• Journal of Life Science
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• v.32 no.2
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• pp.119-124
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• 2022

To effectively isolate acetic acid bacteria for producing makgeolli vinegar, various products were researched, and Acetobacter pasteurianus CK-1, a strain that is excellent in acetic acid production, was finally isolated. The optimal growth temperature of the isolated strain was confirmed to be 30℃, and it grew well in the pH range of 5.5~6.5, with optimal growth at pH 6. A. pasteurianus CK-1 had the most active proliferation when the initial ethanol concentration in the medium was 4%, and growth was possible even at an ethanol concentration of 7%. When inoculating the isolated strain into makgeolli to induce acetic acid fermentation, the pH at the beginning of fermentation was 3.54, which was gradually lowered to 2.77 after 18 days of fermentation. The acidity was 0.75% at the beginning of fermentation and gradually started to increase from the 4th day of fermentation. The final acidity at the end of fermentation was 5.54%. In the vinegar fermented by inoculating A. pasteurianus CK-1, acetic acid content was detected to be as high as 3,575.7±48.6 mg%, and the malic acid and citric acid contents were 2,150.8±27.6 and 55.8±3.7 mg%, respectively. Further, it was confirmed that the content and ratio of the organic acids produced significantly differed depending on the type of inoculated bacterial strain. During acetic acid fermentation, the populations of yeast and A. pasteurianus CK-1 were inversely changed. In the initial stage of fermentation, yeast dominated, and after 10 days of fermentation, A. pasteurianus CK-1 slowly proliferated and reached stationary phase.

• Journal of Life Science
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• v.33 no.7
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• pp.538-548
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• 2023

The research has been conducted on the isolation of antimicrobial compounds from plant natural extracts and their potential application in oral health care products. This study aimed to investigate the antimicrobial mechanism by analyzing the changes in gene expression of Streptococcus mutans, a major oral pathogen, in response to complex compounds extracted from Aralia continentalis and Arctii Semen using organic solvents. Transcriptome analysis (RNA-seq) revealed that both natural extracts commonly upregulated or downregulated the expression of various genes associated with different metabolic and physiological activities. Three genes (SMU_1584c, SMU_2133c, SMU_921), particularly SMU_921 (rcrR), known as a transcription activator of two sugar phosphotransferase systems (PTS) involved in sugar transport and biofilm formation, exhibited consistent high expression levels. Additionally, component analysis of the A. continentalis extract was performed to compare its effects on gene expression changes with the A. Semen extract, and two active compounds were identified through gas chromatography-mass spectrometry (GC-MS) analysis of the active fraction. The n-hexane fraction (ACEH) from the A. continentalis extract exhibited antibacterial specificity against S. mutans, leading to a significant reduction in the viable cell counts of Streptococcus sanguinis and Streptococcus gordonii among the tested multi-species bacterial communities. These findings suggest the broad-spectrum antibacterial activity of the A. continentalis extract and provide essential foundational data for the development of customized antimicrobial materials by elucidating the antibacterial mechanism of the identified active compounds.

• Journal of the Korean Applied Science and Technology
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• v.40 no.5
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• pp.1126-1135
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• 2023

Nine microbial strains were isolated from the byproduct of ginseng processing and field of ginseng cultivation. Two strains among them were confirmed. Phylogenetic analysis of these 𝛽-Glucosidase strains confirmed that strain GYP-1 belongs to the Rhodotorula and strain GYP-3-3 belong to genus Brachybacterium. Rhodotorula sp. GYP-1 was finally selected due to its high biomass production. The 𝛽-Glucosidase activity of Rhodotorula sp. GPY-1 was assessed at 30 ℃, and Higher than 70% of the enzyme activity was maintained at the temperature range of 20-40℃. Although the optimum pH for the highest enzyme activity was pH 5.0, the enzyme was stable throughout the pH range of 5.0-8.0. In addition, Rhodotorula sp. demonstrated antifungal activity against the ginseng root rot disease caused by Botrytis.

• The Korean Journal of Mycology
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• v.51 no.4
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• pp.511-519
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• 2023

Red pine (Pinus densiflora) is a dominant tree species in Korean forests. The diversity of endophytic fungi was investigated by isolating fungi from different parts of a red pine tree during the fall and spring seasons. One hundred and fifty-two strains of endophytic fungi were isolated and classified into 42 species belonging to 29 genera. Among these, 74 (49%), 47 (31%) and 31 strains (20%) were isolated from branches, leaves, and stems, respectively. The most frequently isolated species were Daldinia childiae and Biscogniauxia maritima (28.9% and 9.8%, respectively). D. childiae was the dominant endophytic fungus on branches (20 strains) and leaves (19 strains). B. maritima was most frequently isolated from branches. The isolation frequencies on stems of B. maritima (6 strains) and D. childiae (5 strains) were also high. Fifty-seven isolates belonging to 19 species and 17 genera were isolated in the spring, and 95 strains belonging to 35 species and 24 genera were isolated in the fall. D. childiae was the most frequently isolated fungus in both spring and fall (21 and 23 strains, respectively). B. maritima was also frequently isolated in both spring (7 strains) and fall (8 strains).

