• Journal of Microbiology and Biotechnology
• /
• v.20 no.10
• /
• pp.1378-1385
• /
• 2010

A novel agarolytic bacterium, KY-YJ-3, producing extracellular agarase, was isolated from the freshwater sediment of the Sincheon River in Daegu, Korea. On the basis of Gram-staining data, morphology, and phylogenetic analysis of the 16S rDNA sequence, the isolate was identified as Cellvibrio sp. By ammonium sulfate precipitation followed by Toyopearl QAE-550C, Toyopearl HW-55F, and MonoQ column chromatographies, the extracellular agarase in the culture fluid could be purified 120.2-fold with a yield of 8.1%. The specific activity of the purified agarase was 84.2 U/mg. The molecular mass of the purified agarase was 70 kDa as determined by dodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The optimal temperature and pH of the purified agarase were $35^{\circ}C$ and pH 7.0, respectively. The purified agarase failed to hydrolyze the other polysaccharide substrates, including carboxymethyl-cellulose, dextran, soluble starch, pectin, and polygalacturonic acid. Kinetic analysis of the agarose hydrolysis catalyzed by the purified agarase using thin-layer chromatography showed that the main products were neoagarobiose, neoagarotetraose, and neoagarohexaose. These results demonstrated that the newly isolated freshwater agarolytic bacterium KY-YJ-3 was a Cellvibrio sp., and could produce an extracellular ${\beta}$-agarase, which hydrolyzed agarose to yield neoagarobiose, neoagarotetraose, and neoagarohexaose as the main products.

• Journal of Ocean Engineering and Technology
• /
• v.25 no.5
• /
• pp.15-20
• /
• 2011

This study carried out a series of experiments involving impact tests (Drop Weight type & Charpy type with a standard specimen and newly designed I-type specimen), hardness tests, and fracture surface observations of French-made roll shell steel (F), abnormal roll shell steel (M), reheated roll shell steel (R), and S25C steel under heat treatment conditiAn experimental study was carried out to study the solid-liquid mixture upward hydraulic transport of solid particles in vertical and inclined annuli with a rotating inner cylinder. The lift forces acting on a fluidized particle play a central role in many important applications such as the removal of drill cuttings in horizontal drill holes, sand transport in fractured reservoirs, sediment transport, the cleaning of particles from surfaces, etc. In this study a clear acrylic pipe was used to observe the movement of solid particles. Annular velocities varied from 0.4 to 1.2 m/s. The effect of the annulus inclination and drill pipe rotation on the carrying capacity of a drilling fluid, particle rising velocity, and pressure drop in a slim hole annulus were measured for fully-developed flows of water and aqueous solutions of CMC (sodium carboxymethyl cellulose) and bentonite. The rotation of the inner cylinder was efficient at carrying particles to some degree. For a higher particle volume concentration, the hydraulic pressure loss of the mixture flow increased because of the friction between the wall and solids or between solids.

• KSBB Journal
• /
• v.7 no.1
• /
• pp.59-65
• /
• 1992

Hydrodynamics and mixing characteristics such as circulation time, mixing time, circulation velocity and axial dispersion coefficient were investigated using highly viscous pseudoplastic solutions of carboxymethyl cellulose(CMC) in an external circulation loop air-lift reactor with 13$\ell$ working volume. The superficial gas velocity was changed from 1.9 to 6.2cm/s and CMC concentration from 0 to 1.0wt%. The theoretical model based on the pressure balance is developed mathematically to predict liquid circulation velocity. Gas hold-up, circulation velocity and axial dispersion coefficient of liquid phase increased with increasing gas velocity and decreased slightly with increasing liquid viscosity. Mixing time and circulation time decreased with increasing gas velocity and increased with increasing liquid viscosity. Experimental data on liquid circulation velocity were in good agreement with the predicted values.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.33 no.3
• /
• pp.181-185
• /
• 2020

Hazardous and noxious substance (HNS) detection sensors were fabricated using multi-walled carbon nanotubes (MWCNTs) and various binder materials for ion batteries. To obtain uniformly printed films, the printing precision according to the substrate cleaning method was monitored, and the printing paste mixing ratio was investigated. Binders were prepared using styrene butadiene rubber + carboxymethyl cellulose (SBR+CMC), polyvinylidene fluoride + n-methyl-2-pyrrolidene (PVDF+NMP), and mixed with MWCNTs. The surface morphology of the printed films was examined using an optical microscope and a scanning electron microscope, and their electrical properties are investigated using an I-V sourcemeter. Finally, sensing properties of MWCNT printed films were measured according to changes in the concentration of the chemical under the various applied voltages. In conclusion, the MWCNT printed films made of (SBR+CMC) were found to be feasible for application to the detection of hazardous and noxious chemicals spilled in seawater.

