• The Journal of Korean Academy of Prosthodontics
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• v.46 no.2
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• pp.116-124
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• 2008

Statement of the problem: Implant systems result in gaps and cavities between implant and abutment that can act as a trap for bacteria and thus possibly cause inflammatory reactions in the peri-implant soft tissues. Purpose: Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythia, Treponema denticola, and Aggregatibacter actinomycetemcomitans, related to implant-abutment interface microleakage. Material and methods: Samples were taken from 27 subjects with sterilized paper points and were transported in $1{\times}PBS$. The detection of periodontopathogens were performed by polymerase chain reaction with species-specific primers based on 16S rDNA. Results: Our data showed that the detection rate of P. gingivalis and P. intermedia in implant fixture was 59% and 82% in patients respectively. Detection rate of P. gingivalis and P. intermedia in implant crevice was 44% and 82% in patients. Detection rate of P. gingivalis and P. intermedias in tongue was 82% and 82% in patients. Conclusion: Current implant systems cannot safely prevent microbial leakage and bacterial colonization of the inner part of the implant.

• Korean Journal of Food Science and Technology
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• v.46 no.4
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• pp.438-445
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• 2014

We examined biogenic amine (BA) production as well as the diversity of bacterial flora in 11 types of commercial makgeolli stored at 4 and $20^{\circ}C$. Moreover, we studied the BA-producing activity of three L. plantarum strains isolated from makgeolli. At $20^{\circ}C$, the BA content was highly increased and the denatured DNA bands were more variable in non-sterilized makgeolli compared to sterilized makgeolli. The major BAs produced in commercial makgeolli were histamine and putrescine. Histamine, tyramine, putrescine, and cadaverine were produced in excess by inoculation of the three L. plantarum isolates to makgeolli stored at $20^{\circ}C$ for 21 days. These results suggest that some L. plantarum strains in makgeolli can produce different types of BAs, depending on the extent of degradation of makgeolli.

• Journal of agriculture & life science
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• v.46 no.3
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• pp.37-45
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• 2012

To select bacterial strains with antifungal activity against an anthracnose fungal disease causing damage severely on hot pepper, previous isolates obtained from plant root samples were screened. Among 457 isolates, IA70-5 isolate was finally selected and identified as Streptomyces padanus based on 16S rDNA sequence analysis. Strain IA70-5 is non-pigmenteous, non-mobile, and filamentous. S. padanus IA70-5 inhibited effectively the mycelium growth, spore germination, and appressorium formation of Colletotrichum acutatum in vitro. The results of this study demonstrated that IA70-5 strain, especially applied on fruit of hot pepper, decreased disease incidence 90% for pre-inoculation before pathogen treatment. Taken together, S. padanus IA70-5 strain is a promising biological control agent to control of a major fungal pepper disease, anthracnose.

• Journal of Life Science
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• v.32 no.10
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• pp.803-811
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• 2022

Despite the importance of traditional Korean fermented foods, little is known about the microbial communities and diversity of fermented soy products. To gain insight into the unexplored microbial communities of both Doenjang (DJ) and Ganjang (GJ) that may contribute to the fermentation in Korean traditional foods, we carried out next-generation sequencing (NGS) based on the V3-V4 region of 16S rDNA gene analysis. The alpha diversity analysis results revealed that both the Shannon and Simpson diversity indices were significantly different between the two groups, whereas the richness indices, including ACE, CHAO, and Jackknife, were not significant. Firmicutes were the most dominant phylum in both groups, but several taxa were found to be more abundant in DJ than in GJ. The proportions of Bacillus, Kroppenstedtia, Clostridium, and Pseudomonas and most halophiles and halotolerant bacteria, such as Tetragenococcus, Chromohalobacter, Lentibacillus, and Psychrobacter, were lower in DJ than in GJ. Linear discriminant effect size (LEfSe) analysis was carried out to discover discriminative functional biomarkers. Biomarker discovery results showed that Bacillus and Tetragenococcus were identified as the most important features for the classification of subjects to DJ and GJ. Paired-permutational multivariate analysis of variance (PERMANOVA) further revealed that the bacterial community structure between the two groups was statistically different (p=0.001).

