• KSBB Journal
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• 제14권4호
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• pp.422-428
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• 1999

Alcaligenes latus 유래의 phbC 유전자를 A. eutrophus에 재도입시킨 형질전환균주를 이용하여 높은 4HB 몰분율을 갖는 P(3HB-4HB)의 고농도 생산을 시도하였다. 형질전환균주는 총균체량, P(3HB-4HB) 농도, 그리고 축적률에서 모균주에 비해 다소 증가한 반면 P(3HB-4HB)내의 4HB 몰분율은 23.5 mol%로 모균주의 12.3 mol%에 비해 현저히 증가하였다. 이는 phbC유전자의 증폭으로 인해 해당과정에서 생성된 3HB와 전구물질인 ${\gamma}$-butyrolacton에서 전환된 4HB의 중합반응이 촉진되기 때문으로 사료된다. 또한 ${\gamma}$-butyrolacton의 농도 $Mg^{2-}$ 이온, 그리고 citrate 첨가량이 P(3HB-4HB)의 농도, 축적률, 그리고 4HB 몰분율에 미치는 영향을 검토하였다. P(3HB-4HB)내의 4HB 몰분율을 증대시키기 위하여 일반적으로 사용되는 2단계 배양법을 변형시켜 ${\gamma}$-butyrolacton과 citrate의 첨가시기를 늦춘 2단계 배양법을 활용하여 P(3HB-4HB)내의 4HB 몰분율을 61.0 mol%로 증가시킬 수 있었다. 또한 ${\gamma}$-butyrolacton의 첨가량을 조절하여 P(3HB-4HB)내의 4HB 몰분율이 92.0 mol%에 이르는 homopolymeric P(4HB)를 생산할 수 있었으며, 그 구조를 $^1$H-NMR을 통해 확인하였다.

• KSBB Journal
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• 제25권3호
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• pp.239-243
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• 2010

식물성 오일 또는 glycerol로부터 Ralstonia eutropha 여섯 균주의 polyhydroxyalkanoates (PHA) 합성 특성을 조사하였다. 탄소원으로 soybean oil, olive oil, 또는 glycerol 만을 공급시 poly(3-hydroxybutyrate) homopolymer가 생성되었으며, $\gamma$-butyrolactone 또는 pentanoic acid를 함께 공급시 poly(3-hydroxybutyrate-co-4-hydroxybutyrate) 또는 poly(3-hydroxybutyrate-co-3-hydroxyvalerate) copolymer가 각각 합성되었다. 최종 균체농도 및 PHA 함량면에서 최적인 균주는 R. eutropha KCTC 2662로 결정되었으며, 최적 기질인 soybean oil 20 g/L로부터 72 h에 균체농도 1.7~9.2 g/L, PHA 함량 70~92 wt%를 얻을 수 있었다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권6호
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• pp.603-606
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• 2005

Ralstonia eutropha NCIMB 11599 and ATCC 17699 were grown, and their productions of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) [P(3HB-co-4HB)] compared. In flask cultures of R. eutropha NCIMB 11599, cell concentration, P(3HB-co-4HB) concentration and polymer content decreased considerably with increases in the ${\gamma}-butyrolactone$ concentration, and the 4HB fraction was also very low (maximum 1.74 mol%). In fed-batch cultures of R. eutropha NCIMB 11599, glucose and ${\gamma}-butyrolactone$ were fed as the carbon sources, under a phosphate limitation strategy. When glucose was fed as the sole carbon source, with its concentration controlled using an on-line glucose analyzer, 86% of the P(3HB) homopolymer was obtained from 201g/L of cells. In a two-stage fed-batch culture, where the cell concentration was increased to 104g/L, with glucose fed in the first step and constant feeding of ${\gamma}-butyrolactone$, at 6g/h, in the second, final cell concentration at 67h was 106g/L, with a polymer content of 82%, while the 4HB fraction was only 0.7mol%. When the same feeding strategy was applied to the fedbatch culture of R. eutropha ATCC 17699, where the cell concentration was increased to 42 g/L, by feeding fructose in the first step and ${\gamma}-butyrolactone$ (1.5g/h) in the second, the final cell concentration, polymer content and 4HB fraction at 74h were 51g/L, 35% and 32 mol%, respectively. In summary, R. eutropha ATCC 17699 was better than R. eutropha NCIMB 11599 in terms of P(3HB-co-4HB) production with various 4HB fractions.

