• Asian-Australasian Journal of Animal Sciences
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• 제31권8호
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• pp.1073-1077
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• 2018

Nitrite plays a major role in inhibiting the growth of foodborne pathogens, including Clostridium botulinum (C. botulinum) that causes botulism, a life-threatening disease. Nitrite serves as a color-fixing agent in processed meat products. However, N-nitroso compounds can be produced from nitrite, which are considered as carcinogens. Thus, consumers desire processed meat products that contain lower concentrations (below conventional concentrations of products) of nitrite or no nitrite at all, although the portion of nitrite intake by processed meat consumption in total nitrite intake is very low. However, lower nitrite levels might expose consumers to risk of botulism poisoning due to C. botulinum or illness caused by other foodborne pathogens. Hence, lower nitrite concentrations in combination with other factors such as low pH, high sodium chloride level, and others have been recommended to decrease the risk of food poisoning. In addition, natural compounds that can inhibit bacterial growth and function as color-fixing agents have been developed to replace nitrite in processed meat products. However, their antibotulinal effects have not been fully clarified. Therefore, to have processed meat products with lower nitrite concentrations, low pH, high sodium chloride concentration, and others should also be applied together. Before using natural compounds as replacement of nitrite, their antibotulinal activities should be examined.

• Advances in Traditional Medicine
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• 제5권3호
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• pp.209-215
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• 2005

This study was conducted to investigate the efficacy of antioxidative activity and nitrite scavenging ability of each fractions from Phyllostachys bambusoides S. et Z. (P. bambusoides) trunk ethanolic extract using reverse-phase flash chromatography. Among the each fractions, fraction 3 $(H_2O\;:\;MeOH\;=\;1:1)$ showed high DPPH free radical scavenging activity (81.33%) at $80\;{\mu}g/mL$ concentrations and strongly inhibited autooxidation of pyrogallol by superoxide dismutase-like activity (45.8 %) at 0.46 mg/mL concentrations compared with different fractions. The fraction 3 was also increased to 76.62% cell viability against hydrogen peroxide-mediated cytotoxicity. Nitrite scavenging ability was the most remarkable under pH 1.2 condition among various pH regions examined and effectively exhibited to 65.6% by treatment of the fraction 3 with a concentration of 0.2 mg/ml. In general, nitrite scavenging ability decreased with higher pH condition. These results suggest that fraction 3 from P. bambusoides ethanolic extract can be used for bioacitve and functional materials.

• 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.

• Journal of Microbiology and Biotechnology
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• 제25권12호
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• pp.2116-2124
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• 2015

To understand the effects of physicochemical factors on nitrite transformation by microalgae, a lipid-rich Chlorella with high nitrite tolerance was cultured with 8 mmol/l sodium nitrite as sole nitrogen source under different conditions. The results showed that nitrite transformation was mainly dependent on the metabolic activities of algal cells rather than oxidation of nitrite by dissolved oxygen. Light intensity, temperature, pH, NaHCO₃ concentrations, and initial cell densities had significant effects on the rate of nitrite transformation. Single-factor experiments revealed that the optimum conditions for nitrite transformation were light intensity: 300 μmol/m²/s; temperature: 30℃ pH: 7-8; NaHCO₃ concentration: 2.0 g/l; and initial cell density: 0.15 g/l; and the highest nitrite transformation rate of 1.36 mmol/l/d was achieved. There was a positive correlation between nitrite transformation rate and the growth of Chlorella. The relationship between nitrite transformation rate (mg/l/d) and biomass productivity (g/l/d) could be described by the regression equation y = 61.3x (R² = 0.9665), meaning that 61.3 mg N element was assimilated by 1.0 g dry biomass on average, which indicated that the nitrite transformation is a process of consuming nitrite as nitrogen source by Chlorella. The results demonstrated that the Chlorella suspension was able to assimilate nitrite efficiently, which implied the feasibility of using flue gas for mass production of Chlorella without preliminary removal of NO_X.

• 한국물환경학회지
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• 제18권3호
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• pp.283-290
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• 2002

In this study, home-made detection system by means of noble FIA is introduced on the measurement of toxic nitrite in the water samples collected from the area of Kwangju. As the standard calibration between 30 to 1000 ppb, the linearity has been shown more than 0.9999 as the correlation coefficient($R^2$) with the detection limit 1.5 ppb(S/N>2). The distribution of sample concentration was monitored as N.D. - 123 ppb which is wide span of concentrations in field water samples. The low level of nitrite is hardly detectable with other expensive sophisticated instruments including ion chromatography. Whereas the result of high concentration brings forth the necessity monitoring constantly our precious water resources. Successfully, the FIA system has played a very important role detecting wide span of nitrite in water sample. This technique can be adopted for controlling our environment in the near future.