• Journal of the Korea Institute of Military Science and Technology
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• v.27 no.4
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• pp.507-515
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• 2024

Microbial forensics is a scientific discipline for analyzing evidence related to biological crimes by identifying the origin of microorganisms. Multiple locus variable number tandem repeat analysis(MLVA) is one of the microbiological analysis methods used to specify subtypes within a species based on the number of tandem repeat in the genome, and advances in next generation sequencing(NGS) technology have enabled in silico anlysis of full-length whole genome sequences. In this paper, we analyzed unknown samples provided by Robert Koch Institute(RKI) through The United Nations Secretary-General's Mechanism(UNSGM)'s external quality assessment exercise(EQAE) project, which we officially participated in 2023. We confirmed that the 3 unknown samples were B. anthracis through nucleic acid isolation and genetic sequence analysis studies. MLVA results on 32 loci of B. anthracis were analysed by using genome sequences obtained from NGS(NextSeq and MinION) and Sanger sequencing. The MLVA typing using short-reads based NGS platform(NextSeq) showed a high probability of causing assembly error when a size of the tandem repeats was grater than 200 bp, while long-reads based NGS platform(MinION) showed higher accuracy than NextSeq, although insertion and deletion was observed. We also showed hybrid assembly can correct most indel error caused by MinION. Based on the MLVA results, genetic identification was performed compared to the 2,975 published MLVA databases of B. anthracis, and MLVA results of 10 strains were identical with 3 unkonwn samples. As a result of whole genome alignment of the 10 strains and 3 unknown samples, all samples were identified as B. anthracis strain A4564 which is associated with injectional anthrax isolates in heroin users.

• Journal of the Korea Institute of Military Science and Technology
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• v.27 no.1
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• pp.116-125
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• 2024

The COVID-19 pandemic is not over despite the emergency use authorization as can see recent COVID-19 daily confirmed cases. The viruses are not only difficult to diagnose and treat due to random mutations, but also pose threat human being because they have the potential to be exploited as biochemical weapons by genetic manipulation. Therefore, it is inevitable to the rapid antibody-based therapeutic platform to quickly respond to future pandemics by new/re-emerging viruses. Although numerous researches have been conducted for the fast development of antibody-based therapeutics, it is sometimes hard to respond rapidly to new viruses because of complicated expression or purification processes for antibody production. In this study, a novel rapid antibody-based therapeutic platform using single B cell sorting method and mRNA-antibody. High immunogenicity was caused to produce antibodies in vivo through mRNA-antigen inoculation. Subsequently, antigen-specific antibody candidates were selected and obtained using isolation of B cells containing antibody at the single cell level. Using the antibody-based therapeutic platform system in this study, it was confirmed that novel antigen-specific antibodies could be obtained in about 40 days, and suggested that the possibility of rapid response to new variant viruses.

• Journal of Applied Biological Chemistry
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• v.66
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• pp.477-483
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• 2023

The flowers of Carthamus tinctorius (Safflower) were extracted with 80% aqueous methanol (CTex) and the concentrates were partitioned into EtOAc (CTE), n-BuOH (CTB), and H₂O (CTW) fractions. Repeated silica gel (SiO₂) and octadecyl silica gel column chromatographies for the EtOAc and n-BuOH fractions led to isolation of four flavonol glycosides. Nuclear magnetic resornance, infrarad spectroscopy, and mass spectroscopy revealed the chemical structure of the isolated compounds, astragalin (1), isoquercetin (2), nicotiflorin (3), and rutin (4). Quantitative analysis of four isolated compounds in CTex was performed by HPLC. CTex was found to contain 1 at 0.107, 2 at 0.367, 3 at 6.752, and 4 at 0.991 mg/g, respectively. Through this study, an experiment was conducted to evaluate the protective effect on pancreatic islets of the extract, solvent fractions, and all isolated compounds using a zebrafish larvae damaged by alloxan. Pancreatic islet size treated with EtOAc (CTE), n-BuOH (CTB), and H₂O (CTW) fractions and compounds 1-4 significantly increased compared to the alloxan-induced group. These results indicate that C. tinctorius flowers and its isolated compounds are used as potential anti-diabetic agents.

