• Journal of Microbiology and Biotechnology
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• v.3 no.1
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• pp.31-38
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• 1993

A bacterial strain KY-l isolated from sewage was able to produce an extracellular agarase(agarose 4-glycanohydrolase. EC 3.2.1.81). The strain KY-1 was identified as Cytophaga fermentans subsp. agarovorans based on its morphological and physiological characteristics. The agarase was purified by ammonium sulfate precipitation followed by DEAE-Sephadex A-50. Bio-Gel P-100. and CM-Cellulose column chromatography. The molecular weight of the purified enzyme was 24 kDa by SDS-polyacrylamide gel electrophoresis. The optimum temperature and pH for the enzyme activity were 30^{circ}C and 7.5, respectively. The enzyme activity was significantly inhibited in the presence of 0.1 mM $HgCl_2$. whereas it was elevated 3 times by $MnSO_4$ at 1 mM concentration. The Km value and Vmax were 16.67 mg/ml and 3.77 unit/ml.min. The agarase gene was cloned into Escherichia coli MC1061 using the plasmid vector pBR322. A 1.4 Kb DNA fragment of PstI-digested chromosomal DNA of C. fermentans KY-l was inserted into the PstI site of pBR322. expressed in the E. coli. and up to 60% of the total enzyme was extracellularly secreted. Enzymatic properties of the extracellular agarases produced by both the transformant and the donor were very similar in terms of optimal pH and temperature.

• Journal of Environmental Science International
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• v.24 no.4
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• pp.541-547
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• 2015

Formation of disinfection by-products (DBPs) including trihalomethans (THMs) and haloacetic acids (HAAs) from chlorination of six different species (Chlorella vulgaris, Scenedesmus sp., Anabaena cylindrical, Microcystis aeruginosa, Asterionella formosa and Aulacoseira sp.) of algal extracellular organic matter (EOM). The EOM characteristics evaluation of six algal species reaching at the stationary phase in the growth curve showed most of its SUVA254 showed below 1 and this means hydrophilic organic matter is much higher than hydrophobic organic matter. Chloroform formation potential (CFFP), dichloroacetic acid formation potential (DCAAFP) and trichloroacetic acid formation potential (TCAAFP) were mainly composed of THMFP and HAAFP in the EOM of various algal species. In the case of THMFP/DOC and HAAFP/DOC values, EOM of blue-green algae has appeared highest and EOM of green algae and diatom in order. THMFP/DOC was higher than HAAFP/DOC in EOM of blue-green algae. In comparison of formation potential by unit DOC composed of HAAFP in algal species EOM, DCAAFP/DOC was 1.5 times to 7.5 time higher than TCAAFP/DOC in the EOM of blue-green algae, while DCAAFP/DOC was found to be relatively high compared to TCAAFP/DOC in the EOM of green algae and diatom.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.28 no.6
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• pp.421-433
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• 2002

In order to elucidate the pathogenesis of cleft lip and palate, first of all, it is necessary to understand the developmental mechanisms of growth factors and extracellular matrix proteins in the tissues of cleft lip and palate. We have performed immunohistochemical studies on human cleft lip and palate tissues to elucidate the pathogenetic implications of cleft lip and palate. 16 specimens from postnatal human cleft lip and palate subjects and 17 specimens from autopsy of prenatal human cleft lip and palate were fixed in 10% buffered formalin, embedded in paraffin. The sections were routinely stained by hematoxylin and eosin, also stained by PAS, and followed by immunohistochemical stainings using the antiseras of growth factors and extracellular matrix proteins such as PCNA, S-100, c-erb-B2, MMP-3, MMP-10, HSP-70, transglutaninase-C, E-cadherin, VEGF, vWF. Both the prenatal and postnatal specimens of cleft lip and palate showed dysplastic proliferation of the basal cell layer, increased infiltration of melanocytes into mucosal epithelium, sebaceous gland hyperplasia ingrowing into the muscular tissue of lip and palate, and fatty infiltration into the submucosal deep connective tissue. The strong reactions of MMP-3 and HSP-70 were detected in the tissues of cleft lip and palate, especially increased in degenerating muscle bundles, while the immunostainings of PCNA and c-erb-B2 were weakly positive in the tissues of cleft lip and palate. These data suggest that the retrogressive tissue degeneration around the cleft areas persistently exist during the prenatal and postnatal period after cleft formation, and the sebaceous gland hyperplasia and fatty infiltration with the intense expression of MMP-3 and HSP-70 is closely related to the muscular degeneration around the cleft area.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.11
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• pp.1229-1235
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• 2011

