• Journal of the Korean Wood Science and Technology
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• v.38 no.3
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• pp.242-250
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• 2010

The aim of this study was to investigate the terpenoids of Total Volatile Organic Compounds (VOCs) released during drying of Cryptomeria japonica using the thermal extractor (TE). Considering the drying process of C. japonica, temperatures of TE were set at $27^{\circ}C$, $60^{\circ}C$, $80^{\circ}C$, $100^{\circ}C$, and $120^{\circ}C$, respectively. As the result, the emission factors of VOCs and terpenoids were increased as temperature increased. The amount of terpenoids included in VOCs emission factors were 87.5%, 81.6%, 83.6%, 90.1%, and 97.3% depending on above temperatures, respectively. Especially at$100^{\circ}C$ and $120^{\circ}C$, the amount of terpenoids were measured more than 90%. ${\delta}$-cadinene was the highest yield at each temperature and 32 types of terpenoids were collected. Emitted terpenoids were classified into the sesquiterpene group which consists of 15 carbon sources. These 32 sesquiterpenes were used for determining the useful bioactivity such as antifungal activity by the agar dilution. As the result, they showed the antifungal activity against Trichophyton rubrum, Trichophyton mentagrophytes, Microsporum gypseum. The 5,000 ppm concentration of terpenoids showed a strong activity with 100% against the 3 fungi. At the 1,000 ppm concentration of terpenoids, the antifungal activities against three fungi were 95.2%, 98.7%, and 97.3%, and their activities were a little inhibited at 100 ppm concentration.

• The Korean Journal of Mycology
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• v.25 no.2 s.81
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• pp.143-151
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• 1997

Interspecific hybrids between Aspergillus niger and Penicillium notatum (Tyr-), hyperlipolytic enzyme-producing fungi, were obtained by nuclear transfer technique. Optimal conditions for formation of intergeneric hybrids were investigated. Maximum production of protoplasts was obtained by 1% Novozyme 234 at $30^{\circ}C$ for 3 hrs and the most effective osmotic stabilizers for the isolation of protoplasts were 0.6 M KCl. Frequencies of hybrid formation by nuclear transfer were $3.8{\times}10^{-3}{\sim}1.3{\times}10^{-3}$. From the observation of genetic stability, conidial size, DNA content, and nuclear stain, it was suggested that their karyotypes are aneuploid. The hybrids showed $1.2{\sim}1.7$ fold higher lipase activities than parental strains. It was strongly supported by results of this study that nuclear transfer technique is much more efficient in the formation of intergeneric hybrids than protoplast fusion and is very useful for the improvement of strains.

• The Korean Journal of Mycology
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• v.41 no.4
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• pp.248-254
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• 2013

A Gram-negative bacterium was isolated from mushroom media that markedly reduces the level of extracellular toxins (i.e., tolaasins) produced by Pseudomonas tolaasii, the most destructive pathogen of cultivated mushrooms. The HC1 strain was selected as detoxifying tolaasin by bioassay on potato and it was identified Pseudomonas sp. by the cultural, morphological and physiological characteristics, and analysis of the 16S rRNA. The isolated bacterium is saprophytic but not parasitic nor pathogenic to cultivation mushroom. The isolated bacterium for P. tolaasii cell, was sufficient for detoxification in vitro. Inoculation of the isolated bacterium prevents the development of bacterial disease in Pleurotus ostreatus, Flammunia velutipes and Agaricus bisporus. Control efficacy of brown blotch of strain HC1 treatment was 69, 68 and 55% on Agaricus bisporus, Flammulina velutipes and Pleurotus ostreatus, respectively. The suppressive bacterium may be useful in future for the development of biocontrol system and the construction of genetically modified edible fungi resistant to the disease caused by P. tolaasii.

