• Microbiology and Biotechnology Letters
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• v.17 no.5
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• pp.436-439
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• 1989

The chromosomal DNA fragments of thermophilic alkalophilic Bacillus sp, K-17, a potent xylanhydrolyzing bacterium, were ligated to a vector plasmid pBR322 and transformed into Escherichia coli HB101. The plasmid pAX278, isolated from a transformant forming yellow color on the LB agar plate containing 1 mM p-nitrophenyl- $\beta$-xylopyranoside, was found to enable the transformants to produce p-xylosidase. The 5.0 kilobase insert of pAX278 had single sites for EcoRI, PstI, XbaI, and PvuII, and 2 sites for BglII. Biotinylated pAX218 was hybridized to 0.9 kb as well as 5.0 kb fragment from Bacillus sp. K-17 DNA on nitrocellulose filter. pGX718 was constructed by inserting the 5.0 kb HindIII fragment of pGX278 at the HindIII site of pGR71, E. coli and B. subtilis shuttle vector. The enzymatic properties of $\beta$-xylosidase from E. coli HB101 carrying recombinant plasmid were the same those of $\beta$-xylosidase from Bacillus sp. K-17.

• Korean Chemical Engineering Research
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• v.46 no.3
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• pp.545-549
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• 2008

The surface characteristics of calcined ${\gamma}-Al_2O_3$ particles as well as ${\gamma}-AlO$(OH) sol particles were controlled by aging in the boehmite sol preparation. As a result of the study, the IEPs of ${\gamma}-AlO$(OH) particles were decreased from pH 9.25 to pH 8.70 and those of the calcined ${\gamma}-Al_2O_3$ particles were decreased from pH 9.90 to pH 8.86 by the increase of the aging times. As a result of the acidic and basic characterization of the calcined ${\gamma}-Al_2O_3$ particles by the aging, the amount of acid sites was decreased from 0.1367 mmol/g to 0.0783 mmol/g by the increase of the aging times and Hammett acidity, $H_o$ was showed the acidic strength of 4.8 or above. On the other hand, the amount of basic sites was decreased from 0.4399 mmol/g to 0.3074 mmol/g by the increase of the aging times. Based on these results, we proposed the fact that the aging step in the sol-gel process was an important step to control the surface characterization of ${\gamma}-Al_2O_3$ particles including acidity and basicity.

• Journal of Korean Society for Atmospheric Environment
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• v.5 no.2
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• pp.42-54
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• 1989

This study was carried out to investigate the phenomena of acid precipitation. The pH value, electro conductivity and major anions (sulfate, nitrate and chloride) were measured by automatic acid rain monitor and ion chromatography at 5 points in Seoul area from Jan. to Dec. 1988. 1. The acidity of rainfall was in order winter (4.31) spring (4.77) fall (4.94) summer (5.31). Rainfall with a pH of less than 5.6 was appeared 83.2 percent. 2. The range of the highest appearence frequency rate both at Hannam-dong and Songsu-dong was from pH 4.6 to 5.0 and appeared 30.7 percent and 38.3 percent respectively, Bang-i-dong was 36.3 percent in the ranged from pH 4.1 to 4.5 and Guro and Ssangmun-dong were 26 percent and 30.3 percent in the ranged from pH 5.1 to 5.5 respectively. 3. The sulfate and nitrate ion concentration in earlier rainwater ranged from 0.1 ppm to 50.2 ppm and from 0.01 ppm to 15.8 respectively. The earlier rainwaters were generally more acidic than the after rainwaters. 4. The order of the major anion concentration in rainwater was $SO_4^{2-} > Cl^- > NO_3^-$ and the acidity of it was more effective by sulfate ion than others. The correlation between pH value and anions concentration was shown positive correlationship at Guro-dong and Bang-i-dong and negative correlation at Hannam-dong but not at the other sites.

