• 생물환경조절학회지
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• 제5권2호
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• pp.145-151
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• 1996

수경재배시 변화하는 배양액 pH를 동적으로 조절하기 위한 방법으로 생리적 산, 알칼리와 화학적 산, 알칼리의 효율성을 검토하였다. 배양액 자동조절시스템에 생리적 산, 알칼리로 NH$_4$H$_2$PO$_4$ 및 NaNO$_3$를 이용하고, 화학적 산으로 H$_2$SO$_4$를 이용하여 상추를 재배한 결과, 처리에 관계없이 배양액의 pH를 안정적으로 조절할 수 있었다. 생리적 산, 알칼리의 경우 화학적 산, 알칼리보다 배양액 pH를 급격히 변화시켰으며, 그에 따른 해작용은 나타나지 않았다. 그러므로 상추의 순수수경재배시 배양액의 pH를 자동제어 하기 위한 방법으로, 생육 기간 중에는 화학적 산, 알칼리를 이용하여 pH를 조절하고 수확 며칠 전부터 NH$_4$H$_2$PO$_4$를 화학적 알칼리와 겸해서 공급하는 것이 바람직한 것으로 사료된다.

• 한국생물환경조절학회:학술대회논문집
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• 한국생물환경조절학회 1995년도 특강 및 학술논문발표요지
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• pp.75-78
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• 1995

양액재배시 배양액의 pH는 중요한 재배인자이며, 이는 용수의 성질에 따라 큰 영향을 받는다. 용수로는 지하수를 많이 사용하나, 수돗물을 사용하는 경우도 흔히 있다. 수돗물은 pH가 7.5 정도로, pH가 낮은 용수를 사용할 경우와 같은 조성의 배양액을 조제하면 배양액의 pH가 높아 생육에 나쁜 영향을 끼친다. 따라서, 용수의 성질에 따라 배양액의 조성을 달리하여 pH를 적정수준으로 유지하는 것이 중요하다. (중략)

• 한국물환경학회지
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• 제31권4호
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• pp.387-391
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• 2015

This study was performed to evaluate the effect of pH (8-12) and molar ratio of magnesium and phosphate ($[Mg^{2+}]/[PO_4{^{3-}}]$) (0.6-1.4) on struvite crystallization of anaerobic digester supernatant using seawater as magnesium source. pH range of 9-10 is favorable for ammonium and phosphate recoveries. The recovery efficiency of ammonium was highest at $[Mg^{2+}]/[PO_4{^{3-}}]$ of 1.0 and pH 10. On the other hand, high phosphate recovery efficiency (> 99%) was achieved at ($[Mg^{2+}]/[PO_4{^{3-}}]$) of 1.4 and pH 10. The results demonstrated that seawater can be considered as low-cost magnesium source to recover phosphorus from anaerobic digester supernatant.

• 한국식품위생안전성학회지
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• 제11권4호
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• pp.291-297
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• 1996

The role of cytochrome P-450 2E1 (P450 2E1) in the early phase of alcoholic fatty liver was examined. Female rats were pretreated with either allyl sulfide (200 mg/kg, po), disulfiram (500 mg/kg, po), YH 439 (250 mg/kg, po) or pyrazine (200 mg/kg/day$\times$2 days, ip). Marked changes in carbon tetrachloride-induced hepatotoxicity and caboxyhemoglobin (COHb) elevation due to dichloromethane administration were observed in rats treated with one of the P450 2E1 modulators. A single dose of ethanol (6 g/kg, po) increased the hepatic triglyceride contents approximately 2 fold, which was inhibited completely by YH 439 pretreatment. However, the other P450 2E1 modulators failed to alter the ethanol-induced hepatic triglyceride accumulation. In vitro hepatic microsomal enzyme activity was determined in 4 week old premature and 12 week old adult rats. Aminopyrine-N demethylation was not different, but p-nitrophenol hydroxylation and p-nitroanisole O-demethylation were significantly higher in premature rats. However, no difference in the triglyceride accumulation induced by an intraperitoneal dose of ethanol (3 g/kg) was noted between premature and adult rats. The results suggest that the P450 2E1 activity dose not play an important role in the induction of acute alcoholic fatty liver.

