• Journal of Life Science
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• v.18 no.12
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• pp.1625-1630
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• 2008

A microorganism capable of producing high level of poly-3-hydoxybutyrate (PHB) from xylose was isolated from soil. The isolated strain J-65 was identified as Bacillus megaterium based on the morphological, biochemical and molecular biological characteristics. The optimum temperature and pH for the growth of B. megaterium J-65 were $37^{\circ}C$ and 8.0, respectively. The optimum medium composition for the cell growth was 2% xylose, 0.25% $(NH_4)_2SO_4$, 0.3% $Na_2HPO_4{\cdot}12H_2O$, and 0.1% $KH_2PO_4$. The optimum condition for PHB accumulation was same to the optimum condition for cell growth. Copolymer of ${\beta}$-hydroxybutyric and ${\beta}$-hydroxyvaleric acid was produced when propionic acid was added to shake flasks containing 20 g/l of xylose. Fermenter culture was carried out to produce the high concentration of PHB. In batch culture, cell mass was 9.82 g/l and PHB content was 35% of dry cell weight. PHB produced by B. megaterium J-65 was identified as homopolymer of 3-hydoxybutyric acid by GC and NMR.

• The Journal of the Petrological Society of Korea
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• v.4 no.1
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• pp.31-48
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• 1995

The Jurassic Kwanaksan stock, so far known to be composed of biotite granite only, has the mineral assemblage of quartz+K-feldspar+plagioclase+biotite${\pm}$gernet. The lithology of the stock is classified as alkali feldspar granite by their mode and plagioclase compositions (An<5). Subsolvus feldspars, rather early crystallization of biotite, and shallow emplacement depth estimated from Q-Ab-Or diagram suggest hydrous nature of the magma, which contrasts with anhydrous A-type like geochemistry described below. Major and trace element compositions of the Kwanaksan stock are distinct from those of the adjacent Seoul batholith, suggesting a genetic difference between the two, The Kwanaksan stock shows geochemical characteristics similar to A-type granite in contrast to most other Mesozoic granites in Korea, in that it has high $SiO_2$(73~78wt%), $Na_2O+K_2O$, Ga(27~47 ppm). Nb(22~40 ppm), Y(48~95 ppm), Fe/Mg and Ga/Al, and low CaO(<0.51 wt%). Ba (8~75 ppm) and Sr(2~23 ppm). However, it has lower Zr and LREE and higher Rb(384~796 ppm) than typical A-type granite. LREE-depleted rare earth element pattern with strong negative Eu anomaly of previous studies is reinterpreted as representing source magma characteristics. The residual material during partial melting is not compatible with pyroxenes, amphibole or garnet, while significant amount of plagioclase is required. Similarity of geochemistry of the Kwanaksan stock to A-type granite suggests the origin of the stock has a chose relationship with that of A-type granite. These observations lead us to propose that the Kwanaksan stock was formed by partial melting of felsic source rock.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.33 no.3
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• pp.84-99
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• 2001

This study was carried out to acquire basic data necessary for the use of rice-straw chemical pulp. It investigated the proper bleaching conditions when rice-straw chemical pulp(alkaline sulfite-${Na_2}{S_2}{O_4}$) was bleached using the various kinds of bleaching agents by the two-stages bleaching methods. And, physical properties of pulps bleached with eight kinds of two-stages bleaching methods were tested. The results of this study were as follow; 1. The first-stage bleaching was conducted under the proper conditions with chlorine(C). And then, the proper conditions related to the calcium chlorite(H), hydrogen peroxide(P) and sodium hydrosulfite(Y) bleaching as the second-stage bleaching were investigated. The proper conditions of CH stage were determined to be 0.3% concentration of calcium chlorite, $30^{\circ}C$ of reaction temperature and 20min. of reaction time. For CP stage, the proper conditions of concentration of hydrogen peroxide, reaction temperature and reaction time were 1.5%, $60^{\circ}C$ and 90min., respectively. And for CY stage, the proper conditions were 0.5% concentration of sodium hydrosulfite, $40^{\circ}C$ of reaction temperature and 90min. of reaction time. 2. The first-stage bleaching was conducted under the proper conditions with chlorine dioxide(D). And then, the proper conditions related to the calcium chlorite(H), hydrogen peroxide(P) and sodium hydrosulfite(Y) bleaching as the second-stage bleaching were investigated. The proper conditions of DH stage were determined to be 0.5% concentration of calcium chlorite, $25^{\circ}C$ of reaction temperature and 5min. of reaction time. For DP stage, the proper conditions of concentration of hydrogen peroxide, reaction temperature and reaction time were 1.0%, $70^{\circ}C$ and 90min., respectively. And for DY stage, the proper conditions were 0.3% concentration of sodium hydrosulfite, $50^{\circ}C$ of reaction temperature and 20min. of reaction time. 3. The first-stage bleaching was conducted under the proper conditions with calcium chlorite(H). kAnd then, the proper conditions related to the hydrogen peroxide(P) and sodium hydrosulfite(Y) bleaching as the second-stage bleaching were investigated. The proper conditions of HP stage were determined to be 0.3% concentration of hydrogen peroxide, $30^{\circ}C$ of reaction temperature and 60min. of reaction time. For HY stage, the proper conditions of concentration of sodium hydrosulfite, reaction temperature and reaction time were 2.5%, $60^{\circ}C$ and 30min., respectively. 4. When the rice-straw chemical pulps were bleached with eight kinds of two-stages bleaching methods in the proper conditions mentioned above, respectively, the final brightnesses after CH, CP, CY, DH, DP, DY, HP, and HY bleachings were 62.0, 74.3, 61.4, 58.9, 66.9, 62.9, 50.4 and 60.1, respectively. And strengthes of pulps bleached with DP and DH methods were comparatively higher than those of pulps bleached with other bleaching methods.