• 대한약학회:학술대회논문집
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• 대한약학회 2001년도 Proceedings of International Convention of the Pharmaceutical Society of Korea
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• pp.282.1-282.1
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• 2001

• BMB Reports
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• 제32권3호
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• pp.254-258
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• 1999

The NADPH-dependent succinic semialdehyde reductase is one of the key enzymes in the brain GABA shunt, and it catalyzes the formation of the neuromodulator $\gamma$-hydroxybutyrate from succinic semi aldehyde. This enzyme was inactivated by diethylpyrocarbonate (DEP) with the second-order rate constant of $1.1{\times}10^3\;M^{-1}min^{-1}$ at pH 7.0, $25^{\circ}C$, showing a concomitant increase in absorbance at 242 nm due to the formation of N-carbethoxyhistidyl derivatives. Complete inactivation of succinic semialdehyde reductase required the modification of five histidyl residues per molecule of enzyme. However, only one residue was calculated to be essential for enzyme activity by a statistical analysis of the residual enzyme activity. The inactivation of the enzyme by DEP was prevented by preincubation of the enzyme with the coenzyme NADPH but not with the substrate succinic semialdehyde. These results suggest that an essential histidyl residue involved in the catalytic activity is located at or near the coenzyme binding site of the brain succinic semialdehyde reductase.

• Animal Bioscience
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• 제34권4호
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• pp.575-583
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• 2021

Objective: The aim of the study was to determine the effect of parity and the stage of lactation on the metabolic profile of cows based on the basic chemical milk components and the blood parameters. Methods: The study material consisted of high-yielding Holstein-Friesian cows. In total, 473 cows were examined. According to the parity, cows were divided into four groups: primiparous (P), and multiparous in the second (M2), in the third (M3), and in subsequent lactations (M4). The feeding of cows was based on total mixed ration (TMR) ad libitum. Milk and blood samples were collected individually from each cow three times per standard lactation period. Results: Greater exacerbation of changes in the dynamics of the blood plasma parameters examined was proved for multiparous cows. The highest value of β-hydroxybutyrate acid (0.946 mmol/L) was found for multiparous cows from group M3 at the beginning of lactation. However, it was still in the normal range. The results showed aspartate aminotransferase, and gamma-glutamyl transferase (GGT) activities in dairy cows during lactation had significant variations taking in to account stage of lactation. The highest activity of GGT was found in the group of the oldest cows and measured from 26.36 U/L at the beginning of lactation to 48.75 U/L at the end of the lactation period. Conclusion: The time-related changes in the concentrations of the biochemical parameters described differ markedly among lactating cows, though the housing conditions on the research dairy farm are highly standardised. This indicates that the ability to cope with metabolic stress is mainly affected by the individual predispositions of cows and feed nutrient supply in different stage of lactation. Especially, the feed nutrient supply (in net energy for lactation), which was the best in TMR 1 in comparison TMR 3.

• BMB Reports
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• 제28권2호
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• pp.112-117
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• 1995

Succinic semialdehyde reductase was inactivated by o-phthalaldehyde. The inactivation followed pseudo-first order kinetics, and the second-order rate constant for the inactivation process was 28 $M^{-1}s^{-1}$ at pH 7.4 and $25^{\circ}C$. The absorption spectrum ($\lambda_{max}$ 337 nm) and fluorescence excitation ($\lambda_{max}$ 340 nm) and fluorescence emission spectra ($\lambda_{max}$ 409 nm) were consistent with the formation of an isoindole derivative in the catalytic site between a cysteine and a lysine residue approximately about 3 $\AA$ apart. The substrate, succinic semialdehyde, did not protect enzymatic activity against inactivation, whereas the coenzyme NADPH protected against o-phthaladehyde induced inactivation of the enzyme. About 1 isoindole group per mol of the enzyme was formed following complete loss of enzymatic activity. These results suggest that the amino acid residues of the enzyme participating in a reaction with o-phthalaldehyde are cysteinyl and lysyl residues at or near the NADPH binding site.

• Asian-Australasian Journal of Animal Sciences
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• 제32권5호
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• pp.648-656
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• 2019

Objective: An experiment was conducted to determine the effect of reduced energy density of close-up diets on metabolites, lipolysis and gluconeogenesis in cows during the transition period. Methods: Thirty-nine Holstein dry cows were blocked and assigned randomly to three groups, fed a high energy density diet (HD, 1.62 Mcal of net energy for lactation $[NE_L]/kg$ dry matter [DM]), a medium energy density diet (MD, $1.47Mcal\;NE_L/kg\;DM$), or a low energy density diet (LD, $1.30Mcal\;NE_L/kg\;DM$) prepartum; they were fed the same lactation diet to 28 days in milk (DIM). All the cows were housed in a free-stall barn and fed ad libitum. Results: The reduced energy density diets decreased the blood insulin concentration and increased nonesterified fatty acids (NEFA) concentration in the prepartum period (p<0.05). They also increased the concentrations of glucose, insulin and glucagon, and decreased the concentrations of NEFA and ${\beta}-hydroxybutyrate$ during the first 2 weeks of lactation (p<0.05). The plasma urea nitrogen concentration of both prepartum and postpartum was not affected by dietary energy density (p>0.05). The dietary energy density had no effect on mRNA abundance of insulin receptors, leptin and peroxisome proliferator-activated $receptor-{\gamma}$ in adipose tissue, and phosphoenolpyruvate carboxykinase, carnitine palmitoyltransferase-1 and peroxisome proliferator-activated $receptor-{\alpha}$ in liver during the transition period (p>0.05). The HD cows had higher mRNA abundance of hormone-sensitive lipase at 3 DIM compared with the MD cows and LD cows (p = 0.001). The mRNA abundance of hepatic pyruvate carboxy-kinase at 3 DIM tended to be increased by the reduced energy density of the close-up diets (p = 0.08). Conclusion: The reduced energy density diet prepartum was effective in controlling adipose tissue mobilization and improving the capacity of hepatic gluconeogenesis postpartum.

