• 한국잠사곤충학회지
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• 제42권2호
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• pp.99-103
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• 2000

This study was carried out to investigate incubating characteristics, LTSEM observation, nature of a disease of infected silkworms(bombyx mori), LD$\_$50/, optimum infective condition for mass production and infection percentage(%) on conservation periods. On the V8 media, the colony was 0.5∼2.0cm/8 days in diameter and white or slighty colored with a white fluffy to powdery appearance. The conidia was subglobos in shape, zig-zag appearance, 1-celled, hyaline and 3.2$\times$2.4 ㎛ in size on the average. The conidiophore was irregular grouped, hyaline, rounded or flask-shaped. The LD$\_$50/ values of the 2nd and 4th silkworms were each other 6.6142(Log) in natural temperature and humidity (25$\^{C}$, 65%). On optimum infective condition for mass production, all of preservation time(hr.) postinoculation in 1.0$\times$10$\^$8/ conidia/㎖ was over 97% and only 20 hr in 1.0$\times$10$\^$7/ condia/㎖ was over 90%.

• 한국균학회지
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• 제51권4호
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• pp.373-381
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• 2023

This study aimed to isolate and characterize wild yeast strains from the vineyard soil in Korea. Twenty yeast strains were isolated from vineyard soil in Gimpo-si, Gyeonggi-do, Korea, where Vitis labrusca cv. Campbell Early is grown. Eighteen strains were previously recorded in Korea. The remaining two, Cyberlindnera mrakii VG-21-10C and Starmerella bacillaris GR9 were not previously recorded in Korea. The mycological characteristics of VG-21-10C and GR9 were investigated. Both were oval-shaped, convex, and smooth. However, differences were evident in colony color and carbon assimilation activities. Strain VG-21-10C is white-colored and assimilates glucose, glycerol, D-xylose, D-cellobiose, D-saccharose, and D-raffinose as carbon sources. Strain GR9 is cream-colored and assimilates glucose, D-saccharose, and D-raffinose as carbon sources.

• Tuberculosis and Respiratory Diseases
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• 제58권4호
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• pp.385-391
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• 2005

연구배경 : 최근 국내에서도 NTM 분리율 및 감염 빈도가 증가하고 있는 추세이다. 본 연구는 국내 한 삼차의료기관에서 1년 동안 항산균 검사가 의뢰된 호흡기 검체에서 NTM의 배양양상 및 분리비율을 살펴보고 그 임상적 의의에 대해 알아보고자 하였다. 방 법 : 2002년 1년간 서울아산병원에서 미생물검사실로 항산균 검사가 의뢰된 호흡기 검체를 대상으로 도말, 배양 및 동정 결과를 확인하고 그 임상적 의의를 분석하였다. 결 과 : 총 9,821명의 환자에서 26,820건의 항산균검사가 시행되었다. 결핵균이 동정 된 건수와 환자수의 비율은 각각 5.7%, 6.3%였고, 비결핵항산균은 각각 2.2%, 2.8% 이었다. 도말양성, 배양양성 중 결핵균 및 NTM의 비율은 각각 87.8%, 12.2%이었다. NTM 중 오염의 가능성이 높은 암색소성-저집락군은 31.8%(186/584 균주)에서 분리되었다. 암색소성-저집락군을 제외한 NTM 중 MAC, M. fortuitum complex의 분리비율이 42.1%(138/328), 19.5%(64/328)로 가장 높았다. 암색소성-저집락군을 제외한 NTM이 분리된 275명 중 미국 및 영국 흉부학회 진단기준을 만족하는 NTM 폐질환은 각각 8.4%(23명), 17.8%(49명)이었다. 결 론 : 국내 한 대학병원에서의 항산균 검사 결과 NTM의 분리 비율이 높고 일부는 NTM 폐질환의 원인이어서 항산균 도말 및 배양 양성의 경우 국내에서도 반드시 NTM의 가능성을 고려하여야 하겠다.

• 미생물학회지
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• 제19권3호
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• pp.128-136
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• 1981

In order to investigate early identification of species of the wood-decaying fungi in the the mycelial stage, the authors isolated of 41 species, 28 genus, 9 family at 8 locations in Korea and cultivated these isolates on the various kinds of solid media. After investigating such cultural characteristics as oxidase reactions with tannic and gallic acid, various morphological features of colony and growth grade, appeared on the various media, the authors obtained the following results : 1. The oxidase reactions with tannic and gallic acid in the PDTA, DTA, PDGA and DGA media are available for identificantion of the wood-decaying fungi. 2. The oxidase reactions with guaiacol, pyrogallol and hydroquinone in the PDGUA, PDPA and PDHA media are not so much available for identification of the wood-decaying fungi. 3. Morphological features of colonies such as mycelium color, floccose, floccose-powdery, mycelloid, powdery-mycelloid, velvet, radiate, contoured, rosulate and growth grade on the PDA, PSA and PXA media are useful for identification of wood-decaying fungi. 4. It is believed that early identification in species level of wood-decaying fungi using cultural characteristics in the mycelial stage is possible. 5. The key for the identification of 41 species of wood-decaying fungi is proposed by the cultural characteristics using several solid media.

