• Journal of Life Science
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• v.29 no.1
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• pp.84-89
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• 2019

Previous screening of novel antibacterial agents revealed that some bacterial isolates exhibited antibiotic activity against both gram-positive and gram-negative bacteria and that they showed antibacterial activity, even against methicillin-resistant Staphylococcus aureus (MRSA). Among these isolates, one bacterial strain, BCNU 1204, was identified as Pseudomonas aeruginosa using phenetic and phylogenetic analysis, based on 16S ribosomal RNA gene sequences. The maximum productivities of antimicrobial substances of BCNU 1204 were obtained after being cultured at $35^{\circ}C$ and pH 7.0 for 4 d in King's medium B (KMB). Dichloromethane (DCM) and ethylacetate (EA) extracts of P. aeruginosa BCNU 1204 exhibited strong antimicrobial activity, particularly against gram-positive bacteria. The EA extracts exhibited broad-spectrum activity against antibiotic resistant strains. Fraction 5-2, was obtained by recycling preparative liquid chromatography (LC) and preparative thin-layer chromatography (TLC) and was identified as phenazine-1-carboxylic acid belonging to phenazines using gas chromatography and mass spectrometry (GC/MS). Its minimum inhibitory concentration (MIC) values were $25{\mu}g/ml$, $50{\mu}g/ml$, ${\geq}25{\mu}g/ml$, and ${\geq}50{\mu}g/ml$ for MRSA CCARM 3089, 3090, 3091, and 3095 strains, respectively. P. aeruginosa BCNU 1204 may be a potential resource for the development of anti-MRSA antibiotics. Additional research is required to identify the active substance from P. aeruginosa BCNU 1204.

• Journal of Life Science
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• v.29 no.5
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• pp.614-620
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• 2019

The purpose of this study was to examine the growth plate, femoral bone length, bone mineral density, and blood composition in various experimental animals fed with oriental medicinal herbs containing growth factors. First, the lengths of the bone growth plates of the positive control (PC) group (fed with Astragalus membranaceus) and the Gh-199 and Sh-188 groups were increased when compared to group N. The Gh-199 group showed a greater increase in bone growth when compared with the PC group. In terms of the femoral bone length and bone mineral density, the effect of both Gh-199 and Sh-188 powders were as good as those of the PC group, and the Gh-199 powder showed a positive effect. Conversely, in the PC group, unlike the Gh-199 and Sh-188 groups, the aspartate aminotransferase(AST) and alanine aminotransferase(ALT) activities in the blood were increased, indicating that A. membranaceus is toxic to the body. Both the PC and Sh-188 groups also showed higher insulin-like growth factor-1(IGF-1) activity when compared with the Gh-199 group. Overall, the bone growth plate, femoral bone length, and bone mineral density measurements, and the blood analysis showed positive results in the group treated with Gh-199, and no specific toxicity of the herbal medicine in the body was evident.

• Journal of Life Science
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• v.31 no.1
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• pp.73-82
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• 2021

Throughout history, barley was the typical crop of the soils of Jeju Island due to its topographical features. People in Jeju eat Shindari or Dansul. Shindari or Dansul is a fermented drink of Jeju, made from the leftovers of cooked barely and nuruk of short fermentation periods. Although Makgeolli and Shindari share a similar fermentation period and materials, research on Shindari or Dansul is still in its early stages. In this study, we examined major bacterial species of Shindari or Dansul. In addition, we confirmed the antibacterial activities of an isolated strain against fish and human-harmful bacteria. Among the isolates, Firmicutes consisted of 73% and the Proteobacteria of 27%, indicating that the Firmicutes phylum was the dominant one. In addition, the Pediococcus genus and the Bacillus genus were the most prevalent consisting of 25%, followed by the Cronobacter genus (25%), the Enterococcus genus (16%), the Aneurinibacillus genus (5%), the Klebsiella genus (4%), and the Paenibacillus genus (2%). We conclude that the Lactobacillus genus predominated in Makgeolli, but the Pediococcus genus predominated in Shindari. In a study of the antibacterial activity, growth inhibition was observed for all bacteria, except for the fish disease bacterium Photobacterium damselae subsp. piscicida and the human-harmful bacterium Streptococcus mutans.

• Journal of Life Science
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• v.31 no.1
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• pp.52-58
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• 2021

Pseudomonas syringae pv. actinidiae, which causes bacterial canker in kiwifruit, is divided into five biovars (1, 2, 3, 5, 6) on the basis of genetic characteristics and toxin productivity. Among them, biovar 3 is responsible for the current global outbreak, and has been isolated in Korea since 2011. Biovar 3 strains isolated from Korea are subdivided into six genetically different lineages (subgroup I, IV, V, VI, VII, and VIII) based on random amplified polymorphic DNA (RAPD) analysis. In this work, the subgroup-specific sequence characterized amplified region (SCAR) primers were developed from sequenced differential RAPD bands. Distribution of the subgroups of the biovar 3 strains collected in Korea from 2011-2017 were examined using these subgroup-specific primer sets. Among the 54 strains tested, 35 strains (64.8%) belonged to subgroup V, 9 strains (16.7%) belonged to subgroup IV, 4 strains (7.4%) belonged to subgroup VI, 3 strains (5.6%) belonged to subgroup VII, 2 strains (3.7%) belonged to subgroup VIII, and 1 (1.9%) strain belonged to subgroup I. Strains belonging to subgroups IV, V, and VI were shown to be related to strains isolated from China, New Zealand, and Chile, respectively. The study revealed that the biovar 3 strains in Korea are genetically diverse and are estimated to have been introduced through pollen sourced from foreign countries.

