• Journal of Microbiology and Biotechnology
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• 제3권3호
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• pp.204-208
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• 1993

A fully automatic image analysis method was applied to obtain detailed data on morphological parameters of a glucoamylase fermentation broth with Aspergillus niger No. PFST-38. a mutant strain for glucoamylase hyperproducer. In the initial stage of fermentation. there was an increase in hyphal length. whereas at the end of the fermentation a decrease in hyphal length and increase in hyphal thickness were observed. The percentage of clumps declined with dilution and the influence of shear stress upon hyphal length was negligible. It was found that the slower the decrease in the main hyphal length and the number of tips with the fermentation time. the higher the glucoamylase production rate was recorded. The production rate of glucoamylase was closely related to the increase in the hyphal thickness.

• Biotechnology and Bioprocess Engineering:BBE
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• 제6권2호
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• pp.156-156
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• 2001

The objective of this study was to investigate the effects of nutrients and culture conditions on morphology during the seed culture of C. acremonium ATCC 20339 Morphological factors such as hyphal length number of tips number of arthrospores were observed to investigate the relationship between seed morphology and CPC production. During the time course of seed culture, hyphal length was shortened and the number of arthrospores increased rapidly On the other hand the number of tips deceased rapidly and this was closely related to the hyphal length Mixed nitrogen sources of 3% solybean meal and 1% cotton seed flour were determined as the proper organic nitrogen sources, in terms of the morphological factors in the seed culture. This fact was proven in batch culture for the production of Cephalosporin C. It was also found that a proper agitation speed enhanced the morphological differentiation of C. acremonium ATCC 20339, thus improving the production of Cephalosporin C.

• Journal of Microbiology and Biotechnology
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• 제27권5호
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• pp.947-955
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• 2017

Herbicidin A is a potent herbicide against dicotyledonous plants as well as an antibiotic against phytopathogens. In this study, fermentation parameters for herbicidin A production in submerged culture of Streptomyces scopuliridis M40 were investigated. The herbicidin A concentration varied with the C/N ratio. High C/N ratios (>4) resulted in a herbicidin A production of more than 900 mg/l, whereas maximally 600 mg/l was obtained at ratios between 1 and 3.5. In 5-L batch fermentation, there was a positive correlation between the oxygen uptake rate (OUR) and herbicidin A production. Once the OUR increased, the substrate consumption rate increased, leading to an increase in volumetric productivity. Mechanical shear force affected the hyphal morphology and OUR. When the medium value of hyphal size ranged from 150 to $180{\mu}m$, high volumetric production of herbicidin A was obtained with OUR values >137mg $O_2/l{\cdot}h$. The highest herbicidin A concentration of 956.6 mg/l was obtained at 500 rpm, and coincided with the highest relative abundance of hyphae of $100-200{\mu}m$ length and the highest OUR during cultivation. Based on a constant impeller tip speed, which affects hyphal morphology, herbicidin A production was successfully scaled up from a 5-L jar to a 500-L pilot vessel.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2001년도 추계학술발표대회
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• pp.382-385
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• 2001

The effect of agitation speed on the production of mycelial growth and exo-biopolymer in bioreaetor culture was investigated. The maximum production of mycelia and exo-biopolymer was obtained at 350 rpm, where the maximum concentrations of mycelial growth and exo-biopolymer were 62 g/L and 23 g/L, respectively. The effect of agitation speed on the hyphal length and the number of tips was examined. The hyphal length and the number of tips of Cordyceps sinensis 16 in bioreaetor culture at 350 rpm were increased up to 660 ${\mu}m$ and 14/ml, respectively.

