• Microbiology and Biotechnology Letters
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• v.34 no.2
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• pp.101-108
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• 2006

YNB54 strain which shows inhibitory activities specific to the plant pathogenic Phytophthora sp. on potato dextrose agar medium was screened among lots of strains isolated from Korean soils. To identify taxonomy of the Phytophthora specific antagonistic bacteria YNB54, 165 rDNA sequence, MIDI fatty acid composition, DNA-DNA hybridization, GC content, and commercial multitest systems such as API 20E and Biolog GN were performed. Results of commercial kits including lots of biochemical and physiological reactions showed that this strain was closely related to taxa including Enterobacter cloacae and Enterobacter cancerogenus species than other genera(Citerobacter Klebsiella, Leclercia). Also, analysis of its MIDI, G+C contents, and DNA-DNA hybridization suggests that this strain was more similiar to the Genus Enterobacter than other genera (Citerobacter Klebsiella, Leclercia). This strain was potentially identified as Enterobacter sp. by these results. But our 16S ribosomal DNA sequences (rDNA) analysis confirmed that it was more closely related to the cluster of Citerobacter freundii ATCC 29935 than any other Enterobacter species. In the absence of defined phylogenetic critia for delineating genera, the results observed with Citrobacter and Enterobacter species suggest that further studies are needed to clarify their relationships. This investigation demonstrates that YNB54 strain is genetically diverse and potentially more taxonomically complex than hitherto realized. Further study is necessary to confirm their taxonomic positions.

• Journal of Life Science
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• v.33 no.4
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• pp.325-333
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• 2023

This study compared and analyzed the microbial composition and physicochemical characteristics of kimchi (gimjang kimchi) and mukeunji (aged kimchi). Commercial kimchi and mukeunji products were purchased through an online market. After an analysis of physicochemical characteristics, the pH of the mukeunji samples was found to be lower and the acidity higher than in the kimchi samples. There was no significant difference in salinity between kimchi and mukeunji, but the sugar content was higher in the kimchi samples. The phylogenetic diversity index, which incorporates phylogenetic difference between species, was significantly higher in mukeunji than in the kimchi. The most dominant order in both groups was Lactobacillales, but several lactic acid bacteria, such as the Pediococcus and Lactobacillus species, which may be more acid tolerant or more competitive, are relatively predominant in mukeunji. Beta set-significance analysis based on two different distance metric results revealed that microbial distributions of population were different at the statistical confidence level (p<0.001). We investigated the effect of respective species on total microbial community using the LEfSe (linear discriminant analysis effect size) mechanism. According to the results of LEfSe testing, a relatively higher abundance of Weissella kandleri in kimchi and a higher abundance of Pediococcus inopinatus in mukeunji have the greatest influence on the differences in microbial structure between the two groups.

• Animal cells and systems
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• v.13 no.3
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• pp.351-356
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• 2009

Ciliates are undoubtedly one of the most diverse protozoans that play a significant role in ecology. However, molecular examination, based on comparing the DNA sequences, has been done on a limited number of the species. Because most ciliates are uncultivable and their population sizes are often too small, it is usually difficult to obtain sufficient genomic DNA required for PCR based experiments. In the present study, we evaluated the effectiveness of four commercial DNA extraction procedures that extract high quality genomic DNA from a single ciliate cell. It was discovered that RED Extract-N-$Amp^{TM}$ PCR kit is the best method for removing PCR-inhibiting substances and minimizing DNA loss during purification. This method can also amplify more than 25 reactions of PCR. In addition, this technique was applied to single cells of 19 species belonged to 7 orders under 5 classes that isolated from mixed natural populations. Their small subunit ribosomal DNA (SSU rDNA) was successfully amplified. In summary, we developed a simple technique for the high-yield extraction of purified DNA from a single ciliate cell that may be more useful for rare ciliates, such as tiny and uncultivable marine microbes.