• Journal of Life Science
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• v.31 no.7
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• pp.654-661
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• 2021

In this study, in order to isolate excellent whitening agents from fungal cultural broth, various fungi were collected from wild areas in South Korea and then screened for tyrosinase inhibition activity, as tyrosinase is a precursor for the biosynthesis of melanin in regulating skin color. A fungus strain that inhibits tyrosinase activity has been identified and confirmed as Trichoderma viridescens (later renamed T. viridescens SW-1) via ITS sequencing. In T. viridescens SW-1, tyrosinase inhibitory activity was strongest on day three of culture. A 5% culture broth showed a tyrosinase inhibitory activity greater than 90% and exhibited high thermostability on day three. At 10% culture broth, the accumulations of intra- and extracellular melanin were inhibited above 27.1% and 7.5%, respectively. In summary, the physical and functional properties of the tyrosinase inhibitory substances of T. viridescens SW-1 included high levels of inhibition of melanin synthesis and antioxidative activity as well as thermostability. Therefore, we suggest that the whitening substance identified from the cultural broth of T. viridescens SW-1 has potential for application as a functional cosmetic ingredient.

• Journal of Life Science
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• v.33 no.11
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• pp.944-949
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• 2023

The purpose of this study was to identify conserved metabolic pathways and conserved genes in 122 archaeal species. Using the Clusters of Orthologous Groups of Proteins (COG) database of conserved genes, we analyzed whether 122 species had 63 COG metabolic pathways, the 822 COGs that compose them, and a total of 4,877 COGs. Archaeal ribosomal proteins were the most conserved in metabolic pathways. 46 COGs in seven COG pathways among 63 COG pathways and 20 COGs in others were conserved in 122 species. Some genes involved in cell wall and extracellular matrix synthesis, replication, transcription, translation, and protein metabolism were common to all 122 species. When the distance value of the phylogenetic tree was analyzed at the phylum level or class level, the average was the lowest at the class Halobacteria of the phylum Euryarchaeota. Standard deviation was high for the class Nitosospharia of the phylum Thaumarchaeota, the unclassified members of phylum Thaumarchaeota, the class Halobacteria of the phylum Euryarchaeota, the class Thermoprotei of the phylum Crenarchaeota, and other archaea. Furthermore, the phylogenetic tree analysis revealed six commonalities. The results of this study, along with data on conserved genes, could be used for drug development and gene selection for strain improvement.

• Journal of Korean Neurosurgical Society
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• v.67 no.3
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• pp.333-344
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• 2024

Objective : Markers of neuroinflammation during ischemic stroke are well characterized, but additional markers of neural damage are lacking. The study identified associations of behavioral disorders after stroke with histologic neural damage and molecular biological change. Methods : Eight-week-old, 25 g male mice of the C57BL/6J strain were subjected to middle cerebral artery occlusion (MCAO) to induce ischemic stroke. The control group was a healthy wild type (WT), and the experimental group were designed as a low severity MCAO1 and a high severity MCAO2 based on post-stroke neurological scoring. All groups underwent behavioral tests, realtime polymerase chain reaction, triphenyltetrazolium chloride (TTC) staining and Hematoxylin and Eosin staining. One-way analysis of variance was used to analyze statistical significance between groups. Results : In TTC staining, MCAO1 showed 29.02% and MCAO2 showed 38.94% infarct volume (p<0.0001). The pro-inflammatory cytokine interleukin (IL)-1β was most highly expressed in MCAO2 (WT 0.44 vs. MCAO1 2.69 vs. MCAO2 5.02, p<0.0001). From the distance to target in the Barnes maze test, WT had a distance of 178 cm, MCAO1 had a distance of 276 cm, and MCAO2 had a distance of 1051 (p=0.0015). The latency to target was 13.3 seconds for WT, 27.9 seconds for MCAO1, and 87.9 seconds for MCAO2 (p=0.0007). Prospero homeobox 1 (Prox1) was most highly expressed in MCAO2 (p=0.0004). Doublecortin (Dcx) was most highly expressed in MCAO2 (p<0.0001). Conclusion : The study demonstrated that histological damage to neural cells and changes in brain mRNA expression were associated with behavioral impairment after ischemic stroke. Prox1 and Dcx may be biomarkers of neural damage associated with long-term cognitive decline, and increased expression at the mRNA level was consistent with neural damage and long-term cognitive dysfunction.

