• The Korean Journal of Mycology
• /
• v.21 no.4
• /
• pp.301-309
• /
• 1993

An alkalophilic Cephalosporium sp. RYM-202 capable of producing cellulase components was isolated from soil. This organism grew best at an initial pH 9.0 and produced cellulase maximal at an initial pH 9.5-10.0. Three carboxymethyl cellulases(CMCases), P-I-I, P-I-II and P-II-I, were partially purified by DEAE-Sephadex A-50 ion exchange column followed by Sephadex G-150 gel filtration. The optimum pH values for activity were 7.5 for P-I-I, 8.0-9.5 for P-I-II and 7.5-10.0 for P-II-I. All CMCases were stable between pH 4.5 and 12.0. Temperature optima for activity ranged between 40 and $60^{\circ}C$ and more than 50% of the maximum activity was observed at $20^{\circ}C$ for both of P-I-I and P-II-I. The activity of CMCases was significantly stable in the presence of various laundry components, such as, surfactants, chelating agents and alkaline proteinases.

• Korean Journal of Soil Science and Fertilizer
• /
• v.36 no.4
• /
• pp.210-217
• /
• 2003

An alternative method to the empirical approach such as Langmuir and Freundlich model, surface complexation model using thermodynamic database is used to simulate adsorption behavior of cadmium for oxide minerals. Sorption of cadmium onto amorphous silica ($SiO_2$) and synthetic goethite (${\alpha}$-FeOOH) at various conditions of pH, initial cadmium loading, oxide concentration, and ionic strength, were investigated. For both oxide minerals, increasing cadmium concentration resulted in right shifting of the sorption curve of cadmium as the function of pH. The $pH_{50}$, where 50% of cadmium sorbed, of goethite (pH 5.25) was much smaller than that of the silica (pH 7.83). The sorption of cadmium onto both minerals were not affected by the background ion strength from $10^{-1}$ to $10^{-2}$ M of $KNO_3$. It indicated that the binding affinity of goethite surface for cadmium is much stronger than that of silica. The strong affinity of oxide mineral for cadmium can be explained by the existence of coordination or covalent bond between cadmium and surface of it.

• The Korea Journal of Herbology
• /
• v.26 no.1
• /
• pp.53-58
• /
• 2011

Objectives : The purpose of this study is to investigate effects of Scutellariae Radix Water Extract on hydrogen peroxide production in RAW 264.7 mouse macrophages. Methods : Scutellariae Radix produced from South Korea (SK) and Scutellariae Radix produced from China (SC) were extracted by hot water. Effects of SK and SC on hydrogen peroxide production in RAW 264.7 were measured by dihydrorhodamine 123 assay after 2, 4, 20, 24, 28, 44, and 48 h incubation at the concentrations of 10, 25, 50, and 100 ug/mL. Results : SK significantly increase hydrogen peroxide production in RAW 264.7 cells for 2, 4, 20, 24, 28, 44, and 48 h incubation at the concentrations of 10, 25, 50, and 100 ug/mL (P < 0.05). SC also significantly increase hydrogen peroxide production in RAW 264.7 cells for 4, 20, 24, 28, and 48 h incubation at the concentrations of 10, 25, 50, and 100 ug/mL (P < 0.05). For 2 h incubation, SC significantly increase hydrogen peroxide production in RAW 264.7 cells at the concentrations of 10, 25, and 100 ug/mL (P < 0.05). For 44 h incubation, SC significantly increase hydrogen peroxide production in RAW 264.7 cells at the concentrations of 10, 25, and 50 ug/mL (P < 0.05). Conclusions : These results suggest that Scutellariae Radix has the immune - enhancing property related with its increasement of hydrogen peroxide production in macrophages.

• Applied Chemistry for Engineering
• /
• v.10 no.1
• /
• pp.41-45
• /
• 1999

Simulated liquid waste containing 50 ppm cobalt ion was treated by precipitate flotation using the surfactant of sodium lauryl sulfate. The effects of initial cobalt ion concentration, pH, surfactant concentration, removal time, gas flow rate and foreign ions were estimated on removal efficiency. 35% $H_2O_2$ was added for pre-treatment stage before precipitate flotation. As the result of pre-treatment, optimum removal pH and the pH of treated water being discharged were lowed and optimum removal pH range was broadened. For the result of this experiment, 99.8% removal efficiency was obtained at the condition of 50ppm of initial cobalt ion concentration, pH 9.5, 70 mL/min of gas flow rate, and 30 min of removal time. Attraction between precipitate and surfactant was supposed to be influenced by solubility and chemical affinity among species in sloution as well as zeta potential. The influence of foreign ions such as, $NO_3{^-}$, ${SO_4}^{-2}$, $Na^+$, $Ca^{+2}$ on the removal efficiency was also observed. Removal efficiency by precipitate flotation containing 0.1 M of ${SO_4}^{-2}$ ion decreased to 90% due to the decrease of zeta potential and interruption of precipitation.

• Proceedings of the Korean Environmental Sciences Society Conference
• /
• 2006.11a
• /
• pp.153-155
• /
• 2006

메조포러스 탄소의 톨루엔 흡착은 peak가 사전실험을 거쳐 조사된 Reference에 도달함에 의해 파과되는 것을 확인하였다. pH와 촉매의 함량을 달리하여 제조한 메조포러스 탄소를 이용한 톨루엔의 흡착실험에서 MC50-6, MCl00-6, MC100-7, MC50-7의 순으로 파과됨을 나타내었다. 톨루엔 흡착에 효율적인 합성조건은 촉매보다는 pH에 따라 달리 제조된 메조포러스 카본이 우수함을 보여주었다.