• Journal of Dairy Science and Biotechnology
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• 제41권3호
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• pp.138-148
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• 2023

In this study, Lactococcus lactis subsp. hordniae JNU533 (JNU533) was isolated from Swiss-type cheese, and the bacteriocin produced by this strain was characterized. The spot-on-lawn assay was used to determine the antimicrobial spectrum and characteristics of the JNU533-derived bacteriocin. Results confirmed that the JNU533-derived bacteriocin inhibited the growth of lactic acid bacteria. The size of the bacteriocin was approximately 4.9 kDa, and it was heat- and pH-stable under various temperature and pH conditions. Furthermore, the possibility of using JNU533 as a starter culture in the manufacturing of fermented dairy products was assessed. A single colony of JNU533 was inoculated into 10% skim milk containing 0.5% glucose to investigate its characteristics in milk culture. The decrease in the pH was similar to that elicited by Lactobacillus delbrueckii subsp. bulgaricus. Furthermore, the results confirmed that JNU533 inhibited the growth of various bacteria and could be used as a milk fermentation starter. This study highlights the characteristics of the bacteriocin produced by JNU533 and the growth features of this strain in a skim milk medium.

• Mycobiology
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• 제33권1호
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• pp.1-6
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• 2005

Morphological characteristics of hyphal interaction between Grifola umbellata (Pers. Ex Fr.) Pilat and its companion fungus which related to sclerotia formation from hyphae were investigated by external observations, light microscopy and transmission electron microscopy (TEM). External observations showed that a dense antagonism line was formed by both G. umbellata and companion fungus after their hyphae contacted each other in dual culture. Many hyphal strands emerged on the colony of G. umbellata and differentiated to sclerotia from where hyphal strands crossed. Light microscope observations revealed the process of antagonism line formation. Mature antagonism with structural differentiation, was composed of three main layers: the rind, the rind underlayer and the hypha layer. TEM observations showed that after colonies hyphal contact, a series of reactions always occurred in both G. umbellata and companion fungus. Cells in the center of antagonism line were dead. Cells of G. umbellata adjacent to the antagonism line were usually large and hollow, with unilateral thickened wall, whereas those of companion fungus were empty, with thin or thick wall. Both hyphal interaction at the antagonism line may be one of the main reasons for sclerotia of G. umbellata differentiation from hypha.

• The Plant Pathology Journal
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• 제21권3호
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• pp.221-228
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• 2005

A total of 179 isolates of Trichoderma spp. were collected from oyster mushroom substrates in Korea. On the basis of morphological and cultural characteristics, Trichoderma isolates were divided into seven groups, namely T. atroviride, T. citrinoviride, T. harzianum, T. longibrachiatum, T. virens, and two unidentified species, referred to as Trichoderma sp. 1 and 2. The predominant species was Trichoderma sp. 2 (n=86) followed by Trichoderma sp. 1 (n=52). Trichoderma sp. 1 and 2 were morphologically distinct not only from the other species of Trichoderma reported but also from each other in the characteristics such as mycelial growth rate, colony appearance, shape of conidia and conidiophores and branching pattern of phialides, although branching pattern of phialides of Trichoderma sp. 1 was similar to that of T. harzianum. In virulence test, the degree for compost colonization of Trichoderma sp. 2 was significantly greater than that of the other Trichoderma species. Trichoderma sp. 2 was found to be the main cause of green mold disease in oyster mushroom production. More work including molecular characterization is needed to confirm the species of Trichoderma sp. 1 and 2.

• Mycobiology
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• 제35권4호
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• pp.180-185
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• 2007

Grape fruits with blue mold symptoms were collected from house storages in different locations in Korea and were investigated for their association with Penicillium species. A total of 12 isolates of Penicillium were isolated from the collected fruits. Based on morphological and cultural characteristics and ${\beta}-tublin$ gene sequence data analysis, they were identified as P. bialowiezense, P. citrinum, P. echinulatum, P. expansum, P. solitum and unidentified Penicillium species. P. solitum was the predominant followed by P. expansum. P. bialowiezense and P. echinulatum were newly recorded in Korea. ${\beta}-Tubulin$ gene sequences could be used to distinguish each species of Penicillium and the molecular groups were correlated well with the morphological species. The unidentified species was supposed to be a new species, not previously reported in literature.

• 한국의류산업학회지
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• 제7권1호
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• pp.70-74
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• 2005

This study was aimed to isolation and identification of attached bacteria on the clothes excavated from Deajeon area dating on the 16th century. From the observation with colony shape, 17 bacterial strains were isolated, and then 7 bacterial strains were identified with morphological and biochemical characteristics. Streptococcus sp., Alcaligenes faecalis, Gemella sp., Acinetobacter sp., Pseudomonas vesicularis, Aeromonas sain. salmonicida, Moraxella spp. In observation of the bacterial strains by the sort of textile, more bacterial strains were found in silk, cotton, and cotton batt than in ramie and hemp. It is suggest that hemp has antibacterial characteristics due to the presence of lignin. In the comparison washed samples with unwashed ones, there were more kinds of bacterial strains in washed samples. In the cellulase activity tests, all isolated bacteria had low level cellulase activity.

• Mycobiology
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• 제34권2호
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• pp.83-91
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• 2006

Characteristic growth patterns of Cordyceps militaris isolates on various media, under varying light conditions and at varying incubation periods were examined. Light was found to be the most critical single factor in determining the density, texture, and pigmentation of the mycelial culture of the fungus. However, under the light condition, the degree of pigmentation and mycelial density were found to be affected by the incubation period and type of medium. Irrespective of the variations in medium type or incubation period, there was no pigmentation of the mycelium under dark condition. Radial growth of the mycelium was faster under dark incubation rather than under light incubation. Abundant mycelial density and darkest pigmentation of C. militaris isolates were produced in nutritionally rich media like SDAY, SMAY and CZYA, suggesting that these media may fulfill all the requirements for vegetative growth of the fungus. Growth characteristics of C. militaris isolates could be easily observed by the simple agar culture method, which would be useful to characterize the phenotypic characteristics of large number of pure cultures of the fungus under given conditions of growth factors such as medium, light and temperature.