• Journal of Microbiology and Biotechnology
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• 제23권7호
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• pp.1031-1040
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• 2013

Candida albicans is a dimorphic fungus that commensally colonizes human mucosal surfaces. The aim of this study was to assess the role of different C. albicans morphologies in inducing pattern recognition receptors (PRRs) and cytokines in macrophages. Macrophages may respond to pathogen-associated molecular patterns via TLR2 and TLR4 by expressing cytokines. The hyphal transition of C. albicans was induced by 20% serum (S), RPMI-1640 (R), or $39^{\circ}C$ culture (H). Macrophages were then challenged with either yeast (Y) or different hyphae cultures of C. albicans, followed by RT-PCR and FACS analysis of PRRs expression. In addition, macrophages were stimulated with either yeast or different hyphae cultures of C. albicans used by RT-PCR and Bio-Plex analysis of cytokines production. Macrophages expressed high levels of TLR4 and dectin-1 after stimulation with Y cells. In contrast, stimulation with H or R cells strongly increased the expression of TLR2 and dectin-2. Stimulation with Y cells significantly enhanced the expression of IL-$1{\beta}$ and weakly increased the expression of IL-6 and IL-12. Stimulation with hyphal cells (S, R, and H) strongly increased IL-10 expression, but weakly reduced IL-$1{\beta}$ expression. The phagocytosis activity and NO production of macrophages were decreased upon treatment with hyphal cells compared with yeast, and depended on the length of hyphae. In summary, the yeast and hyphae forms of C. albicans resulted in an induction of different PRRs, with accompanying differences in immune cell cytokine profiles.

• 농약과학회지
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• 제4권2호
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• pp.44-49
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• 2000

본 시험은 오이 양액재배시 배양액내 규산칼륨($K_{2}SiO_{3}$) 처리에 의한 생육단계별 규소의 흡수특성, 체내분표 병원균의 침입억제 효과를 검토하기 위하여 수행하였다. 잎에서의 규소 분포는 TEM, SEM 및 EDX-ray를 사용하여 4개(SEM, Ca, Si, K)의 구성원소를 각각 측정하였다. 흡수된 규소는 잎으로 이동하여 모용(毛茸, trichome, hair)을 둘러싸고 있는 기부 세포에 축적되었다. 모용에서의 규소는 고농도의 칼슘 및 칼륨과 혼재하여 분포하였고, 저농도 처리시에는 모용기부를 제외한 표피세포에서는 감지 할 수 없는 수준으로 분포하였다. 잎에서의 규소 축적은 처리 후 24시간에서 48시간 사이에 세포벽 주위에 가장 많이 축적되었고, 그 이후에도 다소 증가하는 경향이었다. 처리된 규소는 발아하고 있는 흰가루병 분생포자의 인접 조직의 세포벽과 병원균 흡기 주변에 다량 축적되어 물리적인 장벽으로 작용하였다. 고농도의 규산 처리된 잎 병반상의 발아관 길이는 낮은 농도의 처리구와 비교하여 현저히 짧았으며, 규산 처리농도와 부의 상관관계를 나타내었다. 배양액내 처리된 규산 농도는 오이가 생장함에 따라 감소하여 뿌리를 통하여 작물체내로 흡수되었으며, 저농도 처리구(0.85 mM이하)에서는 흡수되는 양이 현저히 적었다.

• The Plant Pathology Journal
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• 제33권4호
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• pp.362-369
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• 2017

White root rot disease, caused by the pathogen Rosellinia necatrix, is one of the world's most devastating plant fungal diseases and affects several commercially important species of fruit trees and crops. Recent global outbreaks of R. necatrix and advances in molecular techniques have both increased interest in this pathogen. However, the lack of information regarding the genomic structure and transcriptome of R. necatrix has been a barrier to the progress of functional genomic research and the control of this harmful pathogen. Here, we identified 10,616 novel full-length transcripts from the filamentous hyphal tissue of R. necatrix (KACC 40445 strain) using PacBio single-molecule sequencing technology. After annotation of the unigene sets, we selected 14 cell cycle-related genes, which are likely either positively or negatively involved in hyphal growth by cell cycle control. The expression of the selected genes was further compared between two strains that displayed different growth rates on nutritional media. Furthermore, we predicted pathogen-related effector genes and cell wall-degrading enzymes from the annotated gene sets. These results provide the most comprehensive transcriptomal resources for R. necatrix, and could facilitate functional genomics and further analyses of this important phytopathogen.

