• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2004.10a
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• pp.137-141
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• 2004

본 연구는 우리나라에서 유통되고 있는 육제품의 잔류 아질산 함량 현황과 채소류의 아질산 함량을 조사하여 육제품 소비에 대한 안전성 평가 자료로 제시하고자 하였다. 분석한 21개 육제품의 아질산 함량 중 가장 높은 것은 40.3 ppm이었으며, 그 다음으로 39.61, 27.67, 22.36과 17.34 ppm 등이었다. 아질산 함량의 분포는 40 ppm 이상이 1 개 제품, 30-40 ppm이 1 개, 20-30 ppm이 2 개, 10-20 ppm이 6 개, 그리고 10 ppm 이하가 11 개 제품으로 절반 이상이 10 ppm 이하의 값을 보였으며, 그중 9 개 제품은 2 ppm 이하의 매우 낮은 아질산 함량을 보였다. 채소류의 아질산 함량은 전반적으로 매우 낮았으며, 그 중에서 아질산 함량이 가장 높은 것은 비트로 1.34 ppm 이었고 가장 낮은 것은 청경채로 0.04 ppm 이었다. 조리와 저장에 따른 시금치의 아질산 함량 변화를 살펴본 결과 데침 과정을 통하여 아질산 농도가 다소 감소하였으며, 생시금치의 경우 상온 저장은 냉장 저장과 달리 아질산 함량을 크게 증가시켰다.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.10
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• pp.1024-1030
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• 2006

Genus Nitrospira and Nitrobacter species are the key nitrite-oxidizing bacteria(NOB) in nitrifying wastewater treatment plants. It has been hypothesized that genus Nitrospira are K-strategists(low $K_6$ value) that can exploit low amounts of nitrite more efficiently than Nitrobacter. In contrast, Nitrobacter species are r-strategists(high $V_{max}$) that can grow faster than Nitrospira. It has also been known that the availability of organic compounds and dissolved oxygen as well as nitrite affects the distribution of NOB. In this study, we determined the distribution and competition of NOB in wastewater nitrification systems where nitrite, organic compounds, and dissolved oxygen concentrations were compositively varied. For the purpose, several compounds of the laboratory-scale nitrificaiion bioreactor and full-scale $A_2O$ wastewater treatment plant and their distribution of NOB were analyzed and compared. The analysis showed that Nitrobacter was the dominant NOB in nitrification bioreactor where average nitrite was maintained at 5 mg-N/L with very low organic concentration in aerobic condition, whereas Nitrospira was the dominant NOB in full-scale $A_2O$ plant where nitrite was maintained very low and organic compounds were maintained relatively high in alternating aerobic-anoxic condition. The result indicates that nitrite concentration is more critical factor than organics and dissolved oxygen which determines the dominant NOB in nitrification system and it is confirmed that Nitrospira and Nitrobacter showed the characteristics of r-strategist and K-strategist, respectively.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2004.10a
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• pp.402-406
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• 2004

신선야채를 섭취한 후 타액에 분비되는 아질산 함량 변화를 관찰하여 채소와 육제품 소비에 대한 안전성을 평가하는 자료로 제시하고자 하였다. 건강한 20-40대 성인 남녀를 대조군, 야채 제한섭취군, 자유섭취군 등의 3 군으로 나누어 하루동안 실험식이를 섭취하도록 한 후 타액의 아질산 농도를 측정하였다. 하루 동안 김치와 야채, 염지육제품 등 질산과 아질산 함유 식품을 섭취하지 않은 대조군의 경우 식전 타액의 아질산 농도는 1.93 ppm으로 매우 낮았으며, 식후 1 시간과 3 시간에도 각각 2.79 및 2.54 ppm으로 큰 변화가 없었다. 대조구와 같이 하루 동안 김치와 야채를 비롯한 질산과 아질산 함유 식품 섭취를 제한한 야채 제한섭취군도 식전 타액의 아질산 농도는 3.24 ppm으로 비교적 낮은 값을 보였으나 점심으로 야채 쌈밥을 섭취한 후 1 시간과 3 시간에는 28.3과 33.05 ppm으로 매우 높았다. 타액 채취 전 하루 동안 일상적인 식사를 자유롭게 섭취한 자유섭취군의 경우는 식전 타액 아질산 함량이 7.91 ppm으로 비교적 높은 값을 보였으며, 야채 쌈밥 식사 후 1 시간과 3 시간 후에는 21.51과 28.37 ppm으로 증가하였다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.4B
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• pp.427-432
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• 2006

