• Journal of Microbiology and Biotechnology
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• 제16권10호
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• pp.1591-1596
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• 2006

Acaricidal effects of materials derived from Caesalpinia sappan heartwoods against Dermatophagoides farinae and D. pteronyssinus were assessed and compared with those evidenced by commercial benzyl benzoate and DEET. The observed responses varied according to dosage and mite species. The $LD_{50}$ values of the methanol extracts derived from C. sappan heartwoods were 6.13 and $5.44{\mu}g/cm^3$ against D. farinae and D. pteronyssinus, respectively. Furthermore, the ethyl acetate fraction derived from the methanol extract was approximately 8.71 more toxic than DEET against D. farinae, and 4.73 times more toxic against D. pteronyssinus. The biologically active constituent from the ethyl acetate fraction of C. sappan heartwood extract was purified via silica gel chromatography and high-performance liquid chromatography. The structure of the acaricidal component was analyzed by $GC-MS,\;^1H-NMR,\;^{13}C-NMR,\;^1H-^{13}C\;COSY-NMR$, and DEPT-NMR spectroscopy, and identified as juglone (5-hydroxy-l,4-naphthoquinone). Based on the $LD_{50}$ values of juglone and its derivatives, the most toxic compound against D. farinae was juglone ($0.076{\mu}g/cm^3$), followed by benzyl benzoate ($9.143{\mu}g/cm^3$) and 2methyl-l,4-naphthoquinone ($40.0{\mu}g/cm^3$). These results indicate that the acaricidal activity of C. sappan heartwoods is likely to be the result of the effects of juglone. Additionally, juglone treatment was shown to effect a change in the color of the cuticles of house dust mites, from colorless-transparent to dark brownish-black. Accordingly, as a naturally occurring acaricidal agent, C. sappan heartwood-derived juglone should prove to be quite 'useful as a potential control agent, lead compound, and house dust mite indicator.

• 한국농림기상학회지
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• 제8권2호
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• pp.77-85
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• 2006

Entomopathogenic nematodes (EPNs) have been used as biological control agents for control of various agro-forest insect pests, and are especially effective against soil-dwelling insect pests. Effect of soil moisture on pathogenicity of commercial EPNs for white grub control was evaluated in laboratory, pots, and golf courses. Pathogenicity of EPNs in sand column was variable depending on depth, soil moisture, and EPN species or strain. All tested EPNs (Heterorhabditis sp. GSNUH1, Heterorhabditis sp. GSNUH2, Steinernema carpocapsae GSN1, and S. longicaudum Nonsan strain) showed similar pathogenicity against the bait insect, great wax moth (Galleria mellonella) larva at 2 cm deep at a given soil moisture. However, pathogenicity of the Heterorhabditis sp. GSNUH1 strain was decreased with increasing soil moisture. Pathogenicity of S. carpocapsae GSN1 strain was the lowest in 3% soil moisture (v/w) at 7 cm depth. However, there was no difference in pathogenicity between Heterorhabditis sp. GSNUH2 and S. longicaudum Nonsan strain. Although pathogenicity of Heterorhabditis sp. KCTC 0991BP strain showed no difference against the 2nd instar of Exomala orientalis, that of the S. carpocapsae GSN1 strain was decreased in the laboratory depending on soil moisture. Highly pathogenic strain EPN, Heterorhabditis sp. KCTC 0991BP strain, showed higher pathogenicity at 100 mm irrigation than non-irrigation or 10 mm irrigation. However, poor pathogenic strain EPN, S. carpocapsae GSN1 strain, was not different in pathogenicity from the 2nd instar of Exomala orientalis in creeping bentgrass (Agrostis palustris) depending on irrigation amount in the pot. Pathogenicity of EPNs in field experiment at the tee of Ulsan golf club showed a similar trend to that in the pot experiment.

• 한국수산과학회지
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• 제35권6호
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• pp.696-701
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• 2002

Cellulase를 이용하여 키토산 올리고당을 제조하기 위한 최적조건을 반웅표면 분석법을 이용하여 설정하였다 키토산 분해능과 산업적 활용의 측면에서 유리한 Pen. funiculosum 유래의 cello-lase를 예비 실험을 통해 결정하였다. 이 효소의 적정 반응 조건에서 경시적 키토산 분해율을 측정한 결과, 반응 10시간까지는 대수적 증가를 보였으나, 10시간 이후로는 완만한 분해율을 나타내었다. 중심합성계획에 의해 총 26개의 실험을 행한뒤 반응표면분석법으로 설정한 키토산 분해 최적 조건은 기질 농도 $0.5\%$에 대해 효소 농도 143(U), 반응 온도 $49^{\circ}$, 반응 시간 13.2hr및 pH는 3.8이었다. 본 연구에서 설정된 최적의 조건에서 얻어진 키토산 분해물은 dimer와 trimer가 주된 올리고당이었고, 소량의 tetramer와 hexamer 그리고 monomer 등의 총 8종 정도의 올리고당이 검출되었다.