• Journal of Animal Environmental Science
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• v.15 no.3
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• pp.189-198
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• 2009

This survey was conducted to investigate the situation of housing type in poultry farms in Korea. The number surveyed among the farm size over 30,000 heads was 1,965 farms. Poultry housing types of windowless, open sided, vinyl house type were 19.0, 47.7, 19.8%, respectively. Waterers of nipple, bell, and 8 feet trough used in smaller than 50,000 heads of poultry farm were 40.6, 11.3 and 42.8%, respectively. But the bigger farm in the farm size of over 100,000 heads used more nipple waterer. Feeders of disk, hopper and chain used in poultry farm were 54.5, 16.3, 15.8%, respectively. Manure collecting system of scraper and belt was 29.4, 71.5 %, respectively. Ventilation systems of natural ventilation, natural + mechanical ventilation, mechanical ventilation were 40.5, 39.8, 20.7%, respectively.

• Clinical and Experimental Pediatrics
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• v.49 no.3
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• pp.317-325
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• 2006

Purpose : This study was carried out to elucidate the effects of nitric oxide synthase(NOS) inhibitor, NG-monomethyl-L-arginine(L-NMMA) and nitric oxide precursor, L-arginine(L-Arg) on cerebral hemodynamics and energy metabolism during reoxygenation-reperfusion(RR) after hypoxia-ischemia(HI) in newborn piglets. Methods : Twenty-eight newborn piglets were divided into 4 groups; Sham normal control(NC), experimental control(EC), L-NMMA(HI & RR with L-NMMA), and L-Arg(HI & RR with L-Arg) groups. HI was induced by occlusion of bilateral common carotid arteries and simultaneously breathing with 8 percent oxygen for 30 mins, and followed RR by release of carotid occlusion and normoxic ventilation for one hour. All groups were monitored with cerebral hemodynamics and cytochrome $aa_3$ (Cyt $aa_3$) using near infrared spectroscopy(NIRS). $Na^+$, $K^+$-ATPase activity, lipid peroxidation products, and tissue high energy phosphate levels were determined biochemically in the cerebral cortex. Results : In experimental groups, mean arterial blood pressure, $PaO_2$, and pH decreased, and base excess and blood lactate level increased after HI compared to NC group(P<0.05). These variables subsequently returned to baseline after RR except pH. There were no differences among the experimental groups. In NIRS, oxidized hemoglobin($HbO_2$) decreased and hemoglobin(Hb) increased during HI(P<0.05) but returned to base line immediately after RR; 40 min after RR, the $HbO_2$ had decreased significantly compared to NC group(P<0.05). Changes of Cyt $aa_3$ decreased significantly compared to NC after HI and recovered at the end of the experiment. Significantly reduced cerebral cortical cell membrane $Na^+$, $K^+$-ATPase activity and increased lipid peroxidation products(P<0.05) were not improved with L-NMMA or L-Arg. Conclusion : These findings suggest that NO is not involved in the mechanism of HI and RR brain damage during the early acute phase of RR.

