• Microbiology and Biotechnology Letters
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• v.29 no.4
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• pp.201-205
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• 2001

A bacteria strain producing extracellular $\beta$-mannanase was isolated from soil and was identified as Aeromonas sp. A genomic DNA library constructed from Aeromonas, sp that secrets a $\beta$-mannanase was screened for mannan hydrolytic acticity. Recombinant $\beta$-mannanase activity was detercted on the basis of the clear zones around Escherichia coli colonies grown on a LB medium supplemented locust bean gum, EcoRI restriction analysis of plasmid prepared from recombinant E. coli which showed a $\beta$-mannanase activity revealed 10 kb DNA insert, The optimum pH and temperature for the activity of reconmbinant $\beta$-mannanase were 6.0 and $50^{\circ}C$ respectively and were identical to those of the native enzyme.

• YAKHAK HOEJI
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• v.37 no.1
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• pp.89-94
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• 1993

In order to find out a proper connecting bridge between 5-fluorouracil(5-FU) and a macromolecule such as a polypeptide, potentially hydrolytic N$^{1}$-derivartives of 5-FU have been systhesized and evaluated for their biological activity. When tested with in vitro leukemic L$_{1210}$ cells all the obtained derivartives exhibited slightly higher antitumor activity than the parent 5FU. Among them the N$^{1}$ -carbamoyl analogue 2 and N$^{1}$-acetamido analogue 6b showed 50% inhibition of the L$_{1210}$ cell growth at the concentrations of 5.01$\times$10$^{-8}$M and 1.03$\times$10$^{-7}$M, respectively. When tested against sarcoma 180 tumor cells inoculated into mice, the compounds 2 and 6b exhibited, respectively, 62% and 54% inhibition of the solid tumor growth at the 5-time doses of 100 mg/kg/day. Both compounds, N$^{1}$-carbamoyl analogue 2 and N$^{1}$-acetamido analogue 6b, realeased the parent 5-FU when incubated in the L$_{1210}$ cell cultural media for 5 hrs.

• Journal of Soil and Groundwater Environment
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• v.20 no.6
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• pp.37-45
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• 2015

This study was conducted to determine the toxic effect of TNT and RDX on indigenous soil microbes by measuring enzymatic activity. Denitrification activity, dehydrogenase activity, phosphatase activity, and fluorescein diacetate hydrolytic activity were determined for military firing range, field, and paddy soils exposed to TNT, and RDX from 0 to 1,000 mg/kg and 0 to 4,000 mg/kg, respectively, for 2, 4, and 8 weeks. Soil microbial enzymatic activities decreased with higher TNT and RDX concentration and longer exposure time. Microbial enzymatic activities of firing range soil were higher than field and paddy soils, indicating that indigenous microbes in firing range might have been adapted to TNT and RDX due to pre-exposure of the explosives. In addition, the toxicity of TNT and RDX decreased with higher organic matter because TNT and RDX tend to absorb to soil organic matter. No Observable Effect Concentration (NOEC) values of each microbial enzymatic activity were derived by the geometric mean of NOECs from exposure times (2, 4, and 8 weeks) and soil types (firing range, field, paddy soil). The derived NOECs ranged from 45.3 to 55.2 mg/kg for TNT and 286 to 309 mg/kg for RDX.

• Journal of Microbiology and Biotechnology
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• v.19 no.10
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• pp.1169-1175
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• 2009