• Microbiology and Biotechnology Letters
• /
• v.15 no.5
• /
• pp.306-311
• /
• 1987

After series of purification by means of ammonium sulfate fractionation, the 1st and 2nd DEAE-Cellulose, DEAE-Sephadex A-50, and Sephacryl S-200 superfine gel filtration, the activity of extracellular adenine deaminase from Streptomyces sp. J-350P increased 1764 fold and the yield was 0.3% of original activity. The enzyme was stable at the pH range 6.5 to 8.5 and at up to 5$0^{\circ}C$. The optimum pH and temperature of the enzyme were around 6.5 and 35$^{\circ}C$. The molecular weight ol the enzyme was estimated as 36, 000 by calibrated Sephacryl S-200 superfine column chromatography.

• Korean Journal of Food Science and Technology
• /
• v.16 no.4
• /
• pp.392-397
• /
• 1984

These experiments were conducted to investigate general enzymatic characteristics of two forms(glucoamylase I and glucoamylase II) of the purified glucoamylase produced by Rhizopus oryzae. Molecular weights of glucoamylase I and glucoamylase II estimated by Sephadex G-100gel filtration, were approximately 101,000 and 115,000, respectively, and those estimated by SDS-polyacrylamide gel electrophoresis being 120,000 and 127,000, respectively. Isoelectric points of the above enzyme were pH 7.25 and pH 7.75. The optimum temperature was $50^{\circ}C$ and the enzyme was stable below $45^{\circ}C$. Optimum pH of both glucoamylase I and glucoamylase II was about pH 5.0. The stable pH range of them were pH 3.5-8.0 and 4.5-8.0, respectively. Michaelis constants of glucoamylase I and glucoamylase II toward souluble starch were 4.545 mg/ml and 5.560 mg/ml, respectively. $Hg^{++}$, $Pb^{++}$, p-CMB and IAA were inhibitors of glucoamylase I and $Hg^{++}$, $Mn^{++}$, p-CMB and IAA were inhibitors of glucoamylase II.

• Journal of Korean society of Dental Hygiene
• /
• v.7 no.2
• /
• pp.167-176
• /
• 2007

Objectives: The purpose of this study was to investigate the dental caries activity of some commercial drinks. Methods : Acidity levels were recorded as pH values of original drinks and amount of 50%-sodium hydroxide(NaOH) required to neutralize by titration 50.00ml of the drink(It was called titratable acid). Acidity of the drinks with S. sobrinus was measured at an interval of one hour after incubating ($37^{\circ}C$) the test drinks and control solution which was composed 20.00ml of neutralized drinks as pH 7.0 with 0.2ml of a pooled suspension of S. sobrinus. Results : The drink with the highest pH value was the Cow's milk(pH $6.70{\pm}0.01$), and the most acidic was the Carbonated drink(pH $2.40{\pm}0.02$). The drink with the highest buffer effect was the Fruit juice($139.78{\pm}0.76$), and the lowest was the Glucose solution(control, $4.42{\pm}0.20$). The drinks with S. sobrinus during incubation at $37^{\circ}C$ for 24h were decreased to below critical pH 5.5. Spending times from pH 7.0 to pH 5.5~5.0 were Glucose solution(less than 1h). Carbonated drink(3h), Fruit juice(5h), Cow's milk(8h) and Mixed drink(21h). Conclusions: These results show that some commercial drinks with S. sorbrinus have the possibility of tooth decalcification. Thus, it is suggested that the people who have the low salivary secretion rate and the children who sleep without toothbrushing after drinking need the instruction for diet control and oral health education.

• Asian-Australasian Journal of Animal Sciences
• /
• v.17 no.7
• /
• pp.984-989
• /
• 2004

Three hundred and twelve female Tsaiya ducks from four lines (L1051, L1052, L1053 and L1054) were used in this study to investigate the changes in plasma calcium and inorganic phosphorus levels, blood pH, carbon dioxide partial pressure (pCO$_{2}$), bicarbonate ion concentration ($HCO_{3}^{-}$), and base excess (BE) during laying periods. The results indicated that plasma calcium and inorganic phosphorus concentration at 40 and 50 wks of age were higher (p<0.05) than those at other ages. Significant positive correlation coefficients were found between plasma calcium and inorganic phosphorus levels at each age tested from 20 to 50 wks. Ducks from L1053 showed lower (p<0.05) blood pH, BE and $HCO_{3}^{-}$ as compared with other lines. Ducks from L1054 had higher (p<0.05) blood pH, BE and $HCO_{3}^{-}$ than those of other lines showing that there were some differences on blood parameters among lines. Eggshell strength decreased with age up to 65 wks and remained constant thereafter. Egg weight increased gradually from 30 to 60 wks and decreased slightly after 70 wks of age. Plasma inorganic phosphorus level in 40 and 50 wks old birds was positively correlated with eggshell strength, while blood $HCO_{3}^{-}$ in 40 and 50 wks old birds was negatively correlated with eggshell strength.

• Journal of Sensor Science and Technology
• /
• v.5 no.4
• /
• pp.35-40
• /
• 1996

The polymeric membrane pH sensor based on HDBA(hexyldibenzylamine) or HDPA(hexyldiphenylamine) as hydrogen ion carrier was prepared and electrochemical characterization for the variation of a temperature and membrane thickness were studied on. The sensor based on HDPA was not responded selectively to hydrogen ion. The sensor based on HDBA was responded linearly to hydrogen ion in the range of pH 2 - pH 10, it showed the fast response time of 30 - 50sec. and Nernstian slope of 53.6mV/pH. The interfering effect on alkali and alkaline earth metal ions of pH sensor were lower than glass pH sensor. There was shown a good reproducibility and stability with the precision of 2 - 4mV (${\pm}0.1mV$).