• Journal of Aquaculture
• /
• v.17 no.1
• /
• pp.69-80
• /
• 2004

The objective of the present study was to analyze genetic distances, variation and characteristics of individuals in rainbow trout, Oncorhynchus mykis using amplified fragment length polymorphism (AFLP) method as molecular genetic technique, to detect AFLP band patterns as genetic markers, and to compare the efficiency of agarosegel electrophoresis (AGE) and polyacrylamide gel electrophoresis (PAGE), respectively. Using 9 primer combinations, a total of 141 AFLP bands were produced, 108 bands (82.4%) of which were polymorphic in AGE. In PAGE, a total of 288 bands were detected, and 220 bands (76.4%) were polymorphic. The AFLP fingerprints of AGE were different from those of PAGE. Separation of the fragments with low molecular weight and genetic polymorphisms revealed a distinct pattern in the two gel systems. In the present study, the average bandsharing values of the individuals between two populations apart from the geographic sites in Kangwon-do ranged from 0.084 to 0.738 of AGE and PAGE. The bandsharing values between individuals No.9 and No. 10 showed the highest level within population, whereas the bandsharing values between individuals No.5 and No.7 showed the lowest level. As calculated by bandsharing analysis, an average of genetic difference (mean$\pm$SD) of individuals was approximately 0.590$\pm$0.125 in this population. In AGE, the single linkage dendrogram resulted from two primers (M11+H11 and M13+H11), indicating six genetic groupings composed of group 1 (No.9 and 10), group 2 (No. 1, 4, 5, 7, 10, 11, 16 and 17), group 3 (No. 2, 3, 6, 8, 12, 15 and 16), group 4 (No.9, 14 and 17), group 5 (No. 13, 19, 20 and 21) and group 6 (No. 23). In AGE, the genetic distances among individuals of between-population ranged from 0.108 to 0.392. In AGE, the shortest genetic distance (0.108) displaying significant molecular differences was between individuals No.9 and No. 10. Especially, the genetic distance between individuals No. 23 and the remnants among individuals within population was highest (0.392). Additionally, in the cluster analysis using the PAGE data, the single linkage dendrogram resulted from two primers (M12+H13 and M11+H13), indicating seven genetic groupings composed of group 1 (No. 15), group 2 (No. 14), group 3 (No. 11 and 12), group 4 (No.5, 6, 7, 8, 10 and 13), group 5 (No.1, 2, 3 and 4), group 6 (No.9) and group 7 (No. 16). By comparison with the individuals in PAGE, genetic distance between No. 10 and No. 7 showed the shortest value (0.071), also between No. 16 and No. 14 showed the highest value (0.242). As with the PAGE analysis, genetic differences were certainly apparent with 13 of 16 individuals showing greater than 80% AFLP-based similarity to their closest neighbor. The three individuals (No. 14, No. 15 and No. 16) of rainbow trout between two populations apart from the geographic sites in Kangwon-do formed distinct genetic distances as compared with other individuals. These results indicated that AFLP markers of this fish could be used as genetic information such as species identification, genetic relationship or analysis of genome structure, and selection aids for genetic improvement of economically important traits in fish species.

• Korean Journal of Soil Science and Fertilizer
• /
• v.39 no.4
• /
• pp.195-203
• /
• 2006

An antagonistic strain, Burkholderia MP-1, showed antimicrobial activity against various filamentous plant pathogenic fungi, yeasts and food borne bacteria (Gram-positive and Gram-negative). The nucleotide sequence of the 16S rRNA gene (1491 pb) of strain MP-1 exhibited close similarity (99-100%) with other Burkholderia 16S rRNA genes. Isolation of the antibiotic substances from culture broth was fractionated by ethyl acetate (EtOAc) solvent and EtOAc-soluble acidic fraction. The antibiotic substances were purified through a silica gel, Sephadex LH-20, ODS column chromatography, and high performance liquid chromatography, respectively. Four active substances were identified as phenylacetic acid, hydrocinnamic acid, 4-hydroxyphenylacetic acid and 4-hydroxyphenylacetate methyl ester by gas chromatographic-mass spectrum analysis. The minimum inhibition of concentration (MIC) of each active compound inhibited the growth of the microorganisms tested at 250 to $2500{\mu}g\;ml^{-1}$. The antimicrobial activity of crude acidic fraction at 1 mg of dry weight per 6 mm paper disc was more effective than authentic standard mixture (four active substances were mixed with the same ratio as acidic fraction) over a wide range of bacterial test.