An antifungal chitinase, ChiCW, produced by Bacillus cereus 28-9 is effective against conidial germination of Botrytis elliptica, the causal agent of lily leaf blight. ChiCW as a modular enzyme consists of a signal peptide, a catalytic domain, a fibronectin type-III-like domain, and a chitin-binding domain. When two C-terminal domains of ChiCW were truncated, $ChiCW{\Delta}FC$ (lacking the chitin-binding domain and fibronectin type III-like domain) lost its antifungal activity. Since $ChiCW{\Delta}C$ (lacking the chitin-binding domain) could not be expressed in Escherichia coli as $ChiCW{\Delta}FC$ did, a different strategy based on protein engineering technology was designed to investigate the involvement of the chitin-binding domain of ChiCW ($ChBD_{ChiCW}$) in antifungal activity in this study. Because ChiA1 of Bacillus circulans WL-12 is a modular enzyme with a higher hydrolytic activity than ChiCW but not inhibitory to conidial germination of Bo. elliptica and the similar domain composition of ChiA1 and ChiCW, the C-terminal truncated derivatives of ChiA1 were generated and used to construct chimeric chitinases with $ChBD_{ChiCW}$. When the chitin-binding domain of ChiA1 was replaced with $ChBD_{ChiCW}$, the chimeric chitinase named ChiAAAW exhibited both high enzyme activity and antifungal activity. The results indicate that $ChBD_{ChiCW}$ may play an important role in the antifungal activity of ChiCW.

• Applied Chemistry for Engineering
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• v.18 no.3
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• pp.218-226
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• 2007

The stereoselective synthesis of chiral terminal epoxides is of immense academic and industrial interest due to their utility as versatile starting materials as well as chiral intermediates. In this study, new dinuclear chiral Co (salen) complexes bearing gallium-, indium- and tallium-chloride have been synthesized and characterized. The mass and EXAFS spectra provided the direct evidence of formation of dinuclear complex. Their catalytic activity and selectivity have been demonstrated for the asymmetric ring opening of various terminal epoxides having ether or ester groups by hydrolytic kinetic resolution technology. The easily prepared dimeric complexes exhibited very high enantioselectivity for the asymmetric ring opening of epoxides with $H_2O$ nucleophile, providing enantiomerically enriched terminal epoxides (> 99% ee). The dimeric structured chiral salen showed remarkably enhanced reactivity and may be employed substantially lower loadings than its monomeric analogues. The system described in this work is very efficient for the synthesis of chiral epoxide and 1,2-diol intermediates

• The Plant Pathology Journal
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• v.33 no.2
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• pp.170-183
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• 2017

Bacterial fruit blotch (BFB), which is caused by Acidovorax citrulli, is a serious threat to watermelon growers around the world. The present study was conducted to screen effective rhizobacterial isolates against 35 different A. citrulli isolates and determine their efficacy on BFB and growth parameters of watermelon. Two rhizobacterial isolates viz. Paenibacillus polymyxa (SN-22), Sinomonas atrocyanea (NSB-27) showed high inhibitory activity in the preliminary screening and were further evaluated for their effect on BFB and growth parameters of three different watermelon varieties under greenhouse conditions. The greenhouse experiment result revealed that SN-22 and NSB-27 significantly reduced BFB and had significant stimulatory effect on total chlorophyll content, plant height, total fresh weight and total dry weight compared to uninoculated plants across the tested three watermelon varieties. Analysis of the 16S ribosomal RNA (rRNA) sequences revealed that strains SN-22 belong to P. polymyxa and NSB-27 to S. atrocyanea with the bootstrap value of 99% and 98%, respectively. The isolates SN-22 and NSB-27 were tested for antagonistic and PGP traits. The result showed that the tested isolates produced siderophore, hydrolytic enzymes (protease and cellulose), chitinase, starch hydrolytic enzymes and they showed phosphate as well as zinc solubilizing capacity. This is the first report of P. polymyxa (SN-22) and S. atrocyanea (NSB-27) as biocontrol-plant growth promoting rhizobacteria on watermelon.

• Journal of Microbiology and Biotechnology
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• v.10 no.2
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• pp.258-263
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• 2000