• The Plant Pathology Journal
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• 제31권4호
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• pp.441-445
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• 2015

Carrot (Dacus carota var. sativus) is one of the top-ten most economically important vegetable crops produced worldwide, and the root-knot nematodes, Meloidogyne spp., are one of the most important pests in the carrot. In Korea, M. hapla and M. incognita are presumed to be the major root-knot nematodes distributing mostly in open carrot fields and greenhouses, respectively. In our study, currently-developed and commercial carrot cultivars and the parental lines were examined for their pathological responses to M. incognita and M. hapla 7 weeks after inoculation with about 1,000 second-stage juveniles (J2) of the nematodes. All the carrot cultivars and lines showed susceptible responses to both nematodes with the gall index (GI) of 2.4-4.4, which were always higher on the carrot plants infected with M. incognita than M. hapla. Gall sizes were remarkably larger with more serious reduction of the root growths in the plants infected with M. incognita than M. hapla, suggesting the carrot lines examined in our study were more susceptible to the former than the latter. In the infection sites of the root tissues, giant cells were more extensively formed, occupying larger stellar regions with the prominent destruction of adjacent xylem vessels by M. incognita than M. hapla. All of these results suggest M. incognita affect more seriously on the carrot plants that are grown in greenhouses, compared to M. hapla that has a major distribution in open carrot fields, which would be used for determining cropping systems based on target nematode species, their damage and pathological characteristics.

• The Plant Pathology Journal
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• 제36권6호
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• pp.579-590
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• 2020

Botrytis cinerea, which causes gray mold disease in more than 200 plant species, is an economically important pathogen that is mainly controlled by synthetic fungicides. Synergistic fungicide mixtures can help reduce fungicide residues in the environment and mitigate the development of fungicide-resistant strains. In this study, we screened microbial culture extracts on Botrytis cinerea to identify an antifungal synergist for tebuconazole. Among the 4,006 microbial extracts screened in this study, the culture extract from Schizophyllum commune displayed the most enhanced activity with a sub-lethal dosage of tebuconazole, and the active ingredient was identified as schizostatin. In combination with 5 ㎍/ml tebuconazole, schizostatin (1 ㎍/ml) showed disease control efficacy against gray mold on tomato leaf similar to that achieved with 20 ㎍/ml tebuconazole treatment alone. Interestingly, schizostatin showed demethylation inhibitor (DMI)-specific synergistic interactions in the crossed-paper strip assay using commercial fungicides. In a checkerboard assay with schizostatin and DMIs, the fractional inhibitory concentration values were 0.0938-0.375. To assess the molecular mechanisms underlying this synergism, the transcription levels of the ergosterol biosynthetic genes were observed in response to DMIs, schizostatin, and their mixtures. Treatment with DMIs increased the erg11 (the target gene of DMI fungicides) expression level 15.4-56.6-fold. However, treatment with a mixture of schizostatin and DMIs evidently reverted erg11 transcription levels to the pre-DMI treatment levels. These results show the potential of schizostatin as a natural antifungal synergist that can reduce the dose of DMIs applied in the field without compromising the disease control efficacy of the fungicides.

• International Journal of Industrial Entomology and Biomaterials
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• 제21권1호
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• pp.133-137
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• 2010

The perilla leaf pyralid moth, Pyrausta panopealis Walker (Lepidoptera: Pyralidae), is a serious pest damaging to leaf perilla. In order to establish the life parameters of P. panopealis for eventual purpose of control, the developmental span of each stage was investigated under five temperature regimes ($20^{\circ}C{\sim}30^{\circ}C$). The larval period of P. panopealis was longest as 26.8 days at $20^{\circ}C$ and shortened as temperature goes up to $30^{\circ}C$ as 11.3 days. Survivorship of the larval P. panopealis was the highest at $27.5^{\circ}C$ as 82.5%, whereas that of other temperatures ranged from 40% ($20^{\circ}C$) to 60.0% ($30^{\circ}C$), indicating that the P. panopealis appears to favor somewhat higher temperature. In addition to larval period, the duration of egg, prepupal, and pupal period also were shortened sharply as temperature goes up, whereas the duration of adult stage shortened a maximum of only two days as temperature goes up. After the perilla leaf pyralid moths were successfully stabilized in indoor environment the larvicidal efficacy of ten on-the-market environmentfriendly agricultural materials (EFAMs) that were previously selected from the result of other moth species was tested. Seven of the ten tested showed more than 90% of mortality within 12 hrs and reached nearly up to 100% within 24 hrs, but the remaining three showed less than ~70%.