The extracellular matrix (ECM) is a key factor affecting cell growth and adhesion to the culture surface, and it is also important for maintaining the innate characteristics of cells. Here, we describe the effects of the ECM on cardiomyocyte (HL-1 cell line) growth, viability, phenotype, and contractile ability. Five different ECM materials were investigated to analyze their effects on the cell growth. The physical morphology of the ECM-coated surfaces was scanned with an atomic force microscope (AFM), and the attachment, growth, proliferation, viability, and phenotype of the cells were analyzed using fluorescence immunostaining and an inverted phase contrast microscope.

• Archives of Pharmacal Research
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• v.29 no.6
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• pp.508-513
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• 2006

The effect of acteoside, a phenylpropanoid glycoside isolated from Clerodendron trichotomum Thunberg, on histamine and arachidonic acid release was investigated in RBL 2H3 cells. Histamine was dose-dependently released from RBL 2H3 cells by melittin, arachidonic acid and thapsigargin. In extracellular $Ca^{2+}-free$ solution, basal secretion of histamins increased by two fold. The response of histamine release to melittin and thapsigargin in $Ca^{2+}-free$ solution was significantly decreased, whereas the response to arachidonic acid was significantly increased as compared with those in normal solution. Acteoside inhibited histamine release induced by melittin, arachidonic acid and thapsigargin in a dose-dependent manner in the presence or absence of extracellular $Ca^{2+}$. However, the inhibitory activity of acteoside was more potent in normal solution than that in $Ca^{2+}-free$ solution. These data suggest that inhibitory mechanism of acteoside on histamine release may be related to extracellular $Ca^{2+}$. On the other hand, acteoside significantly inhibited arachidonic acid release and prostaglandin $E_2$ production Induced by $0.5\;{\mu}M$ melittin. It is possible that acteoside may be developed as an anti-inflammatory agent.

• Molecules and Cells
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• v.38 no.2
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• pp.145-150
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• 2015

Continuous intra- and extracellular stresses induce disorder of $Ca^{2+}$ homeostasis and accumulation of unfolded protein in the endoplasmic reticulum (ER), which results in ER stress. Severe long-term ER stress triggers apoptosis signaling pathways, resulting in cell death. Neural epidermal growth factor-like like protein 2 (NELL2) has been reported to be important in protection of cells from cell death-inducing environments. In this study, we investigated the cytoprotective effect of NELL2 in the context of ER stress induced by thapsigargin, a strong ER stress inducer, in Cos7 cells. Overexpression of NELL2 prevented ER stress-mediated apoptosis by decreasing expression of ER stress-induced C/EBP homologous protein (CHOP) and increasing ER chaperones. In this context, expression of anti-apoptotic Bcl-xL was increased by NELL2, whereas NELL2 decreased expression of pro-apoptotic proteins, such as cleaved caspases 3 and 7. This anti-apoptotic effect of NELL2 is likely mediated by extracellular signal-regulated kinase (ERK) signaling, because its inhibitor, U0126, inhibited effects of NELL2 on the expression of anti- and pro-apoptotic proteins and on the protection from ER stress-induced cell death.

• Korean Journal of Microbiology
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• v.28 no.3
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• pp.199-203
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• 1990

To study distribution of bacterial flora and their biochemical characteristics in the Antarctic soilecosystem, these experiments were performed during the austral summer(Feb., 1989) on the King George Island, Antarctica. The numbers of heterotrophic bacterial colonies and extracellular enzyme actibities were estimated from the Antarctic terrestrial soils which were sampled from 17 different locations near Sejong station (Korea) and Teniente Jubany station (Argentina) on the King George Island. The numbers of heterotrophic bacterial colonies were extremely variable with sampling sites and incubation temperatures. Arithmetric average numbers were $2.5\times 10^{4}$, $2.7\times 10^{7}$ , $6.9\times 10^{5}$ CFU/$cm^{3}$ soil at the incubation temperature of $37^{\circ}C$, $25^{\circ}C$ and $4^{\circ}C$, respectively. The activities of extracellular $\alpha$-glucosidase, $\beta$-glucosidase and N-acetyl-$\beta$-glucosaminidase were shown as similar mean percentage in the colonies obtained at different temperatures. Mean value of protease activities, however, was remarkably higher (92%) in the colonies grown at $4^{\circ}C$,.