2-Hydroxy-6-oxo-6phenylhexa-2,4-dienoate (HOPDA) hydrolase catalyzes the hydrolytic cleavage of HOPDA to bemzpate and 2-hydroxypenta-2, 4-dienoate (HPD) during microbial catabolism of biphenyl and polychlorinated biphenyls. A HOPDA hydrolase gene (pcbD) was isolated from the genomic library of Pseudomonas sp. P20 and designated as pCNUO1201; a 7.5-kb XbaI DNA fragment from Pseudomonas sp. P20 was inserted into the pBluescript SK(+) XbaI site. E. coli HB101 harboring pCNU1201 exhibited HOPDA hydrolase activity. The open reading frame (ORF) corresponding to the pcbD gene consisted of 855 base pairs with an ATG initiation codon and a TGA termination codon. The ORF was preceded by a rebosome-binding sequence of 5'-TGGAGC-3' and its G+C content was 55 mol%. The pcbD gene of Pseudomonas sp. P20 was located immedeately downstream of the pcbC gene encoding 2,3- dihydroxybiphenyl 1,2-dioxygenase, and approximately 4-kb upstream of the pcbE gene encoding HPD hydratase. The pcbK gene was able to encode a polypeptide with a molecular weight of 31,732 containing 284 amino acid residues. The deduced amino acid sequence of the HOPDA hydrolase of Pseudomonas sp. P20 exhibited high identity (62%) with those of the HOPDA hydrolases of P. putida KF715, P. pseudoalcaligenes KF707, and Burkholderia cepacia LB400, and also significant homology with those of other hydrolytic enzymes including esterase, transferase, and peptidase.

• Applied Chemistry for Engineering
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• v.18 no.4
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• pp.330-336
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• 2007

In this study, new dinuclear chiral Co (salen) complexes bearing $BF_3$ have been synthesized and their properties as the asymmetric catalyst have been examined. The NMR, UV and ESCA analyses were performed to determine the structure of synthesized catalysts. Their catalytic activity and selectivity have been demonstrated for the asymmetric ring opening of various terminal epoxides by hydrolytic kinetic resolution technology. The easily prepared dimeric complexes exhibited very high enantioselectivity for the asymmetric ring opening of epoxides with $H_2O$ nucleophile, providing enantiomerically enriched terminal epoxides (> 99 %ee). The dimeric structured chiral salen showed remakablely enhanced reactivity and may be employed substantially lower loadings than its monomeric analogues, and in addition no racemization happened during the separation of product epoxides. The system described in this work is very efficient for the sinthesis of chiral epoxide and 1,2-diol intermediates.

• Korean Journal of Agricultural Science
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• v.40 no.3
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• pp.221-226
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• 2013

Degrees of hydrolysis by alkaline protease produced from Serratia marcescens S3-R1 is 3.95-6.30% of whey proteins during 5, 15, 30, 60, 90, 120,180, 240 min incubation at $40^{\circ}C$. Proteolytic pattern of the whey proteins showed that various low molecular weight peptides were generated during the incubation periods. The biological function of in Raw 264.7 cells treated with whey protein hydrolytic peptides, anti-inflammatory effect showed exhibit in the expression of pro-inflammatory cytokines such as TNF-${\alpha}$, IL-6, COX-2 and iNOS by PCR analysis. COX-2 and iNOS gene expression inhibited in Raw 264.7 cells on whey protein hydrolysates below 3,000 dalton. The protease from Serratia marcescens S3-R1 showed a potential in production of low molecular weight whey protein hydrolysates which could be used for industrial application.

• Korean Chemical Engineering Research
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• v.46 no.4
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• pp.769-776
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• 2008

The stereoselective synthesis of chiral terminal epoxide is of immense interest due to their utility as versatile starting materials as well as chiral intermediates. In this study, new chiral Co(salen) complexes bearing cobalt(II) chloride, iron(III) chloride and zinc(II) nitrate have been synthesized and characterized. The mass and EXAFS spectra provided the direct evidence of formation of complex. Their catalytic activity and selectivity have been demonstrated for the asymmetric ring opening of terminal epoxides such as styrene oxide and phenylglycidylether by hydrolytic kinetic resolution technology and for the synthesis of glycidyl buthylate. The easily prepared complexes exhibited very high enantioselectivity for the asymmetric ring opening of epoxides with $H_2O$ nucleophile, providing enantiomerically enriched terminal epoxides (>99% ee). The newly synthesized chiral salen showed remakablely enhanced reactivity with substantially low loadings. The system described in this work is very efficient for the sinthesis of chiral epoxide and 1,2-diol intermediates.