• 한국환경농학회지
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• 제28권2호
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• pp.165-170
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• 2009

환원상태가 발달된 담수상태의 토양이나 습지생태계에서 $NO_3^-$는 환원상태의 진전을 지연시키는 완충역할을 할 수 있다. 논토양에서 $NO_3^-$가 Fe의 환원과 그에 따른 P의 가용화에 미치는 영향을 조사하였다. 담수 후 10 cm 깊이 토양의 산화환원전위 변화는 $NO_3^-$를 처리한 토양과 처리하지 않은 토양에서 현저하게 달리 나타났으며, $NO_3^-$의 환원이 일어나는 동안에는 산화환원전위가 330${\sim}$360 mV 범위에서 유지되었다. 그리고 이 기간 동안 Fe의 환원은 현저히 억제되었다. $NO_3^-$를 처리한 토양 용액의 $PO_4^{3-}$ 함량은 담수 이후 0.2${\sim}$0.3 mg/L 수준 또는 그 이하로 유지되었으며, 반면 $NO_3^-$를 처리하지 않은 경우에는 담수 후 9일째부터 Fe의 환원과 함께 토양 용액의 $PO_4^{3-}$ 함량이 급격히 증가하였다. 일반적인 토양에서 무기태 P의 상당부분이 Fe 산화물에 고정된 형태 및 Fe와 결합된 형태로 존재하므로 Fe의 환원에 따라서 $PO_4^{3-}$가 함께 용출되는 것이다. 이상의 결과를 보면 토양중의 $NO_3^-$가 $Fe^{2+}$와 $PO_4^{3-}$의 용출을 조절하는 요인인 것으로 확인할 수 있다. 토양 용액중의 $NO_3^-$ 농도가 1 mg/L 이상으로 유지되는 상태에서는 토양의 산화환원전위가 330 mV 이하로 낮아지지 못하며, 따라서 Fe의 환원과 그에 따른 P의 용출 또한 현저히 억제되는 것으로 판단된다.

• 한국환경보건학회지
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• 제34권5호
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• pp.374-381
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• 2008

In this study, the factors affecting biological N and P removal using SND (simultaneous nitrification and denitrification) process were investigated and evaluated to examine the possibility of treating N and P through SND with NADH by surveying N and P traces in an aeration tank. Variations of $NH_4^+$-N+$NO_3^-$-N concentration were used to estimate the degree of SND in each point (P2, P3, P4, P5) of the aeration tank and these variations showed that denitrification efficiency in P2 (front zone), nitrification and denitrification efficiencies in P4 (middle zone) were 67%, 86% and 39%, respectively. When $PO_4^{-3}$-P concentration was analyzed in each point of the aeration tank, it was shown that $PO_4^{-3}$-P concentration coming into P2 was 1.25 mg/L, which increased to 2.22 mg/L by P release in P2 zone and then decreased to 0.74 mg/L by P uptake in P4. Consequently, we were able to estimate which high P removal efficiency observed in this study was caused by biological phosphorus removal. To determine the operating factors affecting effluent T-N, we analyzed the correlation among FN/M ratio, C/N ratio, Temp., SRT etc and these results showed that the correlation among FN/M ratio, C/N ratio and Temp was not high. However, the relationship of SRT and other parameters (effluent $NH_4^+$-N and effluent BOD) and the short SRT could have an affect on effluent $NH_4^+$-N and so effluent BOD could be increased. Thus, SRT operation should be controlled over 10 days. The results for analyzing the correlation between SRT and influent $NO_3^-$-N in order to investigate the operating factors affecting effluent T-P showed that T-P or $PO_4^{-3}$-P was not highly correlation with SRT, whereas $PO_4^{-3}$-P concentration increased along with increasing $NO_3^-$-N concentration into P2. Based on these results, we concluded, using regression analysis (R2=0.97), that effluent $PO_4^{-3}$-P concentration depends on $NO_3^-$-N concentration into P2.

