• Journal of Microbiology and Biotechnology
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• v.26 no.7
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• pp.1234-1241
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• 2016

Methanol is a versatile compound that can be biologically synthesized from methane (CH₄) by methanotrophs using a low energy-consuming and environment-friendly process. Methylocella tundrae is a type II methanotroph that can utilize CH₄ as a carbon and energy source. Methanol is produced in the first step of the metabolic pathway of methanotrophs and is further oxidized into formaldehyde. Several parameters must be optimized to achieve high methanol production. In this study, we optimized the production conditions and process parameters for methanol production. The optimum incubation time, substrate, pH, agitation rate, temperature, phosphate buffer and sodium formate concentration, and cell concentration were determined to be 24 h, 50% CH₄, pH 7, 150 rpm, 30℃, 100 mM and 50 mM, and 18 mg/ml, respectively. The optimization of these parameters significantly improved methanol production from 0.66 to 5.18 mM. The use of alginate-encapsulated cells resulted in enhanced methanol production stability and reusability of cells after five cycles of reuse under batch culture conditions.

• Plant Resources
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• v.6 no.1
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• pp.81-88
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• 2003

Higenamine [1-(4-hydroxy-6, 7-dihydroxy-l, 2, 3, 4-tetrahydroisoquinoline) is a cardiotonic constituent of Aconiti tuber, one of the most widely prescribed oriental medicines. S-(-)higenamine was reported to have a stronger cardiotonic activity than R-(+)-higenamine and known as a central intermediate in the biosynthesis of various benzyl isoquionoline alkaloids in plants. The separation of higenamine enantiomers has been accomplished with capillary electrophoresis using cyclodextrins (CDs) as chiral selectors. Good resolution of this enantiomers was obtained using a 50 mM sodium phosphate buffer containing hydroxypropyl $\beta$-CDs using 27 cm fused silica capillary (50${\mu}{\textrm}{m}$ i.d., 20 cm to detector) at 25 $^{\circ}C$. With the electric field of 340 V/cm, the separation time of higenamine enantiomers was less than 6 min. Under this optimum conditions, the relative standard deviations of migration time and peak area were less than 1.6% and 3.2%. A 512-channel diode array detector was confirmed for the higenamine. The detection limits (S/N = 3) of these enantiomers are $1.5mutextrm{m}$/mL. We confirmed the chiral form of higenamine in medicinal plants.

• Korean Journal of Medicinal Crop Science
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• v.24 no.1
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• pp.27-30
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• 2016

Background : This text was conducted to evaluate the distribution, shape characteristics and habitat condition of Crypsinus hastatus in Buyeo Korea. Methods and Results : In Buyeo, Crypsinus hastatus was distributed at an altitude of 31.2 m, a slope of 82.5% and a distance from river water of 27.2 m. The leaf blade was oblong, 2.7 cm long, 1.2 cm wide with a petiole length of 2.3 cm. The total population comprised 2,100 individuals, with the highest proportion being individuals with a leaf blade of length 0.5 - 1 cm. The temperature and light intensity of the growth point were lower, but the humidity higher, than that of growth around. The chemical properties of the soil were as follows: pH 4.42, organic matter 77.99 g/kg, electrical conductivity 0.50 dS/m, nitrate nitrogen 20.50 mg/kg and available phosphate 165.7 mg/kg. Exchangeable cation content of potassium, magnesium, sodium and calcium was 0.35, 0.70, 0.09 and $2.04cmol^+/kg$, respectively. Conclusions : In Buyeo, Crypsinus hastatus was distributed in $5.3m^2$ area of Nakhwaam, Naeseongri and Jeongamri. However, the population of the medicinal resources seemed to decrease owing to the poor environmental conditions of the habitat.

• Korean Journal of Microbiology
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• v.15 no.3
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• pp.123-130
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• 1977

In previous paper, it was reported that antibiotic substance such as tetracycline and streptomycin were produced by S'. albus subsp. and S'. globosus. And increase of mycelial growth of two strains, antibiotic production, and changes of pH range are extended to approximately 110-130 hrs in fermenting medium, there-after they decreased with culture period exception of pH range. Two Streptomyces spp. required commonly 4-5% starch as carbon sources and 1.5-2.0% soybean meal as nitrogen sources. However, 0.005-0.01M potassium phosphate dibasic, calcium carbonate (6mg/ml in S.albus subsp. and 2mg/ml in S. globosus), 0.01-0.03M, magnesium sulgate and 0.01M ferric chloride showed as optimal concentration for the growth of 2 strains. Mineral compoments such as zinc, manganese, cobalt, sodium and copper at the level of 10/sup -4/ -10/sup -6/M were observed. Especially, zinc ion showed toxicity to the growth of 2 strains at 0.005M. In relation with pH, there is a little difference in mycelial growth with cultural initial pH.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.16 no.2
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• pp.190-199
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• 2009

Purpose: This study was conducted to identify the factors contributing to sleep disorders in patients on hemodialysis. Methods: A descriptive correlational study design was used. The participants were 135 patients on hemodialysis in hemodialysis clinics. Data were collected from March to May 2007 using structured questionnaires and hematologic sample. Stepwise multiple regression was used to identify factors influencing sleep disorders among the demographic-clinical factors, depression and fatigue. Results: About 69% of the patients had a sleep disorders. There were significant differences in sleep disorders according to marital status, caregiver, religion, economic level, insurance, erythropoietin, somnifacient, and antihypertensive agents. But there were no differences according to age, gender, dialysis period, or antidepressants. Their sleep disorders had significant correlations with depression, and fatigue, and a significant negative correlation with Protein, Albumin, Phosphate and BUN. But there were no correlations with hematocrit, hemoglobin, creatinine, sodium, potassium, or calcium. Depression and fatigue were factors influencing sleep disorders. They accounted for 43.8% of the variance in sleep disorders in these patients. Conclusion: Findings provide an understanding of sleep disorders and the factors that are an influence in patients on hemodialysis. To promote sleep in these patients, nursing interventions to manage depression and fatigue are needed.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.567-570
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• 2000