• Plant Biotechnology Reports
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• v.2 no.3
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• pp.213-218
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• 2008

Swertia chirata is an endangered gentian species that prefers to grow at higher altitudes. This ethnomedicinal herb is known primarily for its bitter taste caused by the presence of important phytochemicals that are directly associated with human health benefits. Due to a continuous loss of habitat and inherent problems of seed viability and seed germination, alternative strategies for propagation and conservation are urgently required to prevent the possible extinction of this species. We have formulated a reproducible protocol for the rapid propagation and conservation of this plant using leaves taken from in vitro shoot cultures. Direct induction of more than seven shoot buds per explant was achieved for the first time when the explants were placed on MS medium supplemented with $2.22{\mu}M$ N-6-benzyladenine, $11.6{\mu}M$ kinetin, and $0.5{\mu}M$ ${\alpha}-naphthalene$ acetic acid. Direct organogenesis was noted exclusively from the adaxial surface of the basal segments of leaves. Leaves closer to the apical meristem were more responsive than those farther away from the meristem. Plants raised through direct organogenesis were evaluated for their clonal fidelity by chromosomal analysis and DNA fingerprinting. Complete plants were successfully transferred to the field condition and produced viable seeds. Given the enormous potential of this age-old medicinal plant in terms of potential health-benefitting drugs, this protocol can be used for commercial propagation purposes and to initiate future genetic improvement studies.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.48 no.3
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• pp.44-50
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• 2016

As a raw material for pulp and paper industry, Moso bamboo, Timber bamboo and Henon bamboo pulps were prepared by soda or soda-anthraquinone(Soda-AQ) pulping process. Soda-AQ pulp yields was higher in Henon bamboo (43.2%) than in Moso bamboo or Timber bamboo (32.7-39.2%), but quite lower than hardwood species. In Kappa number comparison, Henon bamboo pulp showed lower (16.6) with 50 min cooking to $170^{\circ}C$ than that of Moso bamboo (22.8) and Timber bamboo (18.9) with 90 min cooking to $170^{\circ}C$. Fiber length of Timber bamboo soda pulp had higher (1.46 mm) than that of Moso bamboo or Henon bamboo (1.18-1.36 mm). All three bamboo pulps showed longer average fiber length than commercial hardwood pulp. With higher pulp yield and lower Kappa number, Henon bamboo is better raw material for pulp than Moso bamboo and Timber bamboo.

• The Plant Pathology Journal
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• v.28 no.3
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• pp.311-316
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• 2012

Fusarium root disease can be a serious problem in forest and conservation nurseries in the western United States. Fusarium inoculum is commonly found in most container and bareroot nurseries on healthy and diseased seedlings, in nursery soils, and on conifer seeds. Fusarium spp. within the F. oxysporum species complex have been recognized as pathogens for more than a century, but attempts to distinguish virulence by correlating morphological characteristics with results of pathogenicity tests were unsuccessful. Recent molecular characterization and pathogenicity tests, however, revealed that selected isolates of F. oxysporum are benign on Douglas-fir (Pseudotsuga menziesii) seedlings. Other morphologically indistinguishable isolates, which can be virulent, were identified as F. commune, a recently described species. In a replicated greenhouse study, inoculating Douglas-fir seedlings with one isolate of F. oxysporum prevented expression of disease caused by a virulent isolate of F. commune. Moreover, seedling survival and growth was unaffected by the presence of the F. oxysporum isolate, and this isolate yielded better biological control than a commercial formulation of Bacillus subtilis. These results demonstrate that an isolate of nonpathogenic F. oxysporum can effectively reduce Fusarium root disease of Douglas-fir caused by F. commune under nursery settings, and this biological control approach has potential for further development.