• Journal of Life Science
• /
• v.17 no.9 s.89
• /
• pp.1197-1203
• /
• 2007

A genomic DNA library of the bacterium Paenibacillus sp. DG-22 was constructed and the ${\beta}-xylosi-dase-positive$ clones were identified using the fluorogenic substrate $4-methylumbelliferyl-{\beta}-D-xylopyr-anoside$ $({\beta}MUX)$. A recombinant plasmid was isolated from the clone and 4.3-kb inserted DNA was sequenced. The ${\beta}-xylosidase$ gene (xylA) was comprised of a 2,106 bp open reading frame (ORF) en-coding 701 amino acids with a molecular weight of 78,710 dalton and a pI of 5.0. The deduced amino acid sequence of the xylA gene product had significant similarity with ${\beta}-xylosidases$ classified into family 52 of glycosyl hydrolases. The xylA gene was subcloned into the pQE60 expression vector to fuse with six histidine-tag. The recombinant ${\beta}-xylosidase$ $(XylA-H_6)$ was purified to homogeneity by heat-treatment and immobilized metal affinity chromatography. The pH and temperature optima of the $XylA-H_6$ enzyme were pH 5.5-6.0 and $60^{\circ}C$, respectively.

• BMB Reports
• /
• v.38 no.6
• /
• pp.668-675
• /
• 2005

A full-length cDNA encoding taxadiene synthase (designated as TmTXS), which catalyzes the first committed step in the Taxol biosynthetic pathway, was isolated from young leaves of Taxus media by rapid amplification of cDNA ends (RACE). The full-length cDNA of TmTXS had a 2586 bp open reading frame (ORF) encoding a protein of 862 amino acid residues. The deduced protein had isoelectric point (pI) of 5.32 and a calculated molecular weight of about 98 kDa, similar to previously cloned diterpene cyclases from other Taxus species such as T. brevifolia and T. chinenisis. Sequence comparison analysis showed that TmTXS had high similarity with other members of terpene synthase family of plant origin. Tissue expression pattern analysis revealed that TmTXS expressed strongly in leaves, weak in stems and no expression could be detected in fruits. This is the first report on the mRNA expression profile of genes encoding key enzymes involved in Taxol biosynthetic pathway in different tissues of Taxus plants. Phylogenetic tree analysis showed that TmTXS had closest relationship with taxadiene synthase from T. baccata followed by those from T. chinenisis and T. brevifolia. Expression profiles revealed by RT-PCR under different chemical elicitor treatments such as methyl jasmonate (MJ), silver nitrate (SN) and ammonium ceric sulphate (ACS) were also compared for the first time, and the results revealed that expression of TmTXS was all induced by the tested three treatments and the induction effect by MJ was the strongest, implying that TmTXS was high elicitor responsive.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.36 no.11
• /
• pp.1413-1420
• /
• 2012

To predict the dynamics behavior, running stability, etc. of a railway vehicle and to understand its physical characteristics, analytical methods are used for the testing and manufacturing of a scale model along with numerical simulations in developed countries (England, France, Japan, etc.). The test of the dynamics characteristics of full-scale models is problematic in that it is expensive and time-consuming because an entire large-scale test plant needs to be constructed, difficulties are involved in the test configuration, etc. To overcome these problems, an analytical study involving dynamics tests and computer simulations using a scaled bogie model that applies the laws of similarity was carried out. In this study, we performed stability analysis on a 1/5 small scaled bogie for parameters such as the running speed and carbody weight by using an analysis model. Furthermore, we verified the reliability by using a small-scaled derailment simulator and examined the dynamic characteristic of the 1/5 small scaled bogie.

• The Korean Journal of Pesticide Science
• /
• v.11 no.4
• /
• pp.289-298
• /
• 2007

In order to set ADIs for pesticides registered for use in Korea, an analysis of guidelines on setting ADIs and ADIs established by international bodies and advanced countries was conducted General guidelines on the derivation ADIs are very similar among regulatory authorities. However, there were large differences in the ADIs' setting status and ADI values set for some individual pesticides. ADIs were established for 213 pesticides in UN, 332 in USA, 230 in Japan, 219 in UK and 435 in EU and Australia. Of the established ADIs in other countries, 87 to 252 pesticides were the pesticides registered in Korea depending countries. The number of lowest ADIs depending countries was 32 in USA, 23 in Japan, 6 in EU and Australia. The key target organs and endpoints used for setting ADIs were in the order of enzyme inhibition, body weight change and adverse effect on liver. The number of ADIs used for setting MRLs in Korea was high in the order of JMPR, Japan and USA. ADIs of EU and JMPR had highest similarity among bodies investigated. By referring to the guidances investigated at this study, guideline for setting ADI and ADIs for 64 pesticides registered in Korea were proposed.