• Mycobiology
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• 제44권4호
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• pp.283-290
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• 2016

A double-stranded RNA (dsRNA) mycovirus was detected in malformed fruiting bodies of Pleurotus ostreatus strain ASI2792, one of bottle cultivated commercial strains of the edible oyster mushroom. The partial RNA-dependent RNA polymerase (RdRp) gene of the P. ostreatus ASI2792 mycovirus (PoV-ASI2792) was cloned, and a cDNA sequences alignment revealed that the sequence was identical to the RdRp gene of a known PoSV found in the P. ostreatus strain. To investigate the symptoms of PoV-ASI2792 infection by comparing the isogenic virus-free P. ostreatus strains with a virus-infected strain, isogenic virus-cured P. ostreatus strains were obtained by the mycelial fragmentation method for virus curing. The absence of virus was verified with gel electrophoresis after dsRNA-specific virus purification and Northern blot analysis using a partial RdRp cDNA of PoV-ASI2792. The growth rate and mycelial dry weight of virus-infected P. ostreatus strain with PoV-ASI2792 mycovirus were compared to those of three virus-free isogenic strains on 10 different media. The virus-cured strains showed distinctly higher mycelial growth rates and dry weights on all kinds of experimental culture media, with at least a 2.2-fold higher mycelial growth rate on mushroom complete media (MCM) and Hamada media, and a 2.7-fold higher mycelial dry weight on MCM and yeast-malt-glucose agar media than those of the virus-infected strain. These results suggest that the infection of PoV mycovirus has a deleterious effect on the vegetative growth of P. ostreatus.

• 한국동물위생학회지
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• 제35권2호
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• pp.83-90
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• 2012

Porcine rotaviruses are the most common causes of viral gastroenteritis in piglets around the world. The major G genotypes of porcine rotaviruses causing diarrhea were G4, G5 and G11 genotypes. Recently, G9 genotype rotaviruses were problemed at swine farms and frequently recognized from diarrheic piglets. In this study, a porcine rotavirus (PoRV-1) was isolated from piglet showing diarrhea using MA104 cells and confirmed as rotavirus by electron microscopy, genomic RNA electropherotyping and indirect immunofluorescence antibody tests. The nucleotide sequence of the VP7 gene of PoRV-1 was determined and compared with those of other genotype rotavirus strains from other parts of the world. Also, the nucleotide sequences of VP4, VP6 and NSP4 genes of PoRV-1 were determined and compared with those of other rotavirus strains from other countries. The results showed that the PoRV-1 isolate belonged to the G9 genotype and the P, I and E genotypes of PoRV-1 were P[23], I5 and E1, respectively. The Korean G9 PoRV-1 isolate and its nucleotide sequence data would be usefully used for the development of porcine rotavirus vaccines in near future.

• 한국해양환경ㆍ에너지학회지
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• 제17권4호
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• pp.306-317
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• 2014

