• Proceedings of the Materials Research Society of Korea Conference
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• 2011.10a
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• pp.29.1-29.1
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• 2011

The selective catalytic reduction (SCR) of $MnO_x$ with $NH_3$ is an effective method for the removal of $MnO_x$ from stationary system. The typical catalyst for this method is $V_2O_5-WO_3(MoO_3)/TiO_2$, caused by the high activity and stability. However, This catalyst is active within $300{\sim}400^{\circ}C$ and occurs the pore plugging from the deposition of ammonium sulfate salts on the catalysts surface. It needs to locate the SCR unit after the desulfurizer and electrostatic precipitator without reheating of the flue gas as well as deposition of dust on the catalyst. The manganese oxides supported on titania catalysts have attracted interest because of its high SCR activity at low temperature. The catalytic activity of $MnO_x/TiO_2$ SCR catalyst with different manganese precursors have investigated for low-temperature SCR in terms of structural, morphological, and physico-chemical analyses. The $MnO_x/TiO_2$ were prepared from three different precursors such as manganese nitrate, manganese acetate (II), and manganese acetate (III) by the sol-gel method and then it calcinated at $500^{\circ}C$ for 2 hr. The structural analysis was carried out to identify the phase transition and the change intensity of catalytic activity by various manganese precursors was analyzed by FT-IR and Raman spectroscopy. These different precursors also led to various surface Mn concentrations indicated by SEM. The Mn acetate (III) tends to be more suppressive the crystalline phase (rutile), and it has not only smaller particle size, but also better distributed than the others. It was confirmed that the catalytic activity of MA (III)-$MnO_x/TiO_2$ was the highest among them.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.7
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• pp.560-570
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• 2017

Recently, well-known SAR imaging algorithms have been developed to form the focused SAR images for stationary targets. In general, the conventional methods exploit the range variation only defined by the motion of radar platform and SAR geometry. However, for SAR imaging of ground moving targets, the motion of the targets induces an additional range shift, yielding the blurred SAR images. To overcome the problem, in this paper we propose an effective motion compensation algorithm operated under a multi-channel SAR, named along-track interferometry(ATI) and phase unwrapping to directly estimate the motion parameters of the targets. In simulations, 50 Monte-Carlo simulation results show the effectiveness of the algorithm in the presence of noise.

• Journal of Mushroom
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• v.14 no.4
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• pp.244-248
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• 2016

In order to isolate thermophilic bacteria with high activity of CMCase and xylanase, spent mushroom substrates was collected from an oyster mushroom cultivation farm in Jinju, Gyeongnam, Korea. Among the isolates, one strain designated as YJ09 was selected by agar diffusion method. The isolate YJ09 was identified as a member of Bacillus licheniformis based on biochemical characteristics using Bacillus ID kit and MicroLog system. Comparative 16S rDNA sequence analysis showed that isolate YJ09 formed a distinct phylogenetic tree within the genus Bacillus and was most closely related to Bacillus licheniformis with sequence similarity of 98.9%. Based on its physiological properties, biochemical characteristics and phylogenetic distinctiveness, the isolate YJ09 was classified as Bacillus licheniformis. The CMCase and xylanase activity of B. licheniformis YJ09 was slightly increased corresponding to the bacterial population from exponential phase to stationary phase in the growth curve of B. licheniformis YJ09.

• Microbiology and Biotechnology Letters
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• v.17 no.5
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• pp.510-518
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• 1989

