• Journal of Korean Society on Water Environment
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• v.25 no.3
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• pp.419-424
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• 2009

Characteristics of humic substances on the changes in dissolved organic matter (DOM) characteristics by biodegradation was investigated using three types of the artificial water samples composed of glucose and Suwannee River fulvic acid (SRFA). Some selected DOM characteristics including the specific UV absorbance (SUVA), the synchronous fluorescence spectra and the molecular weight (MW) were compared for the artificial water samples before and after 28-day microbial incubation. The changes of the DOM characteristics were minimal for SRFA during the incubation whereas they were significant for glucose. SUVA, dissolved organic carbon (DOC)-normalized fluorescence intensity, and MW values of glucose increased, suggesting that such labile organic compounds could be exclusively transformed into more humidified materials by biodegradation. For glucose-SRFA mixture, the selected DOM characteristics were greater than those estimated using the assumption that the individual changes of either glucose or SRFA are conservative for the mixture of the two materials. Our results suggest that the presence of humic substances (HS) may lead to the enhancement of the formation of refractory organic materials during biodegradation of labile compounds. Detailed analyses of size exclusion chromatography (SEC) revealed that the enhancement occurred for the DOM mixture with a MW range between 500 Da to 4000 Da.

• Journal of Plant Biotechnology
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• v.42 no.4
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• pp.342-349
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• 2015

Kiwifruit is a new fruit crop that was commercialized in the late 1970s. Recently, its cultivation and consumption have increased rapidly worldwide. Kiwifruit is a dioecious, deciduous, and climbing plant having fruit with hairs and various flesh colors and a variation in ploidy level; however, the industry consists of very simple cultivars or genotypes. The need for efficient cultivar improvement together with the evolutional and biological perspectives based on unique plant characteristics, have recently encouraged genome analysis and bioinformatics application. The draft genome sequence and chloroplast genome sequence of kiwifruit were released in 2013 and 2015, respectively; and gene annotation has been in progress. Recently, transcriptome analysis has shifted from previous ESTs analysis to the RNA-seq platform for intensive exploration of controlled genetic expression and gene discovery involved in fruit ascorbic acid biosynthesis, flesh coloration, maturation, and vine bacterial canker tolerance. For improving conventional breeding efficiency, molecular marker development and genetic linkage map construction have advanced from basic approaches using RFLP, RAPD, and AFLP to the development of NGS-based SSR and SNP markers linked to agronomically important traits and the construction of highly saturated linkage maps. However, genome and transcriptome studies have been limited in Korea. In the near future, kiwifruit genome and transcriptome studies are expected to translate to the practical application of molecular breeding.

• Journal of Microbiology and Biotechnology
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• v.13 no.6
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• pp.881-891
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• 2003

Paenibacillus polymyxa is a plant growth-promoting rhizobacterium (PGPR) which can be used for biological control of plant diseases. Several bacterial strains were isolated from rotten roots of Korean ginseng (Panax ginseng C. A. Meyer) that were in storage. These strains were identified as P. polymyxa, based on a RAPD analysis using a P. polymyxa-specific primer, cultural and physiological characteristics, an analysis utilizing the Biolog system, gas chromatography of fatty acid methyl esters (GC-FAME), and the 16S rDNA sequence analysis. These strains were found to cause the rot in stored ginseng roots. Twenty-six P. polymyxa strains, including twenty GBR strains, were phylogenetically classified into two groups according to the ERIC and BOX-PCR analyses and 16S rDNA sequencing, and the resulting groupings systematized to the degrees of virulence of each strain in causing root rot. In particular, highly virulent GBR strains clustered together, and this group may be considered as subspecies or biovar. The virulence of the strains seemed to be related to their starch hydrolysis enzyme activity, but not their cellulase or hemicellulase activity, since strains with reduced or no starch-hydrolytic activity showed little or no virulence. Artificial inoculation of the highly virulent strain GBR-1 onto the root surfaces of Korean ginseng resulted in small brown lesions which were sunken and confined to the outer portion of the root. Ginseng root discs inoculated in vitro or two-year-old roots grown in soil drenched with the inoculum developed significant rot only when the inoculum density was $10^{6}-10^{7}$ or more colony-forming units (CFU) per ml. These results suggest that P. polymyxa might induce ginseng root rot if their population levels are high. Based on these results, it is recommended that the concentration of P. polymyxa should be monitored, when it is used as a biocontrol agent of ginseng, especially in the treatment of stored roots.

