• Microbiology and Biotechnology Letters
• /
• v.44 no.4
• /
• pp.470-478
• /
• 2016

A bacterium producing a large amount of chitinolytic enzyme was isolated from the intestinal tract of earthworm. The isolate was identified as Bacillus licheniformis by 16S ribosomal RNA analysis and designated as B. licheniformis GA9. The enzyme was purified by 40-60% ammonium sulfate precipitation, diethyl-aminoethyl groups exchange chromatography, and gel filtration chromatography. The molecular weight was estimated to be 52.1 kDa and the N-terminal amino acid sequence was D-S-G-K-N-G-K-I-I-R-Y-YP-I-R. The optimum activity of the purified chitinolytic enzyme was shown at pH 5.0 and $40^{\circ}C$, and the enzyme was stable in the ranges of $20-50^{\circ}C$ and pH 5.0-6.0. Enzyme activity was increased by $Co^{2+}$, while it was inhibited by $Cu^{2+}$ and $Fe^{2+}$. But it was recovered by chelating metals with ethylenediaminetetraacetic acid. The $K_m$ and $V_{max}$ values of the purified enzyme were 4.02 mg/ml and 0.52 mg/min, respectively. The chitinolytic enzyme characterized in this study has potential applications in areas such as biotechnology, biomedicine, agriculture, and nutrition.

• Journal of Plant Biology
• /
• v.35 no.3
• /
• pp.191-195
• /
• 1992

Changes in activity of gibberellin C20-hydroxylase which converts $[^{14}C]GA_{12}\;to\;GA_{l5}$ were studied during seed maturation using the partially purified enzyme preparations of two cultivars, Kentucky Wonder (normal) and Masterpiece (dwarf) of Phaseolus vulgaris. The preparations obtained by methanol precipitation and hydrophobic interaction chromatography efficiently converted; $GA_{l2}\;to\;GA_{4},\;via\;GA_{15},\;GA_{24}\;and\;GA_{9};\;GA_{20}\;to\;GA_{1},\;GA_{5}\;and\;GA_{6}$. The activities of C20-hydroxylase which converts $GA_{l2}\;to\;GA_{l5}$ were almost the same in both cultivars. The C20-hydroxylase activity per protein reached a maximum at the very early immature seed stage, followed by a subsequent rapid decrease during seed maturation, whereas the enzyme specific activity per seed reached a maximum at 21 days after flowering, and showed a similar fiuctuation to that of the 313-hydroxylase which converts $GA_{20}\;to\;GA_{l}$ during seed maturation.ration.

• Journal of Life Science
• /
• v.12 no.3
• /
• pp.281-287
• /
• 2002

Quinone reductase was purified to homogeneity from bovine liver and the purified enzyme catalyzed the reduction of phenanthrenequinone as well as benzo- and naphthoquinones. The enzyme catalyzed the biotransformation of arylnitroso nitroso compound and the reaction product was identified by TLC, GC, CC-MS and NMR. The reaction was almost entirely inhibitable by Cibacron blue 3GA or dicumarol, potent inhibitors of mammalian quinone reductase.

• Proceedings of the Membrane Society of Korea Conference
• /
• 1994.03a
• /
• pp.97-112
• /
• 1994

이산화탄소의 분리회수가 필요한 공정은 지금까지 천연가스정제, 암모니아 제조시 수소정제, 매립지 가스, Enhanced oil recovery (EOR), Bio 가스정제 등이 있었으며 최근에는 지구온난화의 주원인인 CO$_{2}$를 배출가스(Flue gas)부터 분리하는 것이 중요한 과제로 대두되고 있다. 본 논문에서는 지구협약에 의해 방출규제가 따를것으로 예상되는 Flue gas에 포함된 CO$_{2}$의 배출제어를 중심으로 분리막을 이용한 이산화탄소 분리회수 기술을 살펴보고자 한다.

• Membrane Journal
• /
• v.4 no.2
• /
• pp.78-84
• /
• 1994

이산화탄소의 분리회수가 필요한 공정은 지금까지 천연가스정제, 암모니아 제조시 수소정제, 매립지 가스, Enhanced oil revovery (EOR), Bio 가스정제 등이 있었으며, 최근에는 지구온난화의 주원인인 $CO_2$를 배출가스(Flue gas)로부터 분리하는 것이 중요한 과제로 대두되고 있다. 본 논문에서는 지구협약에 의해 방출규제가 따를 것으로 예상되는 Flue gas에 포함된 $CO_2$의 배출제어를 중심으로 분리막을 이용한 이산화탄소 분리회수기술을 살펴보고자 한다.