The effects of free ammonia (FA) concentration and temperature on nitrite accumulation were studied. To estimate the most effective ammonium oxidation and nitrite build-up condition, nitrification tests were conducted in batch conditions at various FA concentrations, and at different ammonium concentration and temperature. The activation energies of ammonium oxidizer were 81.7 KJ/mol below $20^{\circ}C$, and 32.5 KJ/mol over $20^{\circ}C$, while that of nitrite oxidizer was 35.5 KJ/mol irrespective of temperature variations. The results of nitrification tests conducted at different FA concentrations and temperatures showed that temperature strongly affects nitrite accumulation, while effects due to FA concentrations were found negligible.

• Clean Technology
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• v.4 no.2
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• pp.23-31
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• 1998

Photo-sensitized oxidation of benzene in aqueous solution was conducted with persulfate, nitrate, nitrite, sulfate and chloride as sensitizers.In the photo-sensitized oxidation of benzene persulfate, nitrate and nitrite could act as sensitizers, while no detectable effects could be observed with sulfate and chloride. With increasing nitrite concentration the photo-sensitized oxidation of benzene ran through a maximum value and decreased thereafter with increasing nitrite concentration. A build-up of nitrite ions seemed to scavenge hydroxyl radicals. When nitrite was present with other ions, nitrite inhibited the photo-sensitized oxidation of benzene. Phenol and biphenyl were identified as intermediate.

• Journal of fish pathology
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• v.5 no.2
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• pp.93-118
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• 1992

The research was carried out to examine the chronic toxic effects of nitrite on the Japanese eel, Anguilla japonica by neans of histological observations. Young eel, 10.8g mean body weight. were exposed to 6 different concentrations of nitrite(1, 5, 10, 20, 30 and 40ppm) for 10 weeks. Each concentration was treated under 5 different levels of pH(5.5, 6.0, 6.5, 7.0 and 7.5) and each of these treatment was tested at 2 different temperature regimes($25^{\circ}C$ and $30^{\circ}C$). Proper concentration of nitrite was made by $NaNO_2$ and proper pH levels were made by the combinations of 0.1M $KH_2PO_4$ and 0.1M $NaHCO_3$. Histopathological test of gill tissues were made along with the test of the formation of thrombocystes and chloride cells on the gill filaments. At the lower pH levels, mucus secretion from the gill was incrased as the nitrite concentration increased. As the level of nitrite increased the number of chloride cells on the gill filament were decreased. Most of the remained chloride cells were observed only at the terminar part of the gill filament at 40ppm of nitrite. Degeneration of gill tissues were observed when nitrite levels were over 10ppm along with detachement and sweption of the epithelial cells of the gill lamellae. Shrunken gill lamellae and formation of thrombosis in the capillaries of gill lamellae were also observed. When temperature goes higher at the higher level of nitrite, necroses in the gill lamellae was increased. At the lower than 10ppm of nitrite, degeneration of gill lamellae was occured at the beginning of the test period but regenerated later. Negative effects of nitrite on the growth of young eel was started between 5~10ppm at the pH level of 7.0 and 7.5. Thrombosis formation were also started at this level. The safety concentration of nitrite at the pH levels of 7.0 and 7.5 on the small eel seems to be 1ppm. Thrombosis and gill lamella detachment and necrosis in the gill capillaries were not observed at this level. Chloride cells were appeared the whole part of the gill filament.