• 상하수도학회지
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• 제19권4호
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• pp.446-454
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• 2005

An economic treatment method to remove oxidized nitrogen from wastewater is biological denitrification with organic matters. Several organics can be used, however, methanol is commonly used. When methanol is provided, M:N (Methanol to Nitrogen) ratio is used to define methanol demand for denitrification. In this study, two artificial wastewaters were provided to a biological system to evaluate denitrification performance. Differences of influent total CODcr from effluent soluble CODcr were converted to methanol equivalent and oxidized nitrogen difference between influent and effluent were converted to nitrate equivalent to define M:N ratios. Modes I, II, III, I-1 and IV showed 5.1, 2.7, 3.3, 2.3 and 2.6 of M:N ratios, respectively. Since denitrifying microorganisms had to build a new metabolic system for methanol and influent organics, initial operation mode, Mode I, required more methanol and this resulted in high M:N ratios compared with later operation mode, Mode I-1. Salt in influent did not show inhibitory effects on denitrfication, although this was believed to increase effluent SS and soluble CODcr concentrations in Mode III, I-1 and IV, respectively. The concentrations of effluent soluble $COD_{Mn}$ did not changed much with influent salt.

• 한국식품영양과학회지
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• 제33권4호
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• pp.621-625
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• 2004

청미래덩굴잎의 ethanol 추출물로부터 얻은 용매별 각 분획물의 전자공여능, 아질산염소거능 그리고 항균활성을 측정한 결과 다음과 같다. 각 용매별 분획의 수율은 극성이 높은 수용성 분획과 methanol분획이 각각 63.73%와 26.40%로 높게 나타났다. 전자공여능은 ethyl acetate 분획에서 가장 높게 나타났으며 10분간 반응시켰을 때 약 81%정도 달했다. 반면 chloroform분획에서는 약 26%로 가장 낮았다. 아질산 염소거능은 ethyl acetate와 butanol분획에서 가장 높게 나타났다. 항균활성은 모든 분획의 2.5%와 5.0%의 농도에서 Gram(+)균인 Listeria monocytogenes와 Staphylococcus aureus에 대해 항균작용이 나타났으나 2.5%농도에서는 Gram (-)균인 Escherichia coli O157:H7과 Salmonella Typhimurium에 대해서는 전혀 활성이 없었으며 5.0%농도에서는 ethanol 추출물, ethyl acetate와 물분획에서 아주 낮은 활성이 측정되었다.

• 한국물환경학회지
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• 제27권6호
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• pp.769-775
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• 2011

An experimental study of biofilm nitritation system for high-strength ammonium wastewater has been carried out to examine the temperature effect on different organic and solid concentration. Operating temperature varied from $35^{\circ}C$ to $15^{\circ}C$. The influent N concentration of identical three reactors was adjusted to about $300mg\;NH_4-N/L$. A control unit fed with a synthetic wastewater, while the others were fed with reject water which is consisted of the supernatant of both digester and thickener. The results indicated that nitrite accumulation was stable in temperature range of $35^{\circ}C$ to $25^{\circ}C$. However, nitritation was significantly reduced at below $20^{\circ}C$. Free ammonia (FA) and free nitrous acid (FNA) were major inhibitors to the nitrite oxidizer for nitrite accumulation in lower temperature. From the estimation of temperature coefficient (${\Theta}$) of biofilm and suspended nitritation system, biofilm nitritation system could absorb the negative temperature effect compared with suspended nitritation system.

• 환경위생공학
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• 제10권3호
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• pp.56-66
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• 1995

To investigate environmental impacts of inland fish- farms on the water quality of a stream, environmental parameters including physical, chemical and biological factorswere estimated at trount- farm in 1994. Influences( F-1) were polluted as passing through fish tank( F-2) and settle pond( F-3), so organic and inorganic nutrient concentrations became very high in effluents( F-4). BOD$_{5}$, Chl. a, Nitrite and heterotrophic bacterial numbers in the junction site(5-2) of F-4 and S-1( upstream) were highest among the stream sites. BOD$_{5}$ was proved to a good parameter of organic pollution, and nitrite of Inorganic nutrients in the fishery and it's affected stream, The high concentration of BOD$_{5}$ and Chl. a in S-2 were decreased in downstream(5-3, 5-4). It seems that this results are due to dilution or sedimentation effect. This supposition requires further testing about the sediment of stream. The results of this paper demonstrate that fish farming can deteriorate water quality of a stream by changing environmental factors.

• Journal of Microbiology and Biotechnology
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• 제18권8호
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• pp.1470-1474
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• 2008

Nitrospira is a dominant member of nitrite-oxidizing bacteria (NOB) in nitrifying bioreactors as well as in natural habitats. In this study, Nitrospira NOB were investigated in the two nitrifying reactors operated with high and low dissolved oxygen (DO) concentrations for a period of 300 days. Phylogenetic and terminal restriction fragment length polymorphism analyses based on 168 rRNA gene sequences revealed that the Nitrospira community compositions of the two reactors during the early period related to group 1 and half of the Nitrospira community composition shifted to group 2 in the high-DO reactor after day 179, although there was no significant change in the low-DO reactor. These results suggested that DO was an important factor affecting Nitrospira community compositions in the nitrifying reactors.