• Microbiology and Biotechnology Letters
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• v.30 no.2
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• pp.135-141
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• 2002

This study was carried out to isolate antagonistic bacterium against Sclerotium cepivorum causing Allium fistulosum white rot. Total of 146 strains were isolated from A. fistulosum roots. The isolates were screened for antagonism to S. cepivorum and the isolated strain No. AL-1 was selected among these bacteria. It was identified as Serratia plymuthica based on morphological and physiological characteristics according to the Bergey's mannual of systematic bacteriology and 16S rDNA sequences methods. Serratia plymuthica AL-1 showed broad spectrum of antifungal activities against plant pathogenic fungi Alternaria altrata, Colletotrichum gleosporioids, Phoma sp., Rhizoctonia solani, Sclerotinia sclerotiorum, Stemphylium solani, Fusarium oxysporium niveum but not inhibited Didymella bryoniae. When S. plymuthica AL-1 cultivated in the TSB medium containing 1％ colloidal chitin, the high molecular fraction (>10 kDa) have chitinase activity (3.2 units/ml) and the low molecular fraction (<10 kDa) have not chitinase activity. Oppositely, after heat treatment (80℃ for 30 min) of the cultivation supernatant, the high molecular fractions have not antifungal activity but the low molecular fractions have antifungal activity.

• Journal of Genetic Medicine
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• v.10 no.1
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• pp.38-42
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• 2013

Purpose: The purpose of this study was to assess the characteristics of achondroplasia (ACH) diagnosed in fetuses or neonates and to evaluate the usefulness of a molecular genetic testing to confirm ACH. Materials and Methods: The medical and ultrasonographic records of 16 pregnant women, who had molecular genetic testing for ACH performed on their fetus or neonate at the Cheil General Hospital between February 1999 and April 2013, were retrospectively analyzed. Detection of G1138A and G1138C mutations of the fibroblast growth factor receptor 3 (FGFR3) gene was accomplished by polymerase chain reaction - restriction fragment length polymorphism analysis. Results: Of the eight fetuses and two neonates who were suspected of having ACH during pregnancy, four fetuses and one neonate was confirmed to have ACH and they all carried the heterozygous G1138A mutation. Out of 6 cases which had a history of ACH in prior pregnancies, three had genetic information for the previous fetuses while the other three did not. All six fetuses had no mutations at G380R. However, the one fetus of pregnant woman with non-confirmed ACH showed shortened long bone on ultrasound thereafter and the fetus was identified as having oto-spondylo-megaepiphyseal dysplasia after birth. Conclusion: Korean patients with achondroplasia have the heterozygous G1138A mutation that is most commonly defined in other countries. Molecular genetic evaluations of ACH are helpful not only for establishing diagnosis but for appropriate counseling with subsequent pregnancies.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.12
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• pp.6139-6144
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• 2012

Aims: Mammalian target of rapamycin (mTOR) is master regulator of the PI3K/Akt/mTOR pathway and plays an important role in NSCLCs. Here we characterized mRNA and protein expression levels of mTOR and its functional associated molecules including PTEN, IGF-1R and 4EBP1 in surgically resected NSCLCs. Methods: Fifty-four patients with NSCLCs who underwent pulmonary resection were included in current study. mRNA levels of mTOR, PTEN, IGF-1R, and 4EBP1 were evaluated by RT-PCR and protein expression of mTOR, PTEN, and IGF-1R by immunohistochemistry (IHC). Association of expression of the relevant molecules with clinical characteristics, as well as correlations between mTOR and PTEN, 4EBP1 and IGF-1R were also assessed. Results: The results of RT-PCR showed that in NSCLCs, the expression level of mTOR increased, while PTEN, 4EBP1 and IGF-1R decreased. Statistical analysis indicated high IGF-1R expression was correlated with advanced clinical stage (stage III) and PTEN expression was reversely associated with tumor size (P=0.16). The results of IHC showed mTOR positive staining in 51.8% of cases, while IGF-1R positive staining was found in 83.3% and loss of PTEN in 46.3%. Protein expression of mTOR was correlated with its regulators, PTEN and IGF-1R, to some extent. Conclusions: Abnormal activation of mTOR signaling, high expression of IGF-1R, and loss of PTEN were observed in resected NSCLC specimens. The poor expression agreement of mTOR with its regulators, PTEN, and IGF-1R, implied that combination strategy of mTOR inhibitors with other targets hold significant potential for NSCLC treatment.