• The Korean Journal of Mycology
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• v.24 no.1 s.76
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• pp.56-66
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• 1996

Ecological variations of Arbuscular mycorrhizal (AM) fungi were determined from the soils collected from different sites of the polluted and unpolluted areas related to the soil pollutions. Average 24.5 spores $(per\;20g)^{-1}$ soil of AM fungal spore were counted from the 32 sites of soils collected from On-san (polluted), whereas average 4.1 spores $(per\;20g)^{-1}$ soil from the 18 sites of those from Mt. Kwanak (polluted); Average 23.6 spores $(per\;20g)^{-1}$ soil of AM fungal spore were also counted from the 30 sites of soils collected from Chung-mu (unpolluted), whereas average 15.8 spores $(per\;20g)^{-1}$ soil from the 14 sites of those from Mt. Chungwang (unpolluted).The spores of AM fungi were the species of Glomus, Gigaspora, Acaulospora and Scutellospora. Among the above four genera, the species of Glomus were observed to be more abundant than the other genera in the soils collected from On-san, Chung-mu and Mt. Chungwang whereas the species of Gigaspora in those from Mt. Kwan-ak. The parameters of soils measured showed some variations between the polluted and unpolluted areas; 12.9 to 16.4% in the soil moisture, 5.6 to 8.3% in the organic matter and 4.3 to 5.7 at soil pH (polluted to unpolluted areas, respectively). The soils collected, thereby, appeared to be more strongly acidic and also lower in the contents of soil moisture or organic matter at the polluted area than unpolluted area. Based on the ecological criteria, the species richness or species diversity had significant differences (p<0.05) between polluted and unpolluted area. The spore density of genus Glomus or Gigaspora was significantly different (p<0.05) among the soils of three different plant vegetations (conifer plants, broad leaf plants, and grass plants). Also, there were significant differences (p<0.05) in the species evenness or species diversity among the soils referring to three different plant vegetations. There was a direct relationship $(r^2=0.38)$ between soil moisture and organic matter measured from 94 soil samples. Since there was a direct relationship $(r^2=0.22)$ between organic matter and total spores, it seems to be likely to presume that mycorrhizal spores can be increased in proportion to enhanced organic matters in soils. The species richness or species diversity was inclined to increase in proportion to enhanced soil pH and total spores in soils.

• Journal of the Korean Institute of Landscape Architecture
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• v.31 no.2
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• pp.83-93
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• 2003

This study was conducted for an understanding of a threatened plant species,“Penthorum chinense”, which is a vegetation structure and environmental characteristic in the southern part of Ibaraki, Japan. We selected distribution and contiguity area where P. chinense is not distributed and we set up 69 sites by the quardrat method. The surveyed general characters in each site include mean-height, mean-coverage, moisture condition water depth coverage and depth of litter layer. We calculated the degree of succession by the survey data and grasped the main distribution area, vegetation structure, growth environment of P. chinense by TWINSPAN classification and DCA ordination. The results of this study are as follows. First, P. chinense habitat was categorized into the riverside and abandoned paddy fields. The riverside was influenced by natural disturbance caused by flooding and drought. These conditions led to a poor P. chinense growth. The abandoned paddy fields as the artificial disturbance area have high potential value, because the area can preserve P. chinense growth space by succession control and water management. second, we executed TWINSPAN analysis based on vegetation coverage data of survey sites. The vegetation types were classified into the three categories: annual plant flora(P. chinense dominates in wet state), perennial plant flora(Solidago altissima dominates in dry state), and perennial plant flora(Phragmites communis dominates in wet state). Third, the data was ordinated by DCA. The sample sequences along the first and second DCA axes effectively reflected moisture condition, number of species, mean height, coverage of litter layer and degree of succession. Especially, P. chinense flora has the high correlation with moisture condition and number of species.