• Journal of Life Science
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• v.34 no.6
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• pp.377-384
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• 2024

Prodigiosin is a red pigment characterized by a common pyrrolylpyrromethane skeleton. It is produced by Serratia marcescens, Vibrio psychroerythrus, Hahella chejuensis, etc. Prodigiosin has been reported to possess anticancer, immunosuppressant, antifungal antimalarial, and algicidal activities. However, despite prodigiosin's diverse range of activities, its production rate is significantly low and biosynthesis conditions are difficult. Consequently, the selling price is high, and its usability is limited. This study aimed to increase the efficiency of prodigiosin production according to the culture conditions of Serratia. In this study, a bacterial strain PDGS¹²⁰⁹¹⁵ producing prodigiosin was isolated from lightly contaminated stream water in Busan and identified as a strain of Serratia sp. based on 16S rDNA gene sequence analysis and physiological characteristics. The reddish pigment from PDGS¹²⁰⁹¹⁵ was directly extracted using acidified ethanol, and a characterization analysis confirmed that it was a prodigiosin compound. The optimal conditions for pigment production were 25℃, pH 7, and 0% NaCl concentration for a duration of 14 hr. Furthermore, by treating carbon and nitrogen sources, such as fructose and beef extract, respectively, prodigiosin production increased approximately six-fold and four-fold. Among the minerals tested, 0.1% KCl was found to be the most effective for prodigiosin production. Moreover, casein was identified as the most suitable source for prodigiosin production.

• International Journal of Industrial Entomology and Biomaterials
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• v.12 no.2
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• pp.57-61
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• 2006

Suppressor of cytokine signaling (SOCS) is known to be as a negative feedback regulator in Janus kinase signal transducer and activator of transcription signaling. Highly conserved SOCS box domain was cloned from a Korean malaria vector, Anopheles sinensis. Sequence analysis indicates that it has identity to Anopheles gambiae (96%), Aedes aegypti (94%), Drosophila melanogaster (78%), Mus musculus (72%) and Homo sapiens (72%), respectively. Tissue specificity RT-PCR demonstrated that the expression level of AsSOCS transcript was high at abdomen, midgut, and ovary, whereas developmental expression patterns showed that the level of AsSOCS was high at egg, early pupae, and adult female. On the other hand, RT-PCR analysis after bacterial challenge showed that SOCS mRNA was strongly induced in larvae. In addition, it was also induced by various immune elicitors such as lipoteicoic acid, CpG-DNA, and laminarin. It seems that AsSOCS, repressor of JAK-STAT pathway, is highly conserved in mosquito, and may play an important role in mosquito innate immune response.

• Journal of Microbiology and Biotechnology
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• v.8 no.5
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• pp.455-460
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• 1998

In the course of screening for new antitumor substances, a novel cytotoxic agent inducing apoptotic cell death was isolated from the culture broth of marine bacterial strain SCRC A-20. Strain SCRC A-20 was separated from a mollusk and was chemotaxonomically identified as a Streptomyces sp. The cytotoxic substance was purified by organic solvent extraction followed by silica gel column chromatography and preparative TLC. HRFAB-MS determined its molecular formula to be $C_{30}H_{40}N_2O_5$ (MW 508). The 1D and 2D NMR spectral data demonstrated that the substance has a novel lactam structure of a 20-membered macrocycle coupled with a unique acyl tetramine and bicyclo［3.3.0］ octane, which includes three methyl groups, six olefinic protons, five carbonyl groups, a conjugated diene and a dienone. The substance, named aburatubolactam C, appeared to be cytotoxic for various continuously proliferating tumor cells of human and murine origins. The $IC_{50}$ values determined by MIT assay were in the range of 0.3 to $5.8\mug/ml$. When Jurkat T cells were treated with $3\mug/ml$. of aburatubolactam C, the apoptotic DNA fragmentation was detectable within 3 h, indicating that the cytotoxic effect of aburatubolactam C on tumor cells is attributable to the induced apoptosis.