• Korean Journal of Microbiology
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• v.27 no.4
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• pp.348-356
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• 1989

An extracellular peroxidase found in culture broth of Pleurotus ostreatus was induced by syringic acid. This enzyme was fractionated by DEAE Sephadex A-50 ion exchange chromatography and gel filtration chromatogrphy on Sephadex G-150. The enzyme is a glycoprotein containing 35.7% carbohydrate. The results of SDS-linear polyacrylamide gradient gel electrophoresis and gel filtration indicate that the enzyme is a dimer consisted of identical subunits (Mr=72,400). The absorption spectrum of the enzyme indicates the presence of one mole of iron protoporphyrin IX per one mole of subunit. Isoelectric point of the enzyme is 4.26 and $K_m$ values for $H_2O_2$ is $7.2{\mu}M$. The enzyme showed its optimal activity at pH 3.5-4.0 and at $40^{\circ}C$. The Km values of this enzyme for ferulic acid and sinapic acid are 2.4 and 12.3 times higher than those of horseradish peroxidase, respectively.

• Biotechnology and Bioprocess Engineering:BBE
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• v.10 no.2
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• pp.109-114
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• 2005

Ion fluxes across the plasma membrane activated by 1 mM $Ce^{4+}$, cell apoptosis and taxol biosynthesis in suspension cultures of Taxus cusp/data were studied. The extracellular pH sharply decreased upon the addition of 1 mM $Ce^{4+}$, then increased gradually and exceeded the initial pH value over a time period of 12 h. The extracellular $Ca^{2+}$ concentration decreased within the first 3 h after the addition of $Ce^{4+}$, then gradually decreased to one third of initial value in control at about 72 h and remained unchanged afterwards. Experiments with an ion channel blocker and a $Ca^{2+}$-channel blocker indicated that the dynamic changes in extracellular pH and the $Ca^{2+}$ concentration resulted from the $Ce^{4+}$-induced activation of W uptake and $Ca^{2+}$ influx across the plasma membrane via ion channels. A pretreatment of the ion channel blocker initiated $Ce^{4+}$-treated cells to undergo necrosis, and the prior addition of the $Ca^{2+}$-channel blocker inhibited $Ce^{4+}$-induced taxol biosynthesis and apoptosis. It is thus inferred that W uptake is necessary for cells to survive a $Ce^{4+}$-caused acidic environment and is one of the mechanisms of $Ce^{4+}$-induced apoptosis. Furthermore, the $Ca^{2+}$ influx across the plasma membrane mediated both the $Ce^{4+}$-induced apoptosis and taxol biosynthesis.

• Journal of Soil and Groundwater Environment
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• v.19 no.2
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• pp.16-24
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• 2014

To test the potential effects of extracellular electron shuttles (EES) on the rate and extent of heavy metal release from contaminated soils during microbial iron reduction, we created anaerobic batch systems with anthraquinone-2,6-disulfonate (AQDS) as a surrogate of EES, and with contaminated soils as mixed iron (hydr)oxides and microbial sources. Two types of soils were tested: Zn-contaminated soil A and As/Pb-contaminated soil B. In soil A, the rate of iron reduction was fastest in the presence of AQDS and > 3500 mg/L of total Fe(II) was produced within 2 d. This suggests that indigenous microorganisms can utilize AQDS as EES to stimulate iron reduction. In the incubations with soil B, the rate and extent of iron reduction did not increase in the presence of AQDS likely because of the low pH (< 5.5). In addition, less than 2000 mg/L of total Fe(II) was produced in soil B within 52 d suggesting that iron reduction by subsurface microorganisms in soil B was not as effective as that in soil A. Relatively high amount of As (~500 mg/L) was released to the aqueous phase during microbial iron reduction in soil B. The release of As might be due to the reduction of As-associated iron (hydr)oxides and/or direct enzymatic reduction of As(V) to As(III) by As-reducing microorganisms. However, given that Pb in liquid phase was < 0.3 mg/L for the entire experiment, the microbial reduction As(V) to As(III) by As-reducing microorganisms has most likely occurred in this system. This study suggests that heavy metal release from contaminated soils can be strongly controlled by subsurface microorganisms, soil pH, presence of EES, and/or nature of heavy metals.