• Journal of Microbiology and Biotechnology
• /
• v.22 no.12
• /
• pp.1705-1713
• /
• 2012

A gene encoding ${\beta}$-glucosidase was cloned from Weissella cibaria 37, an isolate from human feces. Sequence analysis showed that the gene could encode a protein of 415 amino acids in length, and the translated amino acid sequence showed homology (34-31%) with glycosyl hydrolase family 1 ${\beta}$-glucosidases. The gene was overexpressed in E. coli BL21(DE3) using pET26b(+) and a 50 kDa protein was overproduced, which matched well with the calculated size of the enzyme, 49,950.87 Da. Recombinant ${\beta}$-glucosidase was purified by using a his-tag affinity column. The purified ${\beta}$-glucosidase had an optimum pH and a temperature of 5.5 and $45^{\circ}C$, respectively. Among the metal ions (5mM concentration), $Ca^{2+}$ slightly increased the activity (108.2%) whereas $Cu^{2+}$ (46.1%) and $Zn^{2+}$ (56.7%) reduced the activity. Among the enzyme inhibitors (1 mM concentration), SDS was the strongest inhibitor (16.9%), followed by pepstatin A (45.2%). The $K_m$ and $V_{max}$ values of purified enzyme were 4.04 mM and 0.92 ${\mu}mol/min$, respectively, when assayed using pNPG (p-nitrophenyl-${\beta}$-D-glucopyranoside) as the substrate. The enzyme liberated reducing sugars from carboxymethyl cellulose (CMC).

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.42 no.5
• /
• pp.74-82
• /
• 2010

Curtain stability without curtain contraction is critical for a successful operation in curtain coating, and this can be influenced by the change in particle dynamics and rheological properties of coating colors. In this study, polyvinyl alcohol (PVA) and carboxymethyl cellulose (CMC) were added to control the rheology of GCC based curtain coating colors. Surface tension was increased slightly with increasing content of cobinder. Shear-thinning of viscosity was more pronounced for the CMC containing GCC coating colors. Complex modulus decreased when small amount of PVA was used as a cobinder, but it increased in other coating colors. Extensional viscosity was increased with increasing of the cobinder content, but CMC was more effective. Results indicate that pigment interaction with PVA is different from that with CMC. Dispersibility of coating colors was improved due to steric stabilization when small amounts of PVA was used, but flocculation occurred by bridging when the amount of PVA was increased. Dispersibility of coating colors was improved when small amount of CMC was added, while flocculation was observed by depletion effect when the concentration of CMC was increased in coating colors. Addition of cobinders at proper levels gave positive effects both in rheological properties and curtain stability. On the other hand, excessive amount of cobinders caused particle flocculation and this resulted in rheological and curtain stablity problems.

• Korean journal of food and cookery science
• /
• v.12 no.2
• /
• pp.193-199
• /
• 1996

Effects of addition of various additives, sucrose fatty acid ester 1170 (SE), carboxymethyl cellulose (CMC) and soy bean oil (SO) on textural characteristics for untreated and defatted corn and mung bean starch gels stored at room temperature for 24 hrs and 72 hrs were studied. In sensory and instrumental characteristics of starch gels with additives (0.5% for starch basis), the acceptability was highly correlated with cohesiveness and bend property of starch gels stored 24 hrs and springiness, cohesiveness, color, smoothness, bend property, hardness and clarity of starch gels stored 72 hrs. Regardless of adding additives, textural characteristics of defatted corn starch gels showed somewhat higher values than that of com starch gels. The acceptability of starch gels with additives was somewhat lowered in all the cases, which showed highly correlated in cohesiveness for 24 hrs and springiness for 72 hrs. Instrumental characteristics were similar to those of sensory evaluation, which showed no significant difference with additives.