Most of orange peels are disposed from orange juice manufacturing process. Thus, our purpose is to utilize these orange peels as fermentation substrate. We have investigated culture conditions and factors influencing citric acid production by an isolated strain, Asp. niger. Citric acid production was much higher in semisolid culture than in submerged culture and the particle size of ground orange peels was favored at 20 mesh in semisolid culture. The optimal pH and temperature were 4.5-5.0 and 3$0^{\circ}C$ respectively and the temperature cycling at 35$^{\circ}C$ for 20 hrs durig exponential phase, 1$0^{\circ}C$ for 4 hrs and 3$0^{\circ}C$ during stationary phase showed higher citric acid production than did at fixed temperature, 3$0^{\circ}C$. The addition of NH$_4$NO$_3$0.2%, MgSO$_4$7$H_2O$ 0.1%, methanol 2.5%, ethanol 1.5%, to culture medium promoted citric acid production but the addition of trace metal ions as nutrients had not effect on the acid production in orange peel medium. Under the optimal culture conditions, maximum yield of citric acid was 80.4% in solid medium. Almost of all original components of citrus peel was consumed by Asp. niger during fermentation.

• Journal of Microbiology and Biotechnology
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• v.19 no.12
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• pp.1635-1643
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• 2009

The aim of this study was to provide new insight into the mechanism whereby the housekeeping enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH) locates to cell walls of Lactobacillus plantarum 299v. After purification, cytosolic and cell wall GAPDH (cw-GAPDH) forms were characterized and shown to be identical homotetrameric active enzymes. GAPDH concentration on cell walls was growth-time dependent. Free GAPDH was not observed on the culture supernatant at any time during growth, and provoked cell lysis was not concomitant with any reassociation of GAPDH onto the cell surface. Hence, with the possibility of cw-GAPDH resulting from autolysis being unlikely, entrapment of intracellular GAPDH on the cell wall after a passive efflux through altered plasma membrane was investigated. Flow cytometry was used to assess L. plantarum 299v membrane permeabilization after labeling with propidium iodide (PI). By combining PI uptake and cw-GAPDH activity measurements, we demonstrate here that the increase in cw-GAPDH concentration from the early exponential phase to the late stationary phase is closely related to an increase in plasma membrane permeability during growth. Moreover, we observed that increases in both plasma membrane permeability and cw-GAPDH activity were delayed when glucose was added during L. plantarum 299v growth. Using a double labeling of L. plantarum 299v cells with anti-GAPDH antibodies and propidium iodide, we established unambiguously that cells with impaired membrane manifest five times more cw-GAPDH than unaltered cells. Our results show that plasma membrane permeability appears to be closely related to the efflux of GAPDH on the bacterial cell surface, offering new insight into the understanding of the cell wall location of this enzyme.

• Microbiology and Biotechnology Letters
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• v.17 no.2
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• pp.94-99
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• 1989

Seven gtrains of Lactobacillus produce bacteriocin being active for Lacidophilus. All strains producing bacteriocin were found to be L. acidophilus except with one strain of L. gasseri. The maximum activity of bacteriocin produced by Lactobacillus strains was obtained at a middle or late stage of the log phase, or a early stage of the stationary phase. After the maximum was reached, however, the activity was rapidly decreased. The bacteriocins were inactivated easily by the treatment with proteolytic enzymes but not with nucleolytic enzymes, suggesting that the bacteriocin was proteinaceous. The bacteriocins were different from the other previously reported lactobacillus bacteriocin in their flexibility to the treatment at 10$0^{\circ}C$. Bacteriocins of L. acidophilus ATCC 9857 and 4357 decreased in activity by the treatment with diethylether, presumably the bacteriocin contained of a lipid component. It sums likely that L. acidophilus A4 bacteriocin adsorb to a regularly arrayed layer of the cell wall.

• Journal of Microbiology and Biotechnology
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• v.24 no.12
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• pp.1609-1621
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• 2014

