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Fecal sterol을 이용한 울산만과 주변해역 퇴적물내 하수기인 유기물 평가
최민규,최희구,김상수,문효방 한국환경과학회 2005 한국환경과학회지 Vol.14 No.1
Surface sediments (0~4 cm) were sampled at 40 stations from Ulsan Bay and its adjacent areas of Korea, to evaluate the contamination by sewage-derived organic matters using fecal sterols. Some sterols were quantified by gas chromatography coupled to mass spectrometry (GC/MS). Total concentrations of eight sterols (coprostanol, cholesterol. cholestanol, epicholestanol, epicoprostanol, (3-sitosterol, brassicasterol, and stigmasterol) in the sediments from Ulsan Bay and its vicinity varied from 929 to 23.444 ng/g dry weight. The most predominant sterols were cholesterol and coprostanol, accounting for 33~72% of total sterols. The concentration of coprostanol known as the indicator of human feces ranged from 141 to 8,257 ng/g dry weight. In particular, the coprostanol concentrations in the sediments from Jansaengpo Harbor and Taehwa River exceeded the value of 1,000 ng/g dry weight. suggesting that these areas could be considered as the hot-spot zones by municipal sewage contamination. Some molecular indices and multivariate data analysis were used to assess the origin of these sterols in the sediments. Results showed that the major routes of sewage contamination in Ulsan Bay and its vicinity were the input through Jansaengpo Harbor and Taehwa River.
제조합 대장균에서 과발현된 Citrobacter freundii KCTC2006 유래의 β-Tyrosinase를 이용한 3,4-Dihydroxyphenyl-L-alanine의 생산
이승구,노현수,홍승표,이규종,왕지원,태동년,엄기남,방상구,김영준,성문희 한국미생물생명공학회 ( 구 한국산업미생물학회 ) 1996 한국미생물·생명공학회지 Vol.24 No.1
재조합 대장균에서 대량발현 시킨 Citrobacter freundii KCTC 2006 유래이 효소 β-tyrosinase를 이용하여 pyrocatechol, sodium pyruvate, ammonium acetate로부터 3,4-dihydroxy phenyl-L-alanine을 생산하기 위한 연구를 수행하였다. 이 효소반응에 적합한 온도 및 pH 조건은 각각 18℃와 8.5로 결정되었고, 반응액 중의 ammonium acetate와 sodium pyruvate의 농도는 각각 300 mM, 50 mM 이상으로 조절하는 것이 적합하였다. Pyrocatechol의 경우는 20 mM에서 가장 높은 반응성을 나타냈으나, 기질을 반복적으로 첨가하며 장시간 동안 효소반응을 수행하는 경우에는 pyrocatechol의 고갈을 피하기 위하여, 20 mM에서 50 mM 사이로 조절하였다. 한편, 반응액 중에 ethanol을 10% 첨가한 경우에는 반응속도가약 20% 증가하였다. 이상과 같은 효소반응특성에 기초하여 조제한 기질용액에 β-tyrosinase를 1 unit/㎖ 농도로 가하고, pyrocatechol과 pyruvate가 고갈되지 않도록 간헐적으로 첨가하면서 효소반응을 수행한 결과, 24시간 만에 85.2%의 수율로 31.6g/ℓ의 3,4-dihydroxyphenyl-L-alanine를 생산할 수 있었다. By using the β-tyrosinase of Citrobacter freundii KCTC2006, which was cloned and overexpressed in Escherichia coli, 3,4-dihydroxy phenyl-L-alanine (L-DOPA) was synthesized efficiently from pyrocatechol, sodium pyruvate, and ammonium acetate. Optimal temperature and pH for the reaction were determined to be about 18℃ and 8.5, respectively. The effects of substrate concentrations were also examined at different concentrations of ammonium acetate, sodium pyruvate, and pyrocatechol. Ammonium acetate and sodium pyruvate increased the reaction rate until the concentrations reached to 300 mM and 50 mM, respectively. Although pyrocatechol showed the optimal concentration at 20 mM, it was controlled between 20 mM and 50 mM to avoid the depletion of substrate during the enzymatic synthesis. Based on above results, a reaction medium for the production of L-DOPA was prepared and incubated with 1 unit/㎖ of β-tyrosinase. Pyrocatechol and sodium pyruvate was added to the reaction solution intermittently to avoid the substrate depletion during the enzymatic reaction. After 24 hour of reaction, 31.6 g/ℓ L-DOPA was accumulated in the reaction solution as soluble and precipitated ones and the conversion yield was about 85.2%.