이 연구는 새만금 방조제가 조성된 이후 새만금호에서 영양염($NO_3$-N, $NO_2$-N, $NH_4$-N, TN, $PO_4$-P, TP, DISi)의 거동을 이해하기 위해 수행되었으며, 특히 2008년~2010년까지 새만금호의 표층과 저층에서 매월 관측된 환경인자(수온, 염분, 용존산소, 부유물질, Chl-a)와 상호 비교하여 특징을 논의하였다. 표층에서 $NO_3$-N, TP, $PO_4$-P, DISi는 제거현상을 보였고, $NO_2$-N, $NH_4$-N, Chl-a는 첨가현상을 보였다. 저층에서는 $NO_3$-N을 제외하고 모든 항목들이 첨가현상을 보였다. 따라서 $NO_3$-N을 제외한 나머지 영양염들은 저층수에서 지속적으로 공급되고 있음을 의미한다. 혼합모델을 이용하여 저층수에서 영양염의 거동을 분석한 결과, 생지화학적 과정에 의해 $NO_3$-N이 주로 하계에 감소되는 것으로 나타났고, $NH_4$-N과 $PO_4$-P는 하계에 증가되는 것으로 나타났다. 특히 $PO_4$-P와 $NH_4$-N의 증가는 강하구 쪽에서 더욱 뚜렷하게 나타났고, 표층과 저층 사이의 DO의 농도 차이와 강한 양의 상관성을 보였다. DISi도 저층수에서 지속적으로 공급되고 있음을 보였으나, $NH_4$-N과 $PO_4$-P와는 다르게 하계뿐만 아니라 춘계에도 공급되는 경향을 보였다. 또한 $NH_4$-N과 $PO_4$-P가 방조제 쪽보다 하구 쪽에서 더 많이 공급되는 것과는 다르게 DISi는 양쪽에서 유사하게 공급됨을 보였다. 이러한 DISi의 특징은 퇴적물로부터 분자확산에 의한 flux를 계산한 결과, 저층수에서 공급되는 영양염은 퇴적물로부터 용출되는 것 이외에 SGD 등 다른 유입기원이 있는 것을 암시한다.

• Asian-Australasian Journal of Animal Sciences
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• 제17권8호
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• pp.1131-1138
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• 2004

The objective of this study was to investigate the effects of different sources of Ca and P on urine and ileal digesta pH, and ammonia ($NH_{3}$), methane ($CH_{4}$), and odor emission. In experiment 1, eight pigs (commercial three-way cross; initial BW 67$\pm$3 kg) were arranged in a repeated 4$\times$4 Latin Square design. All pigs were equipped with a T-cannula in the distal ileum. Four corn-soybean meal based diets were formulated. Diet 1 was the control in which dicalcium phosphate (DCP) and limestone ($CaCO_{3}$) were used as the sources of inorganic P and Ca. In Diets 2 and 3, ${H_{3}}{PO_{4}}$, monocalcium phosphate (MCP), and $CaSO_{4}$replaced DCP and $CaCO_{3}$ as the inorganic sources of P and Ca. Diet 4 was similar to Diet 1 except that it was fortified with HCl to provide an acid load similar to that of diet 2. Urine and ileal digesta pH were determined in pigs fed each of these diets. In Exp. 1, urine pH decreased (p<0.05) in animals consuming diets containing ${H_{3}}{PO_{4}}$-$CaSO_{4}$ (5.85$\pm$0.38) and MCP-$CaSO_{4}$(5.73$\pm$0.30) compared with the DCP-$CaCO_{3}$ diet (6.89$\pm$0.24). In the pigs consuming ${H_{3}}{PO_{4}}$-$CaSO_{4}$, ileal digesta pH decreased compared with the control (5.52$\pm$0.28 vs. 6.66$\pm$0.17; p<0.05). Based on the results of Exp. 1, a total of four trials were performed in environmental chambers for determining how $NH_{3}$, $NH_{4}$, and odor were affected by the different dietary Ca and P sources (Exp. 2). In Exp. 2, pigs fed the ${H_{3}}{PO_{4}}$-$CaSO_{4}$ diet had decreased (30%) $NH_{3}$ emissions compared with the control (p<0.05). Also, a combination of MCP-$CaCO_{3}$-$CaCl_{12}$ decreased $NH_{3}$ emission by 15% (p<0.05). Emission of $CH_{4}$ was decreased only with the ${H_{3}}{PO_{4}}$-$CaSO_{4}$ diet with 14% (p<0.05). Odorant emission of phenolics and volatile fatty acids increased roughly three-fold with the DCP-$CaSO_{4}$ diet but was not affected by other test diets. In conclusion, acidogenic Ca and P sources in swine diets can decrease the urinary pH and reduce $NH_{3}$ and $CH_{4}$ emission from swine facilities.