• Journal of Microbiology and Biotechnology
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• v.21 no.6
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• pp.659-664
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• 2011

Staphylococcus aureus (SA) bacteremia is associated with high mortality, and often results in metastatic infections. The methicillin-resistant SA (MRSA) is an urgent health care issue, as nosocomial infections with these bacteria represent limited treatment alternatives. Samples of whole blood containing challenge inoculums of SA and MRSA strains were passed through columns packed with surfaceheparinized polyethylene beads. The bound bacteria were eluted and quantitatively determined by culturing and by real-time PCR. Significant amounts of both SA and MRSA adhered to the heparinized beads (more than 65% of inoculated bacteria). After rinsing with buffer at high ionic strength, viable bacteria or bacterial DNA were eluted from the columns, indicating that the binding was specific. The conclusions that can be made from these experiments are that, as earlier reported in the literature, the high affinity of SA to heparin is retained in whole blood, and MRSA in whole blood binds to heparin with similar or higher affinity than SA. It should be possible to lower the amount of SA and/or MRSA from the blood of infected patients to levels that could be taken care of by the immune system. In previous studies, we have shown that passing blood from septic patients over beads coated with end-point-attached, biologically active heparin is a useful technique for regulating the levels of heparinbinding cytokine. These findings in combination with the present findings indicate the possibility of creating an apheresis technology for treatment of sepsis caused by SA and/or MRSA.

• Mycobiology
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• v.40 no.1
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• pp.59-65
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• 2012

Antagonistic microorganisms against $Rhizoctonia$ $solani$ were isolated and their antifungal activities were investigated. Two hundred sixteen bacterial isolates were isolated from various soil samples and 19 isolates were found to antagonize the selected plant pathogenic fungi with varying degrees. Among them, isolate C9 was selected as an antagonistic microorganism with potential for use in further studies. Treatment with the selected isolate C9 resulted in significantly reduced incidence of stem-segment colonization by $R.$ $solani$ AG2-2(IV) in Zoysia grass and enhanced growth of grass. Through its biochemical, physiological, and 16S rDNA characteristics, the selected bacterium was identified as $Bacillus$ $subtilis$ subsp. $subtilis$. Mannitol (1%) and soytone (1%) were found to be the best carbon and nitrogen sources, respectively, for use in antibiotic production. An antibiotic compound, designated as DG4, was separated and purified from ethyl acetate extract of the culture broth of isolate C9. On the basis of spectral data, including proton nuclear magneric resonance ($^1H$ NMR), carbon nuclear magneric resonance ($^{13}C$ NMR), and mass analyses, its chemical structure was established as a stereoisomer of acetylbutanediol. Application of the ethyl acetate extract of isolate C9 to several plant pathogens resulted in dose-dependent inhibition. Treatment with the purified compound (an isomer of acetylbuanediol) resulted in significantly inhibited growth of tested pathogens. The cell free culture supernatant of isolate C9 showed a chitinase effect on chitin medium. Results from the present study demonstrated the significant potential of the purified compound from isolate C9 for use as a biocontrol agent as well as a plant growth promoter with the ability to trigger induced systemic resistance of plants.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.11
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• pp.1636-1650
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• 2007

As an initial step toward a better understanding of the genome structure of Korean cattle (Hanwoo breed) and initiation of the framework for genomic research in this bovine, the bacterial artificial chromosome (BAC) end sequencing of 21,024 clones was recently completed. Among these clones, BAC End Sequences (BESs) of 20,158 clones with high quality sequences (Phred score ${\geq}20$, average BES equaled 620 bp and totaled 23,585,814 bp), after editing sequencing results by eliminating vector sequences, were used initially to compare sequence homology with the known bovine chromosomal DNA sequence by using BLASTN analysis. Blast analysis of the BESs against the NCBI Genome database for Bos taurus (Build 2.1) indicated that the BESs from 13,201 clones matched bovine contig sequences with significant blast hits (E<$e^{-40}$), including 7,075 single-end hits and 6,126 paired-end hits. Finally, a total of 5,105 clones of the Korean cattle BAC clones with paired-end hits, including 4,053 clones from the primary analysis and 1,052 clones from the secondary analysis, were mapped to the bovine chromosome with very high accuracy.