• 대한핵의학회지
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• 제37권1호
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• pp.43-52
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• 2003

Microarray technology allows the simultaneous analysis of gene expression patterns of thousands of genes, in a systematic fashion, under a similar set of experimental conditions, thus making the data highly comparable. In some cases arrays are used simply as a primary screen loading to downstream molecular characterization of individual gene candidates. In other cases, the goal of expression profiling is to begin to identify complex regulatory networks underlying developmental processes and disease states. Microarrays were originally used with ceil lines or other simple model systems. More recently, microarrays have been used in the analysis of more complex biological tissues including neural systems and the brain. The application of cDNA arrays in neuropsychiatry has lagged behind other fields for a number of reasons. These include a requirement for a large amount of input probe RNA In fluorescent-glass based array systems and the cellular complexity introduced by multicellular brain and neural tissues. An additional factor that impacts the general use of microarrays in neuropsychiatry is the lack of availability of sequenced clone sets from model systems. While human cDNA clones have been widely available, high qualify rat, mouse, and drosophilae, among others are just becoming widely available. A final factor in the application of cDNA microarrays in neuropsychiatry is cost of commercial arrays. As academic microarray facilitates become more commonplace custom made arrays will become more widely available at a lower cost allowing more widespread applications. in summary, microarray technology is rapidly having an impact on many areas of biomedical research. Radioisotope-nylon based microarrays offer alternatives that may in some cases be more sensitive, flexible, inexpensive, and universal as compared to other array formats, such as fluorescent-glass arrays. In some situations of limited RNA or exotic species, radioactive membrane microarrays may be the most practical experimental approach in studying psychiatric and neurodegenerative disorders, and other complex questions in the brain.

• 한국축산식품학회지
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• 제27권4호
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• pp.496-500
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• 2007

The lactase activities of nine species of lactic acid bacteria were compared using the chromogenic substrate, $o-nitrophenyl-{\beta}-D-galactopyranoside$. Streptococcus thermophilus KACC 91147 had the highest lactase activity among a total of thirty strains of Lactobacillus and S. thermophilus tested, including commercial strains. S. thermophilus KACC 91147 released $0.30{\pm}0.12\;mg/mL$ of galactose in treated milk A ($10^7\;CFU/mL$) and $6.49{\pm}0.38\;mg/mL$ in treated milk B ($10^9\;CFU/mL$ milk) over 2 hours. In milk tolerance tests, the blood glucose level (BGL) of 6 volunteers (2 males and 4 females) clinically diagnosed as lactose intolerant increased 3.0 mg/dl after drinking milk A, but a significant (p<0.05) additional increase of $11.2{\pm}4.18\;mg/dl$ was found after drinking milk B. This result suggests that the addition of S. thermophilus KACC 91147 cells into milk aids the digestion of lactose in milk and ameliorates the symptoms of lactose-intolerant individuals due to the activity of lactase from the lactic streptococci.

• 수산해양기술연구
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• 제54권4호
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• pp.279-286
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• 2018

The objective of this study was to quantitatively evaluate the influence of the netting hanging ratio on fishing performance of gillnet. A total of six tests was carried out using three kinds of gillnets with different horizontal hanging ratios (0.3, 0.5 and 0.7) on the basis commercial gillnet of mesh size of 60 mm used in Yeosu Dolsan. As a result of the test fishing operation, catches of the net with hanging ratio 0.3 and the shortest float length was 1.34 times larger than the net with hanging ratio 0.7. The caught species in experimental testes was lager in the net with hanging ratio 0.3 than the net with hanging ratio 0.7. The catch rate per unit area (CPUE) is on the silver croaker with the largest catches in tests as follows. The net with hanging ratio 0.3 net was $89.45g/m^2$, hanging ratio 0.5 net was $41.63g/m^2$, and hanging ratio 0.7 net was $24.50g/m^2$. The net with hanging ratio 0.3 (float line length of 45 m) exhibited the largest CPUE value.

• 식물병연구
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• 제25권2호
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• pp.94-97
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• 2019

육묘장에서 파프리카 유묘의 줄기와 뿌리가 갈변하고 잎이 시드는 증상이 나타났으며 병든 어린 식물체는 묘판에 서있지 못하고 쓰러졌다. 파프리카 줄기와 뿌리의 감염 부위에서 곰팡이 단포자 균주를 획득하였다. 분리 균주를 carnation leaf agar에 배양하여 균학적 특성을 관찰한 결과, 대형분생포자는 약간 굽은 낫 모양으로 무색이고 $18-26{\times}3-5{\mu}m$이며 1-3개의 격벽이 있었다. 소형분생포자는 타원형으로 무색이고 $6-10{\times}2-4{\mu}m$이며 격벽이 없었다. 후벽포자는 원형으로 $7-12{\mu}m$이며 균사의 끝이나 중간에 형성되었다. 균주의 포자현탁액을 파프리카 종자와 유묘에 접종하여 병원성을 검정한 결과, 이 병원균은 종자의 발아를 억제하는 영향을 주었으며 유묘에는 잘록병 증상이 나타났다. 병든 파프리카 유묘에서 분리한 균주의 형태적 특성을 비롯하여 TEF 및 RPB1 유전자 염기서열 분석을 통해 원인균을 Fusarium oxysporum으로 동정하였으며, 파프리카 잘록병으로 명명하여 국내 처음으로 보고하고자 한다.