배합사료의 단백질 및 지질 함량이 종어L(eiocassis longirostris Gunther) 치어의 성장과 체성분에 미치는 효과
임상구 ( Sang Gu Lim ),한형균 ( Hyoung Kyun Han ),방인철 ( In Chul Bang ),최진 ( Jin Choi ),이상민 ( Sang Min Lee ) 한국수산과학회 2013 한국수산과학회지 Vol.46 No.4
We ran a feeding trial to determine optimal dietary protein and lipid levels for growth of juvenile long snout bullhead Leiocassis longirostris Gunther. Eight experimental diets (P20L7, P20L14, P30L7, P30L14, P40L7, P40L14, P50L7 and P50L14) were formulated to contain 20%, 30%, 40% or 50% protein combined with either 7% or 14% lipid. Three replicate groups of fish (mean mass: 3.9 g/fish) were fed one of the experimental diets ad libitum for 8 weeks. Survival of fish fed the P20L14 diet was lower than that of fish fed the P40L14, P50L7 and P50L14 diets. Growth of fish fed diets containing 7% lipid increased with increasing protein level (up to 50% protein); growth of fish fed diets containing 14% lipid increased with increasing protein level (up to 30% protein). The feed efficiency of fish fed a diet with 50% protein and 7% lipid was higher than that of other groups. Whole body moisture and lipid contents were affected by dietary lipid level but not by dietary protein level. The crude lipid contents of fish fed 14% lipid diets were higher than those fed 7% lipid diets across all protein levels (other than the 50% level). Thus, under our experimental conditions, an increase in dietary protein level improved growth and feed efficiency of fish; a diet containing 50% protein with 7% lipid was optimal for growth and effective feed utilization in juvenile long snout bullhead.
Durability Study of Steel Slag as Catalyst for Steam Reforming Reaction of Tar
( Sung Bang Nam ),( Ho-jin Sung ),( Yeong-su Park ),( Dong-ju Kim ),( Jae-hoi Gu ) 한국폐기물자원순환학회(구 한국폐기물학회) 2015 한국폐기물자원순환학회 3RINCs초록집 Vol.2015 No.-
As one of the promising methods for reduction of tar on the gasification system, the catalytic steam reforming reaction has been employed over iron oxide based catalyst. In the present study, we investigated the suitability of steel slag, which is composing iron oxide, as catalyst for steam reforming reaction of benzene as model tar. The initial catalytic activity of steel slag was enhanced when it has been treated using methods such as alkali treatment, alkali hydrothermal treatment and hydrothermal treatment. By comparing performance of treated samples, we obtained highest carbon conversion over hydrothermally treated steel slag, which is 59% higher than homogeneous reaction condition at 900℃. In addition, its catalytic activity was maintained during the durability test at 900 ℃ for 36h.
(Sang Suk Kim,(Jung Hee Bang,(Chang Gu Hyun,(Joo Woo Kim,(Jae Jin Han,(Joo Won Suh 한국응용생명화학회 2000 Journal of Applied Biological Chemistry (J. Appl. Vol.43 No.3
A novel 6-deoxyhexose biosynthetic gene cluster different from the one for the biosynthesis of streptomycin was isolated from Streptomyces griseus using specifically designed PCR primers to compare the sequence of known dTDP-glucose synthase genes. We clon