• Journal of Life Science
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• v.27 no.1
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• pp.72-77
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• 2017

Inorganic iron is essential for various metabolic processes, including RNA synthesis, electron transport, and oxygen detoxification in microorganisms. Many bacterial pathogens compete for iron acquisition in diverse environmental condition such as host. Salmonella Typhimurium SL1344 also requires inorganic iron as a cofactor for growth. When a M9 minimal liquid medium was supplemented with ethylenediamine di-o-hydroxyphenylactic acid (EDDA) which acts as an iron-chelating agent, growth of Salmonella Typhimurium SL1344 in the supplemented medium was completely arrested by deficient of useful iron under iron-depleted condition. However, a number of siderophores, which are small, high-affinity iron chelating compounds secreted by microorganisms such as bacteria and fungi, were produced for utilization of restricted iron under iron-depleted condition. A M9 minimal liquid medium complemented with human transferrin (hTf)-iron complex turned completely off production of siderophores, but growth of Salmonella Typhimurium SL1344 maintained level similar to compare one complemented with iron (III) chloride (FeCl3). This means that human transferrin (hTf)-bound iron can utilize via directly interaction with Salmonella Typhimurium SL1344 without productions of siderophores. Through construction and analysis of negative mutant for utilization of human transferrin (hTf)-bound iron, we confirm that the bacterium can directly use human transferrin (hTf)-bound iron without extracellularly intermediated carriers such as siderophores.

• The Korean Journal of Mycology
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• v.39 no.1
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• pp.16-21
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• 2011

Ginseng root rot caused by Cylindrocarpon destructans is one of the most destructive diseases of ginseng(Panax ginseng). We analyzed the features of the species through pathogenicity test and genetic diversity analysis of C. destructans in Korea, for its application as basic data to attempt for effective control. C. destructans isolated from rotted ginseng roots exhibited a variety of colonial colors on media. It was assumed that there may exist genetic diversity in the population by the diversity of pathogenicity among isolates observed when artificially inoculated into ginseng roots. Pathogenicity tests using ex vivo wound inoculation with agar mixture inoculation on ginseng roots were performed similar results as were observed appear to be useful for rapid pathogen inspection. According to RAPD analysis results, Korean C. destructans isolates formed a single genetic group which can be distinguished readily from closely related other fungi. C. destructans group was divided into two small groups. Therefore, we were able to confirm pathogenicity and genetic difference between the isolates in each of the groups of the pathogen.

• The Korean Journal of Mycology
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• v.41 no.1
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• pp.1-8
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• 2013

COP9 signalosome (CSN), which is originally identified as the regulator of the photomorphogenic development in plant, is highly conserved protein complex in diverse eukaryotic organisms. Most eukaryotic CSN complex is composed of 8 subunits, which is structurally and functionally similar to the lid subunit of 26S proteasome and eIF3 translation initiation complex. CSN play important functions in the regulation of cell cycle and checkpoint response by controlling Cullin-Ring E3 ubiquitin ligases (CRL) activities. CSN exhibits an isopeptidase activity which cleaves the neddylated moiety of cullin components. In fission yeast, S-phase cell cycle progression was delayed and the sensitivity to g-ray or UV was increased in CSN1 and CSN2 deletion mutants, indicating that yeast CSN is also involved in the checkpoint regulation. CSN in fungal system more closely resembles that of the higher organisms in the structure and assembly of their components. Functionally, CSN is associated with the regulation of conidiation rhythms in Neurospora crassa and the sexual development in Aspsergillus nidulans. Recent studies also revealed that CSN functions as an essential cell cycle regulator, playing key roles in the regulation of DNA replication and DNA damage response in Aspergillus. Overall, CSN of microorganisms, such as fission yeast and fungi, share functionally common aspects with higher organisms, implying that they can be useful tools to study the role of CSN in the CRL-mediated diverse cellular activities.