• Journal of Microbiology and Biotechnology
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• v.22 no.10
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• pp.1412-1422
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• 2012

The aim of this work was to establish the optimal conditions for production of carboxymethylcellulase (CMCase) by a newly isolated marine bacterium using response surface methodology (RSM). A microorganism producing CMCase, isolated from seawater, was identified as Cellulophaga lytica based 16S rDNA sequencing and the neighborjoining method. The optimal conditions of rice bran, ammonium chloride, and initial pH of the medium for cell growth were 100.0 g/l, 5.00 g/l, and 7.0, respectively, whereas those for production of CMCase were 79.9 g/l, 8.52 g/l, and 6.1. The optimal concentrations of $K_2HPO_4$, NaCl, $MgSO_4{\cdot}7H_2O$, and $(NH_4)_2SO_4$ for cell growth were 6.25, 0.62, 0.28, and 0.42 g/l, respectively, whereas those for production of CMCase were 3.72, 0.54, 0.70, and 0.34 g/l. The optimal temperature for cell growth and the CMCase production by C. lytica LBH-14 were $35^{\circ}C$ and $25^{\circ}C$, respectively. The maximal production of CMCase under optimized condition for 3 days was 110.8 U/ml, which was 5.3 times higher than that before optimization. In this study, rice bran and ammonium chloride were developed as carbon and nitrogen sources for the production of CMCase by C. lytica LBH-14. The time for production of CMCase by a newly isolated marine bacterium with submerged fermentations reduced to 3 days, which resulted in enhanced productivity of CMCase and a decrease in its production cost.

• Environmental Engineering Research
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• v.10 no.3
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• pp.138-143
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• 2005

Laboratory batch experiments were conducted to evaluate the Fenton degradation rates of phenanthrene. Fenton reactions for the degradation of phenanthrene were carried out with aqueous and slurry phase, to investigate the effects of sorption of phenanthrene onto solid phase. Various types of surfactants and electrolyte solutions were used to evaluate the effects on the phenanthrene degradation rates by Fenton's reaction. A maximum 90% removal of phenanthrene was achieved in aqueous phase with 0.9% of $H_2O_2$ and 300 mg/L of $Fe^{2+}$ at pH 3. In aqueous phase reaction, inhibitory effects of synthetic surfactants on the removal of phenanthrene were observed, implying that surfactant molecules acted as strong scavenger of hydroxyl radicals. However, use of $carboxymethyl-{\beta}-cyclodextrin$ (CMCD), natural surfactant, showed a slight enhancement in the degradation of phenanthrene. It was considered that reactive radicals formed at ternary complex were located in close proximity to phenanthrene partitioned into CMCD cavities. It was also show that Fenton degradation of phenanthrene were greatly enhanced by addition of NaCl, indicating that potent radical ion ($OCI^-$) played an important role in the phenanthrene degradation, although chloride ion might be acted as scavenger of radicals at low concentrations. Phenanthrene in slurry phase was resistant to Fenton degradation. It might be due to the fact that free radicals were mostly reacting with dissolved species rather than with sorbed phenanthrene. Even though synthetic surfactants were added to increase the phenanthrene concentration in dissolved phase, low degradation efficiency was obtained because of the scavenging of radicals by surfactants molecules. However, use of CMCD in slurry phase, showed a slight enhancement in the phenanthrene degradation. As an alternative, use of Fenton reaction with CMCD could be considered to increase the degradation rates of phenanthrene desorbed from solid phase.

• Journal of the Mineralogical Society of Korea
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• v.25 no.4
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• pp.271-282
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• 2012

We explore the effect of removal of organic ligand on the atomic configurations around oxygen in hydroxyl groups in amorphous silica gel (synthesized through hydrolysis of $SiCl_4$ in diethyl-ether) using high resolution $^{17}O$ solid state NMR spectroscopy. $^1H$ and $^{29}Si$ MAS NMR spectra for amorphous silica gel showed diverse hydrogen environments including water, hydroxyl groups (e.g., hydrogen bonded silanol, isolated silanol), and organic ligands (e.g., alkyl chain) that may interact with surface hydroxyls in the amorphous silica gel, for instance, forming silica-organic ligand complex (e.g., Si-$O{\cdots}R$). These physically and chemically adsorbed organic ligands were partly removed by ultrasonic cleaning under ethanol and distilled water for 1 hour. Whereas $^{17}O$ MAS NMR spectra with short pulse length ($0.175{\mu}s$) at 9.4 T and 14.1 T for as-synthesized amorphous silica gel showed the unresolved peak for Si-O-Si and Si-OH structures, the $^{17}O$ MAS NMR spectra with long pulse length ($2{\mu}s$) showed the additional peak at ~0 ppm. The peak at ~0 ppm may be due to Si-OH structure with very fast relaxation rate as coupled to liquid water molecules or organic ligands on the surface of amorphous silica gel. The observation of the peak at ~0 ppm in $^{17}O$ MAS NMR spectra for amorphous silica gel became more significant as the organic ligands were removed. These results indicate that the organic ligands on the surface of amorphous silica gel interact with oxygen atoms in Si-OH and provide the information about atomic structure of silanol and siloxane in amorphous silica gel. The current results could enhance the understanding of dehydration mechanism of diverse silicates, which is known as atomic scale origins of intermediate depth (approximately, 70~300 km) earthquakes in subduction zone.