• Journal of the Korea Concrete Institute
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• v.18 no.4 s.94
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• pp.489-496
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• 2006

Graft copolymerized polycarboxylate(PC)-type superplasticizers which have carboxylic acid with $\pi$ bond among the molecular structure and polyethyleneglycol methyl ether methacrylate(PMEM) were synthesized by free radical reaction. To investigate their chemical structures and molecular weights, PCs were analyzed by FT-IR(fourier transform spectrometer), C-NMR(nuclear magnetic resonance spectrometer) and GPC(gel permeation chromatograpy). When types of carboxylic acids(methacrylic acid, acrylic acid, maleic anhydride, and itaconic acid) and molar ratios of carboxylic acid/PMEM) were varied, adsorptive and fluid characteristics in cement paste were discussed. As the molar ratio of carboxylic acid/PMEM) was higher, amount adsorbed on the cement particles and the fluidity of cement paste by mini-slump spread testing method were increased. When main chain of PC was methacrylic acid, a larger amount was adsorbed on the cement particles. PCs with acrylic acid as main chain showed higher dispersing power. However, it was confirmed that PCs with dicarboxylic acids(maleic anhydride, itaconic acid) didn't have good adsorption and dispersibility.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.5
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• pp.388-392
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• 2000

To improve functionality and characteristics of alginate from the sea tangle, Laminaria japonicus, partially depolymerized alginates (HAG-10, average molecular weight 10,000; HAG-50, average molecular weight 50,000; HAG-100, average molecular weight 100,000) were obtained with hydrolysis of alginate by heating at $12^{\circ}C$. Effects of the depolymerization on physicochemical properties were investigated in the antimutagenicity and binding capacity of cholesterol, glucose and cadmium. In the Ames mutagenicity test using Salmonella typhimurium TA 100, HAG-10, HAG-50, HAG-100 and intact alginate reduced effectively the mutagenicities induced by aflatoxin $B_1 (AFB_1)$ and N-methyl-N'-nitro-N-nitrosoguanidine(MNNG) and HAG-10 showed the strongest antimutagenicity among the tested samples. The binding capacity of cholesterol, glucose and cadmium at different pH in vitro depended highly on molecular weight of alginate, and the changes in binding capacity at different pH was not different.

• Korean Journal of Food Science and Technology
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• v.27 no.3
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• pp.420-427
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• 1995

This study was conducted to investigate the preservative effect of low molecular weight chitosans on kimchi(2% salt concentration) during fermentation at $20^{\circ}C$. The pH and total acidity of control kimchi were lower and higher, respectively than those of kimchi samples containing chitosan. Reducing sugar content tended to be lower in control kimchi than in kimchi samples containing chitosan until 6 days of fermentation. Malic acid content was lower in control kimchi than in kimchi samples containing chitosan until 4 days of fermentation. Succinic acid content was higher in control kimchi than in kimchi samples containing chitosan at the 2 days of fermentation. Content of lactic and acetic acid also was higher in control kimchi than in kimchi samples containing chitosan at the 4 days of fermentation. The number of total microorganisms and those of microorganisms of Leuconostoc genus and Lactobacillus plantarum were higher in control kimchi than in kimchi samples containing chitosan. The number of microorganisms of Leuconostoc genus was lower in kimchi samples containing chitosan with the lower molecular weight chitosan than those with the higher molecular weight chitosan. Intensity of sensory sour taste and staled flavor were higher in control kimchi than in kimchi samples containing chitosan. There was not much difference in sensory firmness among kimchi samples, but control kimchi was evaluated slightly weaker than kimchi samples containing chitosan. Off-flavor was evaluated as weak in all the kimchi samples.

• Biomolecules & Therapeutics
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• v.3 no.4
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• pp.266-272
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• 1995

The analysis of membrane receptors for hormones and neurotransmitters has progressed considerably by pharmacological and biochemical means and more recently through the use of specific antibodies. To generate and characterize a moloclonal antibody against $\beta$-adrenergic receptor, a synthetic $\beta$2-adrenergic receptor peptide (Phe-Gly-Asn-Phe-Trp-Cys-Phe-Trp-Thr-Ser-lle-Asp-Val-Leu) which may comprise part of $\beta$-adrenergic receptor ligand binding pocket was coupled to Keyhole Limpet Hemocyanin (KLH) and used as an immunogen. Male BALB/C mice were immunized with this antigen and the immunized spleen was fused with myeloma SP2/0-Ag14 cells to produce monoclonal antibodies. Two clones were obtained but one of monoclonal antibodies, mAb5G09, was used throughout in this study because the other clone, mAb5All showed weak immunoreactivity against KLH as well. The mouse monoclonal antibody mAb5G09 produced in this study showed immunoreactivity to peptide-KLH conjugates and also to human A43l cells and guinea pig lung $\beta$2-adrenergic receptor as revealed by ELISA and western blot. In the course of determination of the effects of mAb5G09 on $\beta$-receptor ligand binding, it was observed that mAb5G09 specifically bound $\beta$-adrenergic radioligand [$^3$H]dihydroalprenolol (DHA) with a dissociation constant (Kd) of 60 nM. The [$^3$H]DHA binding activity of mAb5G09 had characteristics of immunoglobulins and the binding activity was not observed in the control anti-KLH monoclonal antibody. The monoclonal antibody, mAb5G09 produced in this study may provide useful models for the study of the structure of receptor binding sites.