• Korean Journal of Food Science and Technology
• /
• v.36 no.1
• /
• pp.105-110
• /
• 2004

Microorganism (strain DF 218) producing thermostable pretense was isolated from Korean soil and compost. It was Gram-positive, rod-shaped, aerobic, and spore-forming with yellowish white colony color, Temperature range for growth at pH 6.5 was $30-65^{\circ}C$, with optimum growth at $60^{\circ}C$. pH range for growth at $60^{\circ}C$ was 5-7 with optimum of 6.5, which indicates strain DF 218 to be thermophilic. The 16S rDNA sequence of strain DF 218 had 95% sequence similarity with that of Bacillus flexus. Based on physiological properties and phylogenetic analysis, we proposed the isolated strain as Bacillus sp. DF 218. Pretense was produced aerobically at $60^{\circ}C$ for 32 hr in a medium (pH 6.5) containing 1% each trypton, glucose, and NaCl. Its molecular weight was estimated as 61 kDa, with optimum temperature and pH of $60^{\circ}C$ and 7.5, respectively.

• Microbiology and Biotechnology Letters
• /
• v.34 no.4
• /
• pp.311-317
• /
• 2006

Using PCR amplification, we cloned a cellulase gene (ce/H) from the Bacillus subtilis AH18 which has plant growth-promoting activity and antagonistic ability against pepper blight caused by Phytophthora capsici. The 1.6 kb PCR fragment contained the full sequence of the cellulase gene and the 1,582 bp gene deduced a 508 amino acid sequence. Similarity search in protein database revealed that the cellulase of B. subtilis AH18 was more than 98% homologous in the amino acid sequence to those of several major Bacillus spp. The ce/H was expressed in E. coli under an IPTG inducible lac promoter on the vector, had apparent molecular weight of about 55 kDa upon CMC-SDS-PAGE analysis. Partially purified cellulase had not only cellulolytic activity toward carboxymethyl-cellulose (CMC) but also insoluble cellulose, such as Avicel and filter paper (Whatman No. 1). In addition, the cellulase could degrade a fungal cell wall of Phytophthora capsici. The optimum pH and temperature of the ce/H coded cellulase were determined to be pH 5.0 and $50^{\circ}C$. The enzyme activity was activated by $AgNO_3$ or $CoCl_2$. However its activity was Inhibited by $HgC1_2$. The enzyme activity was activated by hydroxy urea or sodium azide and inhibited by CDTA or EDTA. The results indicate that the cellulase gene, ce/H is an antifungal mechanism of B. subtilis AH18 against phytophthora blight disease in red-pepper.

• Journal of KIISE:Computing Practices and Letters
• /
• v.15 no.3
• /
• pp.189-199
• /
• 2009

The amount of information on the Web is explosively growing as the Internet gains in popularity. However, only a small portion of the information on the Web is truly relevant or useful to the user. Thus, offering suitable information according to user demand is an important subject in information retrieval. In e-commerce, the recommender system is essential to revitalize commercial transactions, raise user satisfaction and loyalty towards the information provider. The existing recommender systems are mostly based on user data collected at servers, so user data are dispersed over several servers. Therefore, web servers that lack sufficient user behavior data cannot easily infer user preferences. Also, if the user visits the server infrequently, it may be hard to reflect the dynamically changing user's interest. This paper proposes a novel personalization system analyzing the user preference based on web documents that are accessed by the user on a user device. The system also identifies non-content blocks appearing repeatedly in the dynamically generated web documents, and adds weight to the keywords extracted from the hyperlink sentence selected by the user. Therefore, the system establishes at an early stage recommendation strategies for the web server that has little user data. Also, user profiles are generated rapidly and more accurately by identifying the information blocks. In order to evaluate the proposed system, this study collected web data and purchase history from users who have current purchase activity. Then, we computed the similarity between purchase data and the user profile. We confirm the accuracy of the generated user profile since the web page containing the purchased item has higher correlation than other item pages.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.12 no.4
• /
• pp.139-147
• /
• 2004

We have isolated two bacterial strains, FM-02 and AL-02, which produced EPS from forest soil for the restoration of forest fire by promoting soil aggregation. FM-02 was found to be Gram negative rod and belong to Beta Proteobacterium sp. through 16s-rDNA sequence analysis, and AL-02 was Gram positive rod and showed 81% of similarity to Zoogloea sp. through the analysis of 16s-rDNA sequence. FM-02 and AL-02 produced about 1.8g and 8.3g of EPS, respectively, per 1L of culture as dry weight. Flocculation activity (FA) was also measured in two strains. FM-02 showed 2.31 FA against active carbon, and AL-02 showed 6.21 FA against kaolin clay. From these results, we expect that AL-02 strain will be applied as a good biological material for the reduction of forest soil erosion by wild and rain after fire through promoting coagulation of soil particles.