• 한국임상수의학회지
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• 제32권5호
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• pp.426-432
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• 2015

본 연구는 임상형 혹은 준임상형 자궁내막염에 이환된 젖소와 자궁내막염이 발생되지 않은 젖소 사이에 분만 전 후 기간 동안 혈액 대사물질의 농도를 비교하였다. 분만 전 4주, 분만 후, 분만 1, 2, 4, 6주 후 혈액을 채취하였으며, 혈청 분리 후 calcium, magnesium, non-esterified fatty acids (NEFAs), total cholesterol, albumin, urea nitrogen, ${\beta}$-hydroxybutyrate (BHBA), aspartate aminotransferase (AST), ${\gamma}$-glutamyltransferase, glucose 및 phosphorus 농도를 측정하였다. 분만 후 4주에, 임상형 혹은 준임상형 자궁내막염 발생 유무에 따라 대조군(n = 104), 임상형 자궁내막염군(n = 66) 및 준임상형 자궁내막염군(n = 37)으로 구분하였다. Calcium과 magnesium 농도는 실험 전 기간에 걸쳐 임상형 자궁내막염군이 대조군과 준임상형 자궁내막염군에 비해 낮았으나(p < 0.05 to 0.0001), NEFAs 농도는 실험전 기간에 걸쳐 임상형 자궁내막염군이 대조군에 비해 높았다(p < 0.01). Total cholesterol 농도는 분만 전 및 분만 후 기간 중 임상형 자궁내막염군이 대조군과 준임상형 자궁내막염군에 비해 낮았다(p < 0.05 to 0.001). Albumin 농도는 분만 후 기간 동안 임상형 자궁내막염군이 대조군과 준임상형 자궁내막염군에 비해 낮았다(p < 0.05 to 0.001). Urea nitrogen 농도는 분만 후 4주 및 6주에 임상형 자궁내막염군이 대조군과 준임상형 자궁내막염군에 비해 낮았다(p < 0.01). 분만 후 1주에, BHBA 농도는 임상형 자궁내막염군이 대조군에 비해 높았으나(p < 0.01), AST 농도는 임상형 자궁내막염군과 준임상형 자궁내막염군이 대조군에 비해 높았다(p < 0.05). 결론적으로, 분만 후 혈청 calcium, magnesium, total cholesterol, albumin 및 urea nitrogen 농도의 감소와 NEFAs, BHBA 및 AST 농도의 증가가 임상형 자궁내막염의 발생과 관련되었으며, 이것은 전환기 중의 균형 잡힌 영양의 중요성을 제시한다.

• 한국동물위생학회지
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• 제42권2호
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• pp.121-126
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• 2019

Metabolic profile test is used to evaluate nutritional imbalance and metabolic disease in dairy cows. The reference intervals of metabolic parameters may change according to nation, region, decades, and maintenance system. Despite the need to be periodically updated for the reference intervals of metabolic parameters, it has rarely been investigated in Korea. Therefore, this aim of study was to provide the reference intervals of metabolic parameters using dairy cows surveyed in Korea during recent years. A metabolic profile test was conducted for 2,976 clinically healthy dairy cows in Korea. Blood samples were collected for the analysis of serum metabolites. This study provided reference intervals of thirteen metabolic parameters (${\beta}$-hydroxybutyrate [${\beta}-HB$], non-esterified fatty acids [NEFA], glucose, total cholesterol [T-COL], total protein, albumin, globulin, blood urea nitrogen [BUN], aspartate aminotransferase [AST], gamma-glutamyl transferase [GGT], calcium, phosphorus, and magnesium). BUN and AST values of the current study were higher than those of previous studies. In the present study, the other metabolic parameters showed low or similar value compared to previous results. Moreover, ${\beta}-HB$, NEFA, T-COL, ALB, BUN, AST, and GGT values were affected by lactation period. This study provided information on the reference intervals of metabolites in healthy dairy cows in Korea. The reference intervals from the present study would be useful in managing and diagnosing disease of dairy cows. However, careful attention should be given in interpreting disease condition for metabolites affected by lactation.