• Ocean and Polar Research
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• 제32권1호
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• pp.63-71
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• 2010

An experiment was conducted to investigate the effects of temperature and stocking density on daily patterns and rates of total ammonia nitrogen (TAN) excretion in juvenile red seabream Pagrus major (mean body weight: 29.0 g) under fasting and feeding conditions. Fish were acclimated over 7 days under four different temperatures (10, 15, 20, and $25^{\circ}C$) and at two different densities (5.5 and $11.0\;kg\;m^{-3}$). Each treatment had three replicates and a total of 216 fish were used. After 72 hours starvation, endogenous TAN excretion was measured for each temperature and density. To investigate exogenous TAN excretion, fish were handfed a commercial diet containing 51.6% crude protein twice a day for 7 days, at 08:00 and 16:00. Water was sampled from both inlets and outlets of chambers every 2 hours over a 24 hour period. Both endogenous and exogenous TAN excretion increased with increases in temperature and density (P<0.05). Mean daily endogenous TAN excretion rates at 10, 15, 20, and $25^{\circ}C$ were 88.8, 101.1, 125.0, and $143.3\;mg\;TAN\;kg^{-1}\;d^{-1}$ at low density, and 105.2, 119.2, 141.5, and $168.8\;mg\;TAN\;kg^{-1}\;d^{-1}$ at high density, respectively. Mean daily exogenous TAN excretion rates at 10, 15, 20, and $25^{\circ}C$ were 343.5, 403.7, 535.7, and $601.7\;mg\;TAN\;kg^{-1}\;d^{-1}$ at low density, and 391.9, 479.7, 611.9, and $683.4\;mg\;TAN\;kg^{-1}\;d^{-1}$ at high density, respectively. The exogenous TAN excretion rate peaked 10~12 hours after the first feeding under all temperatures and densities. The TAN loss for ingested nitrogen increased with increases in temperature and density (P<0.05), ranging from 27.9 to 50.1% at low density and 31.7 to 56.9% at high density. This study provides empirical data for estimating ammonia excretion and managing the culture of red seabream under the given temperatures and densities.

• 환경생물
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• 제26권3호
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• pp.138-144
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• 2008

본 연구에서는 자바틸라피아(체장 10$\pm$1.0cm, 체중 173$\pm$4.2g)를 사용하여 염분의 변화에 따른 산소소비율, 아가미 호흡수 및 암모니아 배설률을 조사하였다. 담수(0 psu)에서 사육하던 자바틸라피아를 염분 0(대조구), 3, 9. 15, 21 및 32 psu로 이동하였을 때 시간경과에 따른 생존율을 조사하였다. 단계적 인 염분변화는 담수(0 psu, 대조구)로부터 염분을 1일 3psu씩 증가시켜 3, 9, 15, 21 및 32 psu가 되도록 조절하였다. 급격한 변화는 각 사육 염분(0, 9, 15, 21, 32 psu)에서 각각 4개의 다른 염분으로 순화 없이 바로 옮겨 조사하였다. 본 연구결과에서 나타난 갑작스런 염분변화는 96시간 반수치사농도(96 hr-TL$_{50}$)는 23.3 psu로 나타났다. 단계적으로 염분을 옮겼을 때 3 psu로부터 27 psu까지 염분증가에 따라 산소소비율과 호흡수는 높아지는 것으로 나타났으며, 32 psu에서는 0 psu보다 낮아지는 경향을 보였다. 암모니아 배설량은 15 psu에서 가장 높은 배설률을 보이고 21 psu이상에서는 불규칙한 배설률을 보였다. 이러한 결과로 볼 때, 담수에서 15 psu 이상으로 갑작스런 이동은 항상성 유지에 문제가 있는 것으로 나타났으며, 염분에 적응사육한다고 할 때 15 psu 이하에서 단계적인 순화를 거쳐서 사육하는 것이 안전하다고 판단되어진다.

• 한국가금학회지
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• 제34권4호
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• pp.287-294
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• 2007