• Journal of Nutrition and Health
• /
• v.31 no.7
• /
• pp.1093-1099
• /
• 1998

Dioscorea japonica Thunb its effects has been used in f31k remedies f9r various purposes including treatment of diabetes, on hypoglycemic actiity and energy metabolism were investigated. The plant was extracted with methanol(MeOH) and fractionated into four layers hexane, chloroform(CHCI$_3$), butanol(BuOH), and $H_2O$. Diabetes mellitus was induced in male Sprague-Dawley rats by the injection of streptozotocin(STZ) into tail vein at a dose of 45mg/kg body weight(BW). Sprague-Dawley male rats weighing 160-200g were divided into five groups a diabetic control and four experimental groups such as hexane group, CHCl$_3$ group, BuOH group, and $H_2O$ group. The rats of all groups were fed on a AIN-76 diet and the four experimental groups were orally administered each fraction(500mg/kg BW) for 12 days. The diabetic control group was orally administered 5% carboxymethyl cellulose. The body weights were monitored and the concentrations of blood glucose were determined. The levels of glycogen and protein in liver were also measured. The plasma levels of cholesterol, triglyceride (TG), and fee fatty acid(FFA) were also analysed. The body weight gain was higher in the $H_2O$ group than in the control group. Heart weight was significantly reduced by administrations of Dioscorea japonica Thunb. The extents of blood glucose decrement in BuOH and $H_2O$ group were greater than that found in the control group. The muscle protein levels showed significantly higher amounts in all experimental groups. Glycogen levels were higher in the BuOH group than in the control group. The levels of TG were decreased in all experimental groups and the levels of plasma FFA were lower in the BuOH group. The plasma cholesterol levels were not influenced by these four fractions in diabetic rats. These results suggest that the orally administered H2O fraction of Dioscorea japonica Thunb exhibited hypoglycemic effects in STZ induced diabetic rats. (Korean J Nutrition 31(7) : 1093-1099, 1998)

• Journal of Microbiology and Biotechnology
• /
• v.28 no.12
• /
• pp.2036-2045
• /
• 2018

An endo-${\beta}$-1,4-glucanase gene, cel5L, was cloned using the shot-gun method from Bacillus sp.. The gene, which contained a predicted signal peptide, encoded a protein of 496 amino acid residues, and the molecular mass of the mature Cel5L was estimated to be 51.8 kDa. Cel5L contained a catalytic domain of glycoside hydrolase (GH) family 5 and a carbohydrate-binding module family 3 (CBM_3). Chromatography using HiTrap Q and CHT-II resulted in the isolation of two truncated forms corresponding to 50 (Cel5L-p50) and 35 kDa (Cel5L-p35, CBM_3-deleted form). Both enzymes were optimally active at pH 4.5 and $55^{\circ}C$, but had different half-lives of 4.0 and 22.8 min, respectively, at $70^{\circ}C$. The relative activities of Cel5L-p50 and Cel5L-p35 for barley ${\beta}$-glucan were 377.0 and 246.7%, respectively, compared to those for carboxymethyl-cellulose. The affinity and hydrolysis rate of pNPC by Cel5L-p35 were 1.7 and 3.3 times higher, respectively, than those by Cel5L-p50. Additions of each to a commercial enzyme set increased saccharification of pretreated rice straw powder by 17.5 and 21.0%, respectively. These results suggest CBM_3 is significantly contributing to thermostability, and to affinity and substrate specificity for small substrates, and that these two enzymes could be used as additives to enhance enzymatic saccharification.

• Biomedical Science Letters
• /
• v.25 no.3
• /
• pp.247-255
• /
• 2019

Curcuma longa L. (C.L), Curcuma aromatica Salisb. (C.A) and Zingiber officinale Rosc. (Z.O) of Zingiberaceae plants which are well known as effects of natural anti-oxidant, anti-cancer and anti-inflammatory. We examined that the Zingiberaceae plants are involved in development and modulation of orofacial pain in rats. Male, 7- to 8-week-old, Sprague-Dawley rats weighing 240~280 g were used in this study. Experiments were performed using acute pain model that was caused by the injection of 5% formalin into the right vibrissa pad. The number of scratching or rubbing to the injection site was recorded for 9 consecutive 5-minute intervals following injection of formalin. The experimental groups were acute orofacial inflammatory pain; control group (formalin, 5%), vehicle group (5% formalin after sodium carboxymethyl cellulose), single administration group, single mixed administration group, repeated administration group. The experiments were performed various concentrations of Zingiberaceae plants extract. Therefore, oral administration of C.L, C.A, and Z.O (p.o., concentrations of 12.5, 25 mg/mL) in orofacial inflammatory pain model substantially decrease the nociceptive behavior in a concentration dependent manner. And it tended to decrease at low concentration (12.5 mg/mL) of single mixed and repeated administration more than single administration. This result means that Zingiberaceae plants extract affects the modulation of acute orofacial inflammatory pain. Thus, Zingiberaceae plants extract may be a potential therapeutic treatment for orofacial inflammatory pain.