• The Plant Pathology Journal
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• v.32 no.1
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• pp.33-46
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• 2016

In this study, the full-length nucleotide sequences of four Iranian PVY isolates belonging to $PVY^N$ strain were determined. The genome of Iranian PVY isolates were 9,703-9,707 nucleotides long encoding all potyviral cistrons including P1, HC-Pro, P3, 6K1, CI, 6K2, VPg, NIa-Pro, NIb and CP with coding regions of 825, 1,395, 1,095, 156, 1,902, 156, 564, 732, 1,557 and 801 nucleotides in length, respectively. The length of pipo, embedded in the P3 cistron, was 231 nucleotides. Phylogenetic analysis showed that the Iranian isolates clustered with European recombinant NTN isolates in the N lineage. Recombination analysis demonstrated that Iranian $PVY^N$ isolates had a typical European $PVY^{NTN}$ genome having three recombinant junctions while $PVY^N$ and $PVY^O$ were identified as the parents. We used dN/dS methods to detect candidate amino acid positions for positive selection in viral proteins. The mean ${\omega}$ ratio differed among different genes. Using model M0, ${\omega}$ values were 0.267 (P1), 0.085 (HC-Pro), 0.153 (P3), 0.050 (CI), 0.078 (VPg), 0.087 (NIa-pro), 0.079 (NIb) and 0.165 (CP). The analysis showed different sites within P1, P3 and CP were under positive selection pressure, however, the sites varied among PVY populations. To the best of our knowledge, our analysis provides the first demonstration of population structure of $PVY^N$ strain in mid-Eurasia Iran using complete genome sequences and highlights the importance of recombination and selection pressure in the evolution of PVY.

• Journal of Microbiology and Biotechnology
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• v.27 no.9
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• pp.1586-1592
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• 2017

Some promoters were isolated and characterized from the genome of Leuconostoc mesenteroides SY2, an isolate from kimchi, a Korean traditional fermented vegetable. Chromosomal DNA of L. mesenteroides SY2 was digested with Sau3AI and ligated with BamHI-cut pBV5030, a promoter screening vector containing a promoterless cat-86. Among E. coli transformants (TFs) resistant against Cm (chloramphenicol), 17 were able to grow in the presence of $1,000{\mu}g/ml$ Cm and their inserts were sequenced. Transcription start sites were examined for three putative promoters (P04C, P25C, and P33C) by primer extension. Four putative promoters were inserted upstream of a promoterless ${\alpha}$-amylase reporter gene in $pJY15{\alpha}$. ${\alpha}$-Amylase activities of E. coli TFs containing $pJY15{\alpha}$ (control, no promoter), $pJY03{\alpha}$ ($pJY15{\alpha}$ with P03C), $pJY04{\alpha}$ (with P04C), $pJY25{\alpha}$ (with P25C), and $pJY33{\alpha}$ (with P33C) were 66.9, 78.7, 122.1, 70.8, and 99.3 U, respectively. Cells harboring $pJY04{\alpha}$ showed 1.8 times higher activity than the control. Some promoters characterized in this study might be useful for construction of food-grade expression vectors for Leuconostoc sp. and related lactic acid bacteria.

• Archives of Pharmacal Research
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• v.25 no.2
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• pp.208-213
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• 2002

The human polyomavirus JC virus is the etiologic agent of progressive multifocal leukoencephalopathy (PML). As the JC virus early promoter directs cell-specific expression of the viral replication factor large T antigen, transcriptional regulation constitutes a major mechanism of glial tropism in PML. It has been demonstrated that SV4O or JC virus large T antigen interacts with p53 protein and regulates many viral and cellular genes. In this study we founts that p53 represses the JC virus early promoter in both glial and nonglial cells To identify the cis-regulatory elements responsible for p53-mediated repression, deletional and site-directed mutational analyses were performed . Deletion of the enhancer region diminished p53-mediated transcriptional repression. However, point mutations of several transcription factor binding sites in the basal promoter region did not produce any significant changes. In support of this observation, when the enhancer was fused to a heterologous promoter, p53 red reduced the promoter activity about three fold. These results indicate that the enhancer region is important for tole repression of JC virus transcription by p53. Furthermore, coexpression of JC virus T antigen with a p53 protein abolished p53-mediated repression of the JC virus early promoter in non-glial cells, but not in glial cells. This finding suggests that T antigen interacts with p53 and regulates JC virus transcription in a cell-specific manner.