• Journal of the Korea Furniture Society
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• v.21 no.2
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• pp.188-195
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• 2010

This study has been focused on the evaluation of domestic softwood timbers to replace imported timbers for woodcrafts and furniture-making. Figures on radial and tangential sections were observed with naked eyes. As the result of study on the figures appeared on the wood surface of 6 species of trees, flat grain and edge grain were clearly found from Taxus cuspidata. Juniperus chinensis and Ginkgo biloba had wavy grain figure and pigment figure, and blister figure was found in Pinus densiflora, Larix kaempferi showed pitch streak and irregular figures on its tangential section due to growth abnormalities. Wavy grain figure appeared weakly on near knot of Pinus koraiensis. The characteristic figures shown from each species of trees are expected to be used for crafts, sculptures, furniture, and interior decoration. They are also considered to have great potential to substitute imported timber sufficiently, which are currently used a lot for wood crafts and furniture-making.

• Microbiology and Biotechnology Letters
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• v.25 no.4
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• pp.391-395
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• 1997

It was proved that both ethanol extracts from Mori Folium from Kangwon do and silk worm had higher inhibition acitivity on $\alpha$-glucohydrolase than the water extracts. In adding above 8.5 (mg/L) of silkworm extracts, the inhibition rate on $\alpha$-1,4 glucosidase was saturated while the inhibition rate was continuously increased in adding the extracts from Moli Folium. It was also found that the diethyl ether fraction showed much better inhibition activity than water fraction from ethanol extracts, yielding ca. 85% of inhibition rate for the extract of Moli Folium, compared to 91% for a commercially available hypoglycemic drug, Chloropropamide. In separating the diethyl ether fractions by Consecutive Sephadex gel filtration and Thin layer chromatography, three and four active spots were obtained from Moli Folium and silkworm, respectively. It is interesting that the similar Rf spots from both species among several spots in TLC have the highest inhibition acitivity on a target enzyme, which can imply that the active substances from both species are same or similar molecular weight and structure. Glucose-lowering activities of both speciese were also examined in vivo, showing that the fraction from Moli Folium had better activity than that from silkworm, and its activity was similar to that of a commercial drug.

• Journal of Microbiology and Biotechnology
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• v.19 no.2
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• pp.136-139
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• 2009

Avermectin and its analogs are major commercial antiparasitic agents in the fields of animal health, agriculture, and human infections. Previously, comparative transcriptome analysis between the low-producer S. avermitilis ATCC31267 and the high-producer S. avermitilis ATCC31780 using a S. avermitilis whole genome chip revealed that 50 genes were overexpressed at least two-fold higher in S. avermitilis ATCC31780. To verify the biological significance of some of the transcriptomics-guided targets, five putative regulatory genes were individually cloned under the strong-and-constitutive promoter of the Streptomyces expression vector pSE34, followed by the transformation into the low-producer S. avermitilis ATCC31267. Among the putative genes tested, three regulatory genes including SAV213, SAV3818, and SAV4023 exhibited stimulatory effects on avermectin production in S. avermitilis ATCC31267. Moreover, overexpression of SAV3818 also stimulated actinorhodin production in both S. coelicolor M145 and S. lividans TK21, implying that the SAV3818, a putative TetR-family transcriptional regulator, could be a global upregulator acting in antibiotic production in Streptomyces species.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.620-623
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• 2004

In this study, the discharge characteristic of FTS (Facing Targets Sputtering) apparatus was investigated using metal target paramagnetic and ceramic targets such as Zn, Al, $ZnO:Al(Al_2O_3)$, ITO. Threshold voltage and stable stage of discharge show different with target species. Compare with commercial sputtering apparatus, the FTS apparatus is a high-speed sputter method that promotes ionization of sputter gas by screw and reciprocate moving high-speed ${\gamma}$electrons which arrays two targets facing each other, inserts plasma arresting magnetic field to the parallel direction of the center axis of both targets, discharged from targets and accelerated at the cathode falling area. Especially, we notice that the FTS method using ceramic target has stable discharge characteristic even by DC power source.