The condition of immobilization of the partially purified levan fructotransferase and the properties of the immobilized enzyme was investigated. Levan fructotransferase was immobilized on ${\kappa}\;-carrageenan$ beads by entrapment method. The optimal ${\kappa}\;-carrageenan$ concentration was obtained 2%(w/v) (or the matrix. At that time, immobilized enzymes(0.81 units) have relative low activity compare with soluble enzyme(7.7 units). To immobilized and soluble enzyme, optimal activity temperature and pH were measured $55^{\circ}C$, 6.0 in sodium phosphate buffer 20mM solution. If crosslinking agent was added, proper concentration was 0.5%(v/v). At $37^{\circ}C$, immobilized and soluble enzyme converted levan to oligofructose and DFA IV, and the conversion ratio was 32% and 61% at 60 hr.

• KSBB Journal
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• v.26 no.6
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• pp.529-532
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• 2011

Whey based medium was optimized for the production of viable Lactobacillus crispatus KLB 46 isolated from the vagina of Korean women. Among the various nitrogen sources such as yeast extract, beef extract, and proteose peptone no. 3 supplemented to whey, beef extract showed the highest viable cell production. The addition of Tween 80 to the whey based medium increased viable cell concentration. As beef extract supplementation is not economically attractive, corn steep liquor was added as a supplementary nitrogen sources. When corn steep liquor was supplied with beef extract with the ratio 5 : 1, the viable cell count was $3.11{\times}10^9$ CFU/mL. Also, the addition of mineral salts containing sodium acetate (5 g/L), potassium phosphate dibasic (2 g/L), magnesium sulfate (0.1 g/L) and manganese sulfate (0.05 g/L) to the whey medium increased viable cell count further ($5.00{\times}10^9$ CFU/mL).

• Bulletin of the Korean Chemical Society
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• v.35 no.7
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• pp.2109-2113
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• 2014

Solvent extraction of Fe(III) from chloride solution by using a mixture of D2EHPA (Di-(2-ethylhexyl)-phosphoric acid) and TBP (Tri-butyl phosphate) and the reductive stripping of Fe(III) from the loaded organic were investigated. Quantitative extraction of Fe(III) from the solution (Fe concentration = 90 g/L) was accomplished in two cross-current extraction stages by using the mixture of D2EHPA and TBP. In order to facilitate the stripping efficiency, a reductive stripping method was employed by using $H_2SO_3$ or $Na_2SO_3$ as a reducing agent. The addition of $H_2SO_4$ into reducing agents led to improvement in the stripping efficiency while high concentration acid would suppress it. Both of the mixtures of $H_2SO_4+H_2SO_3$ and $H_2SO_4+Na_2SO_3$ showed good efficiency for the stripping of Fe(III), while the latter was recommended as the stripping solution based on the economics and experimental condition.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2002.11b
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• pp.53-53
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• 2002

Shoot tips of in vitro propagated plantlets were cryopreserved using encapsulation/dehydration procedures. Shoot tips were excised under filter sterilized antioxidants solution (0.2M phosphate buffer, pH 5.7 supplemented with 5g/1 ascorbic acid and 15g/1 sodium borate). They were drawn up into a sterile 10 $\textrm{cm}^3$disposable pipette and were dropped into the culture medium with 2.5w/v Na-alginate, then into 100mM CaCl$_2$.2$H_2O$. Encapsulated shoot tips were transferred into 10㎤ of liquid culture medium with a range of sucrose concentrations (0.25-1.0M) and were incubated in dark for 24 hours in 18C at 40rpm. Beads were then dehydrated in silica gel for different time intervals (1-24 hours). Then they were freeze dried either rapidly (plunge directly into liquid N2 or in two stages (samples were kept at 20C for 10 minutes, then reduced to 35C at 1C per minute. Then, plunge into liquid $N_2$). The influence of sucrose and silica gel pre-treatment on pre- and post-freeze shoot growth was examined.(중략)

• Archives of Pharmacal Research
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• v.29 no.12
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• pp.1096-1101
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• 2006

Armeniacae Semen not only contains amygdalin, but emulsin also, which is an enzyme that hydrolyzes amygdalin. The extraction yield of amygdalin from Armeniacae Semen was low, due to the presence of emulsin, when extracted with water. When Schizandrae Fructus solution was used as the extractant; however, amygdalin was almost completely extracted, regardless of the cutting size, due to the absence of the influence of emulsin. In addition, when the crude powder or small piece forms were used with Schizandrae Fructus solution, on epimerization of the D-amygdalin into neoamygdalin occurred. D-amygdalin and its conversion product, neoamygdalin, were quantitatively analyzed by reverse-phase, high-performance liquid chromatography (HPLC), with an optimized eluent of 10 mM sodium phosphate buffer (pH 2.3), containing 11.5% acetonitrile. The concentration and detector response were linearly correlated over the range 0.05 to 2 mM. The detection limits for both D-amygdalin and neoamygdalin were approximately $5\;{\mu}M$ for the amount injected.