• 한국균학회소식:학술대회논문집
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• 한국균학회 2015년도 추계학술대회 및 정기총회
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• pp.14-14
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• 2015

Cellular aspects of sooty mold on walnut leaves were investigated by using light and electron microscopy. A black coating developed on the adaxial leaf surface of a walnut tree. No infestations were found on the abaxial leaf surface with peltate glandular trichomes. Light microscopy showed that fungal complexes from the leaf surface were composed of brown conidia and hyphae. Conidia, with longitudinal and transverse septa, were variable in length ranging from 10 to $30{\mu}m$, and commonly found in clusters, forming microsclerotia. Neither epidermal penetration nor hyphal entrance to host tissues was observed. Based on their morphological characteristics, the fungal complexes were assumed to be Capnodium species. An electron-dense melanized layer was present on the cell wall of multi-celled conidia. Concentric bodies in the fungal cytoplasm had an electron-translucent core surrounded by an electron-dense margin with a fibrillar sheath. Chloroplasts without starch granules in the palisade mesophyll cells of sooty leaves had electron-dense stromata and swollen plastoglobuli. These results suggest that the epiphytic growth of fungal complexes can be attributed to the melanized layer and concentric bodies against a water-deficient environment on the leaf surface. Ultrastructural characteristics of the sooty leaves indicate typical features of dark-adapted and non-photosynthetic shade leaves.

• 한국균학회소식:학술대회논문집
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• 한국균학회 2014년도 추계학술대회 및 정기총회
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• pp.48-48
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• 2014

Arbuscular Mycorrhizal Fungi(AMF) is widespread symbiont forming mutualistic relationship with plant root in terrestrial forest in ecosystem. They provide improved absorption of nutrient and water, and enhance the resistance against plant pathogen or polluted soil, therefore AM fungi are important for survival and maintaining of individual or community of plant. For last decade, many studies about the functional variation of AM fungi on host plant growth response were showed that different geographic isolates, even same species, have different effect on host plant. However, little was known about functional variation of AM fungal isolates originated single population, which provide important insight about intraspecific diversity of AMF and their role in forest ecosystem. In this study, four AM fungal isolates of Rhizophagus clarus were cultured in vitro using transformed carrot (Daucus carota) root and they showed the difference between isolates in ontogenic characteristics such as spore density and hyphal length. The plant growth response by mycorrhizas were measured also. After 20 weeks from inoculation of these isolates to host plants, dry weight, Root:Shoot ratio, colonization rates and N, P concentration of host plant showed host plant was affected differently by AM fungal isolates. This results suggest that AM fungi have high diversity in their functionality in intraspecific level, even in same population.

• 식물병연구
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• 제29권4호
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• pp.420-424
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• 2023

2020년 제주도 동백동산 내 구실잣밤나무 수피에 고약병과 관련된 Septobasidium sp.가 발견되었다. 분리한 균주는 습실 처리하여 새로 생성된 균사에 대한 genomic DNA를 추출한 뒤 internal transcribed spacer 및 small subunit rDNA 유전자에 대해 염기서열을 밝혔으며 polymerase chain reaction-based restriction fragment length polymorphism 분석을 통해 균주들간의 분자학적 특성이 조사되었다. 이 새로운 Septobasidium sp.은 기존에 알려진 고약병들과 형태학적 및 계통학적으로 다르게 나타나 새로운 종으로 보고한다. 또한 이 고약병은 관찰 당시 주변의 다른 수목들에서는 발생하지 않고 오직 구실잣밤 나무에서만 나타나는 특성으로 기주특이성이 매우 높다는 것이 확인되었다.