• Microbiology and Biotechnology Letters
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• v.44 no.3
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• pp.400-407
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• 2016

A unicellular green alga, Chlorella vulgaris KNUA027, was isolated from the roots of Panax ginseng seedlings and its biotechnological potential was investigated. The results of GC/MS analysis showed that C. vulgaris KNUA027 was rich in nutritionally important polyunsaturated fatty acids (PUFAs) such as alpha-linolenic acid (C_18:3 ω3, 45.8%, 50.8 mg/g) and hexadecatrienoic acid (C_16:3 ω3, 11.8%, 13.1 mg/g). Therefore, this Korean indigenous microalga may have potential as a source of omega-3 PUFAs. It was also found that the saturated palmitic acid (C_16:0, 37.1%, 41.2 mg/g), which is suitable for biodiesel production, was one of the major fatty acids produced by strain KNUA027. The proximate analysis showed that the volatile matter content was 88.5%, and the ultimate analysis indicated that the higher heating value was 19.8 MJ/kg. Therefore, the results from this research with C. vulgaris KNUA027 may provide the basis for the production of microalgae-based biofuels and biomass feedstock.

• Journal of Life Science
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• v.26 no.10
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• pp.1121-1129
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• 2016

High-molecular-weight glutenin subunits (HMW-GSs) are extremely important determinants of the functional properties of wheat dough. Transgenic rice plants containing a wheat TaGlu-Ax1 gene encoding a HMG-GS were produced from the Korean wheat cultivar ‘Jokyeong’ and used to enhance the bread-making quality of rice dough using the Agrobacterium-mediated co-transformation method. Two expression cassettes with separate DNA fragments containing only TaGlu-Ax1 and hygromycin phosphotransferase II (HPTII) resistance genes were introduced separately into the Agrobacterium tumefaciens EHA105 strain for co-infection. Rice calli were infected with each EHA105 strain harboring TaGlu-Ax1 or HPTII at a 3:1 ratio of TaGlu-Ax1 and HPTII. Among 210 hygromycin-resistant T₀ plants, 20 transgenic lines harboring both the TaGlu-Ax1 and HPTII genes in the rice genome were obtained. The integration of the TaGlu-Ax1 gene into the rice genome was reconfirmed by Southern blot analysis. The transcripts and proteins of the wheat TaGlu-Ax1 were stably expressed in rice T₁ seeds. Finally, the marker-free plants harboring only the TaGlu-Ax1 gene were successfully screened in the T₁ generation. There were no morphological differences between the wild-type and marker-free transgenic plants. The quality of only one HMW-GS (TaGlu-Ax1) was unsuitable for bread making using transgenic rice dough. Greater numbers and combinations of HMW and LMW-GSs and gliadins of wheat are required to further improve the processing qualities of rice dough. TaGlu-Ax1 marker-free transgenic plants could provide good materials to make transgenic rice with improved bread-making qualities.

• Journal of Life Science
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• v.17 no.11
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• pp.1562-1570
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• 2007

This experiment was conducted to develop fertilizer which promotes plant growth as well as suppressing pathogenic fungi. The fertilizer was made from the mixture of Ju-Back (Korean rice wine cake) and indigenous rhizosphere-bacterium. The main ingredients of Ju-Back were investigated as 6.04% total nitrogen, 42.59% total carbohydrate, 1.01% available phosphate, 73.42% organic matter, 7.72% potassium oxide, 1.35% calcium oxide, 0.53% magnesium oxide. The enzyme activities of Ju-Back were estimated to be 980 units/g for ${\alpha}-amylase$, 300 units/g for glucoamylase, and 1800 units/g for acid pretense. Indigenous rhizosphere bacteria which produced antifungal agent were isolated from soil, and was selected KMU-13 strain which can antagonize against various plant pathogenic fungi (Botrytis cinerea KACC 40573, Sclerotinia sclerotiorum KACC 41065, Fusairum oxysporum KACC 40052, Pythium aphanidermatum KACC 40156, Phytophthora capsici KACC 40476 and Glomerella cingulata KACC 40299). KMU-13 strain was identified as Bacillus subtilis KMU-13 by biochemical and 16s rDNA analysis. The organic fertilizer was made as prototype which was composed 20% Ju-Back, 70% carrier, 9.7% microorganism cultivated solution, 0.3% trace-element. We also investigated an application of fertilizer using Ju-Back for cultivating lettuce (Lactuca sativar) which were grown in three soil conditions that had chemical fertilizer, barnyard manure, lime power, urea, potassium chloride and superphosphate as a control, the whole quantity (80 kg/10a) of posted fertilizer with the control and the half quantity (40 kg/10a) with the control. The growth characteristics were examined and analysed with several weeks interval from 3 weeks to 8 weeks on head length (cm), head width (cm/head), number of leaf and fresh weight (g/plant). The results are summarized as follows. The head width and fresh weight of lettuce were the highest at posted fertilizer 1 (whole quantity) was applied chemical, organic matter (Ju-Back) and carrier. The head length was the highest at posted fertilizer 2 (whole quantity) was applied Ju-Back only.