• ANNALS OF ANIMAL RESOURCE SCIENCES
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• v.30 no.2
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• pp.69-78
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• 2019

The objective of this study was to investigate the quality properties of sausages added with the atmospheric pressure plasma treated extract of Perilla frutescens Britton var. acuta Kudo (red perilla). The lyophilized powder of red perilla extract treated by atmospheric-pressure plasma contained 7.5 g kg^-1 nitrite. Sausage samples were manufactured with the addition of sodium nitrite (Control), celery powder (Celery), or plasma-treated extract of red perilla (PTP) to obtain nitrite concentration of 70 mg kg^-1. The residual nitrite content was the lowest in PTP during storage for 21 days at 4℃ (p<0.05). The total aerobic bacteria counts were higher in PTP than in Control and Celery during storage at 4℃ (p<0.05). Malondialdehyde content of sausages was significantly lower in PTP than in Control and Celery during storage (p<0.05). PTP showed the lowest L^* value and the highest b^* value among the tested sausage samples during storage (p<0.05). PTP received the low scores in all the sensory properties of sausages because of its inherent color and flavor. The results suggested that the plasma-treated extract of red perilla was an unsuitable natural nitrite source for cured meat products because of its adverse effect on sensory quality. However, natural nitrite source with increased nitrite content can be produced by the treatment of the natural plant extract with atmospheric-pressure plasma.

• Korean Chemical Engineering Research
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• v.44 no.2
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• pp.200-206
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• 2006

In a biological aerated filter (BAF) packed with ceramic media (void fraction of BAF=0.32), nitrite accumulation was studied with the variation of hydraulic retention time (HRT) and superficial air velocity. Synthetic ammonium wastewater and petrochemical wastewater were fed at a constant load of $1.6kgNH_4^+-N/m^3{\cdot}d$. Ammonium removal rate was mainly affected by the superficial air velocity in BAF, but nitrite ratio($NO_2-N/NO_x-N$) in the effluent was dependent on both HRT and superficial air velocity. For a fixed HRT of 0.23 hr (corresponding to the empty bed contact time of 0.7 hr) ammonium removal rate was 73/90/92％ and nitrite ratio was 0.92/0.82/0.48 at the superficial air velocity of 0.23/0.45/0.56 cm/s, respectively. When HRT is increased to 0.9 hr with superficial air velocity ranging from 0.34 to 0.45 cm/s, the ammonium removal rate was 89％ on average. However nitrite ratio decreased significantly down to 0.13. When HRT was further increased to 1.4 hr, ammonium removal rate decreased, thereby resulting in the free ammonia ($NH_3-N$, FA) build-up and nitrite ratio gradually increased (>0.95). Although aeration rate and FA concentration at HRT of 0.23 hr were unfavorable for nitrite accumulation compared with those at HRT of 0.9 hr, nitrite ratio at HRT of 0.23 hr was higher. Taken together, HRT and nitrogen load were found to be critical, in addition to FA concentration and aeration condition, for nitrite accumulation in the BAF tested in the present study.

• Journal of Plant Biotechnology
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• v.48 no.3
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• pp.124-130
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• 2021

Nitrate is an important nutrient and signaling molecule in plants that modulates the expression of many genes and regulates plant growth. In this study, we cover the research status of transcription factors related to the control of gene expression by nitrate signaling in higher plants. Nitrate reductase is a key enzyme in nitrogen assimilation, as it catalyzes the nitrate-to-nitrite reduction process in plants. A variety of factors, including nitrate, light, metabolites, phytohormones, low temperature, and drought, modulate the expression levels of nitrate reductase genes and nitrate reductase activity, which is consistent with the physiological role if. Recently, several transcription factors controlling the expression of nitrate reductase genes have been identified in higher plants. NODULE-INCEPTION-Like Proteins (NLPs) are transcription factors responsible for the nitrate-inducible expression of nitrate reductase genes. Since NLPs also control the nitrate-inducible expression of genes encoding the nitrate transporter, nitrite transporter, and nitrite reductase, the expression levels of nitrate reduction pathway-associated genes are coordinately modulated by NLPs in response to nitrate. Understanding the function of nitrate in plants will be useful to create crops with low nitrogen use.

• Clean Technology
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• v.4 no.2
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• pp.11-22
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• 1998

The photo-sensitized oxidation of benzene in water was investigated under various reaction conditions using persulfate, sulfate, nitrate, nitrite and chloride ions as sensitizers. Persulfate ion was proved to be the most effective sensitizer, while sulfate and nitrite could not play any sensitizing role on the benzene photooxidation. When exited together with other ions, the nitrite ion inhibited the photooxidation of benzene by quenching the produced hydroxyl radicals.