• Korean Journal of Food Science and Technology
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• v.46 no.1
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• pp.44-50
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• 2014

We evaluated the enzyme inhibitory activity of germinated rough rice (Oryza sativar L.) treated by high pressure (30MPa) for 24 h (HP24) and 48 h (HP48). In rice germinated for 1 day, the ${\alpha}$-glucosidase inhibitory activity reached its highest level, 68.32%, at HP48. The ${\alpha}$-amylase inhibitory activity increased from 32.66-57.00% at HP0, to 43.67-74.82% at HP48. On the other hand, the inhibitory activity of angiotensin-converting enzyme increased from 27.98% to 49.42% over the course of the second day of HP48. The inhibitory activity of xanthine oxidase peaked of 67.51% at HP48 and subsequently decreased. Lipase inhibitory activity increased from 24.04-47.91% at HP0, to 29.62-64.63% at HP48. These results provide useful information for the use of germinated rough rice as a functional food material and demonstrate that high-pressure treatment during the germination process efficiently increase enzyme inhibitory activity.

• Journal of Plant Biotechnology
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• v.45 no.3
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• pp.155-170
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• 2018

In this paper, mechanisms of gene editing technologies including ZFN, TALENS and CRISPR were briefly discussed with mutual advantages and disadvantages. Classification criteria of gene edited, site-directed mutagenesis (SDN) crops for regulatory purpose were also discussed. The number of studies using CRISPR technology was high and studies conducted on Arabidopsis thaliana and rice were highest, followed by tobacco, tomato, wheat, and corn. It has been applied to a variety of plants such as other grain crops, flower crops, vegetable crops, and fruit trees. The number of studies focused on practical application or commercialization in the future were also increasing yearly, and the scope of studies also expanded to include research on metabolic engineering for mass production of useful proteins or substances, development of disease resistant crops against viruses, bacteria, and fungi, abiotic environmental stressresistant crops, and increased yields. In addition to this, it was revealed that application range is becoming more diversified, including the development of parthenocarpic tomatoes, hybrid rice lines using male sterility and increased shattering resistance Brassica napus. It was also revealed that the number of CRISPR gene edited crops permitted by the USDA(APHIS) increases yearly, to be released in the international seed market soon.

• Research in Plant Disease
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• v.16 no.1
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• pp.41-47
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• 2010

A total of 10,753 oligotrophic bacteria were isolated from the cultivated soils of red-pepper infected by Phytophthora blight disease in various regions of Korea (Chungju, Anmyon, Taean, Andong, Eumsung and Goesan). Seven bacteria isolates among these collected resources were selected by the first screening of in vitro antagonistic assay against major several plant pathogenic fungi including Phytophthora capsici. Finally, strain 7F was selected by pot assay for a possible biological control agent against Phytophthora blight disease of pepper seedling in the greenhouse. Strain 7F was identified as Bacillus subtilis on the basis of its 16S rDNA sequence analysis and as standardized biochemical characteristics assay kits such as API20 NE. In the experiment of P. capsici zoospore infected red-pepper on the pot test, infection rate of red-pepper with nonetreatment to Phytophthora blight disease was 87%, while the rate was only 6% in the pot treated with strain 7F. This result indicated that the Bacillus subtilis strain 7F will be useful as a potential biocontrol agent for Phytophthora blight disease of red-pepper.

• Korean Journal of Clinical Laboratory Science
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• v.52 no.3
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• pp.229-236
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• 2020

Sixty-five molds isolated from clinical specimens were included in this study. All the isolates were molds that could be identified morphologically, strains that are difficult to identify because of morphological similarities, and strains that require species-level identification. PCR and direct sequencing were performed to target the internal transcribed spacer (ITS) region, the D1/D2 region, and the β-tubulin gene. Comparative sequence analysis using the GenBank database was performed using the basic local alignment search tool (BLAST) algorithm. The fungi identified morphologically to the genus level were 67%. Sequencing analysis was performed on 62 genera and species level of the 65 strains. Discrepancies were 14 (21.5%) of the 65 strains between the results of phenotypic and molecular identification. B. dermatitidis, T. marneffei, and G. argillacea were identified for the first time in Korea using the DNA sequencing method. Morphological identification is a very useful method in terms of the reporting time and costs in cases of frequently isolated and rapid growth, such as Aspergillus. When molecular methods are employed, the cost and clinical significance should be considered. On the other hand, the molecular identification of molds can provide fast and accurate results.