• Food Science of Animal Resources
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• v.30 no.1
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• pp.87-94
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• 2010

The aim of the present study was to develop polyclonal antibodies to regional inedible adipocytes of pigs and investigate the effect of these antibodies on adipocytes in vitro. As antigens, abdominal and subcutaneous adipocyte PMPs from pigs were injected into sheep 3 times per 3 wk intervals for passive immunization, and non-immunized serum, antisera against abodominal (AAb) or subcutaneous adipocyte PMPs (SAb) were collected before and after the injections. Titers of the antisera obtained from sheep and their cross-reactivities with the heart, kidney, liver, lung, muscle, and spleen of pig were determined by ELISA. Isolation and culture of abdominal and subcutaneous adipocytes from pigs were performed to analyze LDH concentration. At a 1:1,000 dilution, little antibody reactivity was observed for non-immunized serum whereas both AAb and SAb had relatively strong reactivity up to a dilution of 1:16,000. These findings may indicate that strong antibodies against adipocyte PMPs can be developed using an immunological approach. Extremely low reactivity of AAb and SAb was detected with the PMPs of the organs. Both antisera most strongly reacted with each adipocyte PMPs and showed statistically (p<0.05) higher cross-reactivities compared with the non-immunized serum. In conclusion, these results may indicate that the present polyclonal antibodies against regional inedible adipocyte PMPs are well developed and are safe against cross-reactivities with the organs of pigs. Further studies on the in vivo nutritional safety and fat reduction of these antibodies in pigs will be required fat-reduced high quality pork production.

• Korean Journal of Environment and Ecology
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• v.22 no.3
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• pp.309-319
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• 2008

Roads are an indicator of anthropogenic activity causing ecosystem disturbances and often lead to habitat fragmentation, habitat loss, and habitat isolation. The Hallasan National Park(153.4$km^2$) on Jeju Island being distinguished for its unique geology, topography, and biota has also been designated as a core area of UNESCO Man and the Biosphere(MAB) Reserve. Although the high conservation value of this park has contributed to a rapid growth of tourists and road construction, landscape changes due to roads have not been examined yet. We used GIS systems to examine the fragmentation pattern caused by roads, in relation to its zonation, elevation, and vegetation. When a buffer was applied to roads(112m width for paved roads and 60m width for both legal and illegal trails), the park consisted of 100 fragments. The ten fragments generated after applying buffer to only paved roads and legal trails ranged from $0.002km^2$ to $38.2km^2$ with a mean of $14.2km^2$, and about 7% of both nature conservation zone and nature environment zone of the park were edge. Fragments in both east and west ends of the park and around the summit exhibited relatively high shape indices with means of 5.19(for 100 fragments) and 7.22(for 10 fragments). All five legal trails are connected to the pit crater of the mountain and vegetation changed from broadleaf forests and conifer forests to grasslands with elevation, consequently resulting in dramatic fragment size reduction in grasslands at high elevation, in particular above 1,400m, where endemic and alpine plants are abundant. These results show that in Hallasan National Park the risks of habitat deterioration and habitat loss due to fragmentation may be more severe in the nature conservation zone dominated by Baengnokdam than in the nature environment zone. Therefore, current road networks of the park appear to fall short of the goal of the national park for ecosystem conservation and protection. Considering that the entire Hallasan National Park also serves as a MAB core area, conservation efforts should focus, first of all, on park rezoning and road management to mitigate habitat fragmentation.

• KSBB Journal
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• v.25 no.2
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• pp.155-166
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• 2010

Studies on the production of cell-wall bound innerpolysaccharides (IPS) (soluble ${\beta}$-D-glucan) have been performed by use of suspended myelial cultures of Inonotus obliquus. This product has promising potentials as an effective antidiabetic as well as an immunostimulating agents. As a first step to enhanced production of IPS, Intensive strain improvement programs were carried out by obtaining a large amounts of protoplasts for the isolation of single cell colonies. Rapid and large screening of high-yielding producers was possible because about fivefold higher amount of protoplasts ($2.3{\times}10^6$ protoplasts/mL) could be recovered with relatively high regeneration rates of $10^{-2}{\sim}10^{-3}$ by applying a modified filtration method, as compared to the previously used trapping method. A basic protocol necessary for UV-mutation of the protoplasts was also developed, resulting in several overproducing variants with good fermentation properties. Since the amount of IPS extracted from the mycelial cell walls of I. obliquus turned out to be almost constant per g DCW, increase in cell mass was considered the most important factor for the enhancement in IPS production. Therefore, attempts were made to screen mutant cells showing rapid mycelial growth rate in the final suspended cultures. Notably, the mutant strains showing an active cellgrowth in the preceding solid growth cultures were observed to produce higher amount of IPS in the suspended fermentations as well. A striking mutant, OBLQ756-15-5 strain, obtained from the survivors of a harsh UV-treated condition (97% death rate) was found to stably produce as high cell mass as 22 g DCW/L in the final fermentations. Currently, this strain is being tested for development of a scaled-up fermentation process for mass production of IPS.