본 연구는 질소원 결핍 배지에서 배양되어 in vitro 실험상에서 항균 활력이 있는 것으로 증명된 Aspergillus oryzae 배양물을 질소원 공급 배지와 비교하여 육계의 증체, 사료 섭취량, 영양소 이용율, 유해 가스 생산 및 분내 미생물 균총 변화 등에 미치는 영향을 조사하기 위하여 시행되었다. 총 168수 2일령 육계를 7 처리구(대조구, 질소원 공급 배지에서 자란 Aspergillus oryzae 배양물(NAOF) 0.05, 0.1, 0.5%, 질소원 결핍 배지에서 자란 Aspergillus oryzae 배양물(NNAOF) 0.05, 0.1, 0.5%에 배치하였다. 본 실험 결과 Aspergillus oryzae 첨가로 사료의 기호성이 증가되었으며, Aspergillus oryzae 배양시 질소원 결핍 처리는 일반적인 배양 방법에 비하여 증체와 사료 기호성에 더욱 효과적으로 작용하였다. 영양소 소화율은 질소원 처리 구간의 유의적 차이는 없었지만, 대조구에 비하여 Aspergillus oryzae 배양물을 첨가시에 영양소의 소화율이 전반적으로 향상되었는데, 이러한 결과는 육계의 소장 및 대장의 pH 조절에 관여하고 유익균의 생장을 촉진하며, 유해균의 증식을 억제할 수 있는 효소나 대사산물이 분비되어 긍정적으로 작용하여 사료의 기호성 및 영양소의 소화율을 증진시킨 결과라고 추정할 수 있다. 처리에 따른 분내 총균수 변화는 유의적(p<0.05)인 차이를 보였으며, 균수는 NNAOF>NAOF>대조구순으로 나타났다. E. coli와 살모넬라에서는 Aspergillus oryzae 배양물 처리구가 대조구에 비해 현저하게(p<0.05) 감소되었고, 특히 NNAOP 처리구에서 가장 낮게 나타났다. 분내 암모니아 가스 발생량을 조사한 결과, 실험실적으로 검사할 수 있는 발생량은 대조구>NAOF>NNAOF 순으로 나타났다. 본 연구 결과는 NNAOF을 이용한 육계 생산은 생산성 향상과 더불어 환경 오염을 예방할 수 있는 방법임을 시사하므로 더욱 심도있는 연구가 필요한 것으로 판단된다.

• Applied Biological Chemistry
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• 제19권3호
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• pp.155-161
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• 1976

종국(種麴)의 종류(種類)를 달리하여 제국(製麴)한것으로 담금하여 발효과정중(醱酵過程中)의 효소활성(酵素活性), 미생물균수(微生物菌數), 일반성분(一般成分), 질소용해율등(窒素溶解率等)의 변화(變化)에 대(對)하여 실험(實驗)한 결과(結果)는 다음과 같다. (1) 간장 발효중(醱酵中)의 중성(中性) 및 alkali성(性) protease의 활성(活性)은 발효기간(醱酵期間)의 경과(經過)에 따라 실활(失活)되였고 세균함유종국구(細菌含有種麴區)가 더욱 현저하였다. (2) 간장 발효중(醱酵中)의 미생물균수(微生物菌數)는 발효기간(醱酵期間)의 경과(經過)에 따라 각시험구(各試驗區) 모두 증가하는 경향을 나타났으며 특히 세균함유종국구(細菌含有種麴區)가 현저하였다. (3) 일반성분중(一般成分中) TN, amino-N. ammonia-N 등은 발효기간(醱酵期間)의 경과(經過)에 따라 증가하였으며 alcohol, 유리환원당, 순고형물(純固形物) 등은 발효초기(醱酵初期)에 다소 증가하다가 점차 감소하는 경향을 보였다. (4) 세균함유종국구(細菌含有種麴區)는 타시험구(他試驗區)에 비(比)하여 ammonia-N의 함량(含量)이 높았으나 pH는 낮은 편이였다. (5) 질소용해율(窒素溶解率) 및 관능검사의 결과(結果) 순수종국구(純粹種麴區)가 가장 좋았으며 세균함유종국구(細菌含有種麴區)가 가장 불량(不良)하였다.

• 대한환경공학회지
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• 제27권11호
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• pp.1222-1227
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• 2005

대표적인 질소제거 시스템인 무산소-산소공정을 대상으로 주어진 유입수 수질 조건에서 최대의 질소제거를 위한 최적의 슬러지 반송비를 질화/탈질 반응식을 이용하여 양론적으로 계산하였다. 양론적 계산에 고려된 수질 항목은 질화/탈질에 영향을 미치는 암모니아성 질소, 질산성질소, 알칼리도, COD, 용존산소로 설정하였다. 최대의 질소제거를 위한 최적의 슬러지 반송비를 앞의 5가지 유입수 항목으로 나타내었다. 양론적 계산에 의한 각 공정의 유출수와 최종 유출수 중의 TN농도가 실제 보고된 하 폐수 처리장의 TN농도와 잘 일치 하였다. 또한 양론적 계산에 의해 실제 처리장 최종 유출수 중의 TN농도를 ${\pm}5.0\;mg/L$ 내에서 예측 가능하였다.

• 한국환경과학회지
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• 제23권1호
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• pp.153-156
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• 2014

This study was conducted to evaluate the effects of sea urchin shell powder on nitrogen characteristics in poultry litter by assigning ninety 1-d-old male broiler chicks (Arbor Acres) to one of 3 treatments (control, 1% sea urchin shell powder, and 1% feed additives) in 3 replicates of 10 birds each. For all treatments, the overall dry matter contents were decreased (P < 0.05) as time increased, except for at 1 week. When compared with controls, the dietary sea urchin shell powder and feed additives for 0 and 3 weeks did influence their TN contents, but not for 1, 2 and 4 weeks. The treatments with sea urchin shell powder and feed additives had a significant (P < 0.05) influence on $NH_3$-N in poultry litter compared with controls. However, at 4 weeks, no marked differences were observed in $NH_3$-N contents among treatments. Treatments with 1% sea urchin shell powder might enhance the value of poultry litter as N fertilizer.