The plant pathogen Burkholderia gladioli, which has a broad host range that includes rice and onion, causes bacterial panicle blight and sheath rot. Based on the complete genome sequence of B. gladioli BSR3 isolated from infected rice sheaths, the genome of B. gladioli BSR3 contains the luxI/luxR family of genes. Members of this family encode N-acyl-homoserine lactone (AHL) quorum sensing (QS) signal synthase and the LuxR-family AHL signal receptor, which are similar to B. glumae BGR1. In B. glumae, QS has been shown to play pivotal roles in many bacterial behaviors. In this study, we compared the QS-dependent gene expression between B. gladioli BSR3 and a QS-defective B. gladioli BSR3 mutant in two different culture states (10 and 24 h after incubation, corresponding to an exponential phase and a stationary phase) using RNA sequencing (RNA-seq). RNA-seq analyses including gene ontology and pathway enrichment revealed that the B. gladioli BSR3 QS system regulates genes related to motility, toxin production, and oxalogenesis, which were previously reported in B. glumae. Moreover, the uncharacterized polyketide biosynthesis is activated by QS, which was not detected in B. glumae. Thus, we observed not only common QS-dependent genes between B. glumae BGR1 and B. gladioli BSR3, but also unique QS-dependent genes in B. gladioli BSR3.

• Korean Chemical Engineering Research
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• v.48 no.4
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• pp.515-518
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• 2010

D,L-tryptophans were separated by using $Chirobiotic^{(R)}$ T HPLC column. Mobile phases were the mixture of methanol and water(70:30, 80:20, 90:10, v/v). Experimental temperatures were adjusted as 25, 40 and $55^{\circ}C$ in order to compare retention times. Difference in D,L-tryptophan retention times was studied in terms of the interaction between stationary phase and tryptophans. Selectivity, resolution and efficiency of column were utilized to find an optimum separation condition. Retention times were shortened by increasing the amount of methanol in mobile phase and the temperature of column. The best selectivity and resolution was obtained with the temperature($25^{\circ}C$) and the ratio of mobilephase(70/30 v/v%).

• KSBB Journal
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• v.11 no.4
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• pp.438-444
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• 1996

Using recombinant Vaccinia virus(vSC8) that express ${\beta}$-galactosidase, a model heterologous protein, conditions for virus and protein production were investigated in tissue culture flask. As host animal cells HeLa and HeLa S3 were used. It was demonstrated that cells infected during the exponential growth phase gave higher protein yield than those infected during the stationary growth phase and calf serum concentration after virus infection did not significantly alter protein yield. Pretreatment of cell layer with hypotonic solution enhanced the virus infectivity. Optimum cell growth and recombinant protein production was achieved at $37^{\circ}C$. But, during 2 hours of virus infection period incubation temperature must be lowered to 20∼$30^{\circ}C$ for maximum recombinant protein yield. To enhance virus replication, the effects of adrenal glucocorticoid hormone (Dexamethasone) and silkworm hemolymph were evaluated. Only dexamethasone increased about 20% of ${\beta}$-galactosidase yield in HeLa S3 cells when added with 10-7∼10-5M concentration 24 hours before infection.

• Journal of Microbiology and Biotechnology
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• v.17 no.9
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• pp.1452-1459
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• 2007

The Dps protein, which is overexpressed in harsh environments, is known to playa critical role in the protection of DNA against oxidative stresses. In this study, the roles of Fur in the expression of the dps gene in Salmonella and the protection mechanisms against oxidative stress in Salmonella cells preexposed to iron-stress were investigated. Two putative Fur boxes were predicted within the promoter region of the S. typhimurium dps gene. The profile of dps expression performed by the LacZ reporter assay revealed growth-phase dependency regardless of iron-status under the culture conditions. The fur mutant, $_X4659$, evidenced a reduced level of ${\beta}$-galactosidase as compared to the wild-type strain. The results observed after the measurement of the Dps protein in various Salmonella regulatory mutants were consistent with the results acquired in the reporter assay. This evidence suggested that Fur performs a function as a subsidiary regulator in the expression of dps. The survival ability of Salmonella strains after exposure to oxidative stress demonstrated that the Dps protein performs a pivotal function in the survival of stationary-phase S. typhimurium against oxidative stress. Salmonella cells grown in iron-restricted condition required Dps for full protection against oxidative stress. The CK24 (${\Delta}dps$) cells grown in iron-replete condition survived at a rate similar to that observed in the wild-type strain, thereby suggesting the induction of an unknown protection mechanism(s) other than Dps in this condition.