• Journal of Life Science
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• v.12 no.3
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• pp.242-249
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• 2002

The optimal culture conditions in 500$m\ell$ flask suture, 5$\ell$ jar fermenter and 2,000 $\ell$ large stale culture were investigated to maximize the production of antibiotic on Rhizoctonia solani AC4, the causal agent of vegetables damping-off, by the strain Bacillus ehimensis YJ-37. Starch (1.5%) as a carbon source, peptone (0.6%) as a nitrogen source and MgC1$_2$(0.15%) as a metal ion in the medium containing N $a_2$HP $O_4$(0.3%) showed the highest production of the antibiotic(s) in a rotary shake (200 rpm). Optimal initial pH of the culture medium, culture temperature and culture time for the antibiotic(s) production were pH 8.0, 32$^{\circ}C$ and 54hrs, respertively. Under the optimal renditions in flask culture, cell growth and antifungal activity (clear zone size) were 1.42 $\times$ 10$^{8}$ cfu/$m\ell$ (21g-DCW/ $\ell$) and 13.9 mm, respectively. In 5 $\ell$ jar fermenter (medium 3 $\ell$), optimal air flow, agitation speed and culture time for the antibiotic(s) production were 2 vvm, 200 rpm and 48hrs, respectively. Under the optimal conditions in 5 $\ell$ jar fermenter, tell growth and antifungal activity were 2.06 $\times$ 10$^{8}$ cfu/$m\ell$ (30g-DCW/ $\ell$) and 13.4 mm, respectively. Under the culture conditions of air flow (30 vvm) and agitation speed (200 rpm) at 32$^{\circ}C$ for 10 days in 2,000 $\ell$ large scale culture (medium 1,800 $\ell$, pH 8.0), cell growth and antifungal activity were 0.81$\times$10$^{8}$ cfu/$m\ell$ (12g-DCW/ $\ell$) and 8.6 mm, respectively.

• Journal of the Korean Society of Costume
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• v.49
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• pp.49-63
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• 1999

This research utilized the Energy Dispersive X-ray Spectroscopy(EDS) and the Inductively Coupled Plasma Mass Spectrometry in the analysis of chemical elements present among the textiles exhumed from Kupori Hwasung-kun Kyunggi-do. The two research objectives were: first to examine the elements present and their percent presence in Kupori samples: second to investigate whether the elements are part of mordant substances which could have been used when dyeing the KUpori textiles in the past. To meet such research purposes standard silk fabric was dyed with Sophorajaponica using alum and iron mordants. For alum mordant unpurified general alum and potassium aluminum sulfate(AlK(SO4)2). iron sulfate(FeSO4·7H2O) were used, From the results of EDS and ICP-Mass analysis the following conclusions were drawn. 1 According to the EDS analysis 9 elements Ca, S, Al, Si, K, Fe, P, Mg and Na were detected. 2. ICP-Mass result of the mordant chemicas showed high amount of A, Al and k present in alum mordants and S and Fe present in iron mordants. 3. Comparison of the ICP-Mass results of the mordant chemicals and those of the standard dyed samples suggested that the amount presence of Al and Fe is a strong indication of the usage of alum and iron mordants respecticely in an unknown dyed textile. 4, In the washed Kupori textiles Fe showed a relatively higher rate of presence in the samples Therefore it can be conjectured that those Kupori textiles were dyed with iron mordant based on the result of the above number 3. 5. It is probable that the other elements detected from the Kupori samples were incorporated into the textiles as part of the soil debris produced from the degradation of the dead within the coffin or the earth debris. They can also be part of the inorganic compounds inherent in the silk textiles themselves before dyed. 6. Among the elements it is likely that Ca which showed a high degree of presence among the unwashed samples was part of the inorganic compound inferent in the silk textiles.