• Asian-Australasian Journal of Animal Sciences
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• 제20권6호
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• pp.900-907
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• 2007

Three male Gayal (Bos frontalis) and three male Yunnan Yellow cattle (Bos taurus) were fed pelleted lucerne and measurements made of digestibility, nitrogen utilisation, rumen fermentation and microbial population and key plasma metabolites. Total actual dry matter intake was similar but when expressed in terms of live weight or metabolic live weight feed intakes were significantly higher (p<0.05) for Gayal than cattle. Apparent digestibilities of dry matter, organic matter, fibre and dietary nitrogen were similar for both Gayal and cattle. Rumen ammonia nitrogen and total volatile fatty acids were significantly higher (p<0.05) for Gayal than cattle and total numbers of viable rumen bacteria, cellulolytic and amylolytic bacteria, but not proteolytic bacteria nor protozoa, were significantly greater (p<0.05) for Gayal than cattle. Although Gayal have a different rumen ecology to cattle, similar digestive parameters were exhibited. Further research is required to establish relationship between rumen ecology and digestive parameters.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.1615-1615
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• 2001

During the past ten years, Near Infrared Spectroscopy has been successfully applied to the analysis of a great variety of agriculture products. Previous works (Morra et al., 1991; Salgo et al., 1998) have shown the potential of this technology for soil analysis, estimating different parameters just with one single scan. The main advantages of NIR applications in soils are the speed of response, allowing the increase of the number of samples analysed to define a particular soil, and the instantaneous elaboration of recommendations for fertilization and soil amendment. Another advantage is to avoid the use of chemical reagents at all, being an environmentally safe technique. In this paper, we have studied a set of 129 soil samples selected from representative glasshouse soils from Southern Spain. The samples were dried, milled, and sieved to pass a 2 mm sieve and then analysed for organic carbon, total nitrogen, inorganic nitrogen (nitrate ammonium), hygroscopic humidity, pH and electrical conductivity in the 1:1 extract. NIR spectra of all samples were obtained in reflectance mode using a Foss NIR Systems 6500 spectrophotometer equipped with a spinning module. Calibration equations were developed for seven analytical parameters (ph, Total nitrogen, organic nitrogen, organic carbon, C/N ratio and Electric Conductivity). Preliminary results show good correlation coefficients and standard errors of cross validation in equations obtained for Organic Carbon, Organic Nitrogen, Total Nitrogen and C/N ratio. Calibrations for nitrates and nitrites, ammonia and electric conductivity were not acceptable. Calibration obtained for pH had an acceptable SECV, but the determination coefficient was found very poor probably due to the reduced range in reference values. Since the estimation of Organic Carbon and C/N ratio are acceptable NIIRS could be used as a fast method to assess the necessity of organic amendments in soils from Mediterranean regions where the low level of organic matter in soils constitutes an important agronomic problem. Furthermore, the possibility of a single and fast estimation of Total Nitrogen (tedious determination by modifications of the Kjeldahl procedure) could provide and interesting data to use in the estimation of nitrogen fertilizer rates by means of nitrogen balances.

• Journal of Microbiology and Biotechnology
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• 제13권2호
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• pp.309-312
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• 2003

A bacterial strain NB01, isolated from wastewater, was found to utilize nitrobenzene (NB) as the sole source of nitrogen, carbon, and energy. The strain was classified as a member of a high G+C Gram-positive group and identified as Mycobacterium chelonae based on an analysis of its 16S rRNA gene sequence. The strain grew on NB with a concomitant release of about 63% of the total available nitrogen as ammonia, suggesting a reductive degradation mechanism. The optimal pH and temperature for degradation were PH 7.0-8.0 and $30^{\circ}C$, respectively. The cell growth was retarded at NB concentrations above 1.8 mM. The degradation of NB followed Michaelis-Menten kinetics within the tolerance range, and the $K_m$ and maximum specific removal rate for NB were 0.33 mM and $11.04\;h^{-1}$, respectively.

• 한국물환경학회지
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• 제25권1호
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• pp.142-150
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• 2009

The distribution of organic nitrogen and its decomposition rate were studied in the Youngsan River and the Sumjin River system in Korea. Samples were conducted seasonally in June, August, December of 2006, and February of 2007. Collected samples were incubated for 20 days in a dark chamber ($20{\pm}1^{\circ}C$) and analyzed the changes of nitrogen form (particulate organic nitrogen, dissolved organic nitrogen, ammonia, nitrite, and nitrate). The mean total nitrogen (TN) concentration in the Youngsan River and the Sumjin River were $2.62mgN{\cdot}L^{-1}$ and $1.53mgN{\cdot}L^{-1}$, respectively. TN comprised of 65% DIN and 35% ON. The decomposition coefficients of organic nitrogen were also determined by two different fitting models. The decomposition rates of nitrogen species (TON, LPON, LDON, ${NH_4}^+$ and ${NO_2}^-$) ranged from 0.024 to $1.043day^{-1}$ in the Youngsan River and 0.008 to $0.693day^{-1}$ in the Sumjin River, respectively. The result of this study can give a guide to the selection of parameters in the calibration processes of water quality models.