grade were negatively correlated with the catch size of walleye pollock (p<0.05), but salinity was positively correlated (p<0.001). Conclusion: The results of this study indicate that climate change, especially ocean warming, affected the habitat of walleye pollock. The results also indicate that lower sea surface and air temperatures, milder wind grade, and higher salinity were preferred for the survival of the fish species. It is necessary to pay attention to changes of the ocean ecosystem in terms of environmental pollution as well as seawater temperature.