• Journal of Life Science
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• v.10 no.2
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• pp.210-217
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• 2000

A kinetic profile of the catalytic domain of stromelysin-1 (SCD) using the fluorescent peptide substrate has been determined by the stopped-flow technique. The pH profile has a pH optimum of about 5.5 with an extended shoulder above pH 7. Three pKa values, 5.0, 5.7, and 9.8 are found for the free enzyme state and two pH independent Kcat/Km values of 4.1$\times$104 M-1 s-1 and 1.4$\times$104 M-1 s-1 at low and high pH, respectively. The profile is quite different in shape with other MMP family which has been reported, having broad pH optimum with two pKa values. The substrate specificity of SCD towards fluorescent heptapeptide substrates has been also examined by thin layer chromatography. The cleavage sites of the substrates have been identified using reverse-phase HPLC method.SCD cleaves Dns-PLA↓L↓WAR and Dns-PLA↓L↓FAR at two positions. However, the Dns-PLA↓LRAR, Dns-PLE↓LFAR, adn Dns-PLSar↓LFAR are cleaved exclusively at one bond. The double cleavages of Dns-PLALWAR and Dns-PLALFAR by SCD are in marked contrast to the close structurally related matrilysin. A notable feature of SCD catalysis agrees with the structural data that the S1' pocket of SCD is deeper than that of matriysin. The differences observed between SCD and matrilysin may form the basis of understanding the structural relationships and substrate specificities of the MMP family in vivo.

• Korean Journal of Organic Agriculture
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• v.23 no.4
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• pp.875-886
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• 2015

The upland soils (56 samples) from organic farms in Gyeonggi-do (12 sites), Gangwon-do (8 sites), Chungcheong-do (14 sites), Gyeongsang-do (4 sites), Jeollado (18 sites) in Korea were collected and their physical and chemical properties were analyzed by RDA's methods. In the results of physical property, the bulk density of soils averaged $1.14Mgm^{-3}$ (surface soil), $1.38Mgm^{-3}$ (subsoil), respectively. The porosity of them was 57%, 48%. Organically managed soil's (OS) bulk density was lower than conventional soil's but OS's porosity was a little higher than conventionally managed soil in surface soil. The depth of plough layer in organically managed soils was 21.2 cm indicating that the organic farming had good effect on soil physical property. In the results of chemical property, the surface soil pH was 6.9 and the contents of organic matter (OM) was $26gkg^{-1}$, available phosphate (Avail. $P_2O_5$) was $554mgkg^{-1}$, exchangeable calcium (Exch. Ca) was $8.9cmol_ckg^{-1}$, exchangeable potassium (Exch. K) was $0.89cmol_ckg^{-1}$, exchangeable magnesium (Exch. Mg) was $2.0cmol_ckg^{-1}$. The subsoil pH was 6.8 and the contents of OM was $21gkg^{-1}$, avail. $P_2O_5$ was $491mgkg^{-1}$, exch. Ca was $7.9cmol_ckg^{-1}$, exch. K was $0.68cmol_ckg^{-1}$, exch. Mg was $1.8cmol_ckg^{-1}$. The nutrient accumulation emerged in organic farming. Compared to the optimum nutrient range for the conventional upland soils, the exceed rate of pH, OM, available phosphate, and exchangeable Ca, K, and Mg was 79, 52, 64, 84, 66% and 55%, respectively, which mainly resulted from the over-application of lime materials or livestock manure compost. With these results it is suggested that organic farm need to reduce the use of inputs, which make soil alkalification or nutrient accumulation. More study on effects of inputs on lowering soil pH from alkalification could help organically managed soil to be improved.