• Journal of Plant Biology
• /
• v.35 no.3
• /
• pp.185-190
• /
• 1992

Changes in activity of gibberellin $3{\beta}-hydroxylase$ which converts $[^3H]GA_{20}\;to\;GA_1$ were studied during seed maturation using partially purified enzyme preparations of two cultivars, Kentucky Wonder (normal) and Masterpiece (dwarf) of Phaseolus vulgaris. The specific activity of $3{\beta}-hydroxylase$ per seed reached maximum at 21 days after flowering and subsequently decreased during seed maturation in both cultivars. The ratios of conversion of $[17-^{13}C,\;^3H_2]GA_{20}\;to\;GA_1.\;GA_5,\;and\;GA_6$ by the same amount of $3{\beta}-hydroxylase$ were almost identical. Epoxidation of $GA_5\;to\;GA_6$ is also catalyzed by the partially purified $3{\beta}-hydroxylase$ preparation(Kobayashi et aI., 1991) and the conversion was inhibited by the substrates of $3{\beta}-hydroxylase$. These results suggest that the same enzyme might catalyze $3{\beta}-hydroxylase{\;}of{\;}GA_{20}\;to\;GA_1$ and epoxidation of $GA_5\;to\;GA_6$..

• Korean Journal of Plant Resources
• /
• v.14 no.1
• /
• pp.38-42
• /
• 2001

This study was conducted to stable direct sowing cultivation with seedling growth promotion by plant growth regulator treatment in onion seed(Allium cepa L.) The emergence percentage of soaked seed in BA, GA$_3$, and kinetin solution were higher than control seed, and those were 93.0, 94.3, 93.8%, respectively. The plant height was significant elongation in growth regulators treated seed, and those effects were high GA$_3$, kinetin and BA in the order, and the extend were high as increasing the growth regulator solution concentration in GA$_3$ and BA, and that was reverse in kinetin. The No. of leaf was increased in growth regulators treated seed, and the extend were similar among the growth regulators. The No. of root was increased significantly in growth regulators treated seed, and the extend were high in GA$_3$, BA and kinetin in the order.

• Resources Recycling
• /
• v.23 no.1
• /
• pp.25-32
• /
• 2014

The purpose of this research is to develop a process and a system to collect, purify and reuse the residual quantity of trimethylgallium, used as a raw material, upon GaN epitaxial growth for LED from a metal organic chemical vapor deposition(MOCVD) equipment. This research reviews whether TMGa collected from the process can be used through a chemical and structural characteristics evaluation. As a result of analyzing the purity using ICP-MS and ICP-AES, 7N high purity (99.99999%) of TMGa was obtained. According to checking the structural change of TMGa through NMR analysis, TMGa having pure $(CH_3)_3Ga$ structure was obtained without structural change. For reliability review of the collected TMGa, u-GaN was deposited using the MOCVD process and an structural, optical and electrical characteristics evaluation was conducted. As a result, it was found out that the reuse was possible.

• Analytical Science and Technology
• /
• v.8 no.2
• /
• pp.117-124
• /
• 1995

To Purify hemoproteins showing from 218nm absorbance, crude liver extract of human with hepatocirrhosis was treated with Triton N-101. Hemoproteins were purified by modification of Mohamed's method. This crude extract was applied to Octyl-Sepharose CL-4B column and the step elution was performed with 0.06% Lubrol PX and 0.25% Lubrol PX. The absorption of effluents were examined at 418nm and two peaks were appeared(Fig. 2). Hemoproteins were purified from Hyydroxyapatite and DEAE-Sephadex A-25 columns which the first peak was applied to(Fig. 3, 4). In death with suddenly, purified hemoproteins with 62 and 45kDa were obtained from 12.5% SDS-PAGE. In death with hepatocirrhosis, purified hemoprotein with 54kDa was obtainded from 12.5% SDS-PAGE(Fig. 5). Cytochrome P450 was purified to a specific content of 20.8nmol/mg protein with a recovery of about 4.1%. Absorbance maximum of these hemoproteins were 446nm at UV spectruum(Fig. 6).

• Resources Recycling
• /
• v.24 no.4
• /
• pp.50-55
• /
• 2015

In this study, we have investigated solvent extraction of Ga and recovery of high pure Ga solution from MOCVD dust for manufacturing of LED chip. Effect of extractan, concentration of extractant were examined for choosing the more effective extractant and high pure Ga solution was fabricated by multi-stage extraction/stripping process. For extraction/separation of Ga based on the analysis of raw-material in previous study, 3 different extractants PC 99A, DP-8R, Cyanex 272 has been investigated and the extraction efficiency of 1.5 M Cyanex 272 was 43.8%. It was conformed that extraction efficiency of Ga was 83% in multi-stage extraction and 5N high purity Ga stripping solution without impurities also obtained.