• Journal of Life Science
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• v.28 no.5
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• pp.627-637
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• 2018

Motility and chemotaxis are crucial for disease development in many motile pathogens, including spirochetes. In many bacteria, motility is provided by flagella rotation, which is controlled by a chemotaxis-signal-transduction system. Thus, motility and chemotaxis are inextricably linked. Spirochetes are a unique group of bacteria with distinctive flat-wave morphology and corkscrew-like locomotion. This unusual motility pattern is believed to be important for efficient motility within the dense tissues through which these spirochetes preferentially disseminate in a host. Unlike other externally flagellated bacteria-where flagella are in the ambient environment-the flagella of spirochetes are enclosed by the outer membrane and thus are called periplasmic flagella or endoflagella. Although motilityand chemotaxis-associated genes are well studied in some bacteria, the knowledge of how the spirochete achieves complex swimming and the roles of most of the putative spirochetal chemotaxis proteins are still elusive. Recently, cutting-edge imaging methods and unique genetic manipulations in spirochetes have helped to unravel the mystery of motility and chemotaxis in spirochetes. These contemporary advances in understanding the motility and chemotaxis of spirochetes in a host's persistence and disease process are highlighted in this review.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.8
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• pp.1251-1257
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• 2005

This study was carried out to investigate characteristics of acetic acid bacteria for persimmon vinegar fermen-tation. Acetic acid bacteria were isolated from statically fermented vinegar. Microscopically the cells appeared as non-motile and non-flagellated, preferentially occuring in pairs. Isolated strains were able to grow in the presence of acetic acid, ethanol, and glucose. Four of them produced 2-ketogluconic acid but did not produce 5-ketogluconic acid. The four strains isolated from statically fermented vinegar were considered to be grouped into Acetobacter. The strains were inoculated into persimmon juice for persimmon vinegar fermentation. They produced acetic acid in the range of 5.25$\∼$5.68$\%$.

• Journal of Periodontal and Implant Science
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• v.28 no.4
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• pp.531-545
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• 1998

The objective of the present study was to evaluate the clinical and microbiological effects of scaling and root planing combined with local application of 2% minocycline gel to patients with moderate to advanced chronic adult periodontitis. 27 healthy patients with moderate to advanced chronic adult periodontitis were enrolled in the study. The quadrants that had 2 or more teeth with $5{\sim}8mm$ probing pocket depth and radiographic evidence of alveolar bone loss were selected and divided into test side and control side according to the splitmouth design. All patients received standardized oral hygiene instructions at the beginning of the study. Subsequently scaling and root plaining was performed on all remaining teeth until 0 week. The 2% minocycline gel was applied to periodontal pocket at 0, 1, 2, 3week in the test side. The normal saline was irrigated subgingivally for about 30 seconds in the control side. The clinical and microbiological analysis was carried out at 0, 4, 8, and 12weeks. The results of this st udy were as follows; 1.2% minocycline gel delivered subgingivally as an adjunct to scaling and root planing provided benefit in reducing sulcular bleeding index and pocket depth than the use of normal saline. 2. The relative proportion of cocci and non-motile bacteria was increased in the test and control groups with time, and there was no statistically significantdifference between two groups. 3. The proportion of spirochetes was slowly reduced in the control group, but, inthe test group, they were remarkably reduced from the 4th week, and there was a statistically significant difference between two groups. 4. In both groups, the relative proportion of motile rods was notably decreasedat the beginning of the study, and remained until 12th week in the test group,but, in the control group, they were slowly increased from the 4th weekand finally similar to that of the initial examination. In conclusion, local application of 2% minocycline gel may be effective in the clinical and microbiological aspects as an adjunct to scaling and root planing in periodontal disease sites.

• Journal of Periodontal and Implant Science
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• v.24 no.2
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• pp.340-356
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• 1994

The purpose of this study was to assess the clinical and microbiological effect of chlorhexidine rinse and supragingival plaque control following scaling and root planing on adult periodontal disease. 14 patients with adult periodontitis were selected for the study . They had not taken antibiotics for 6 months and history of dental treatment for 6 months before the study. Patients received a supragingival scaling and root planing under local anesthesia, plaque control group was subjected to professional plaque control 2 times for a period 2 week, chlorhexidine rinse group were subjected to twice daily 0.2% chlorhexidine rinse for a period 2 week. Clinical examination (plaque index, gingival index, probing pocket depth) and distribution of the bacteria morphology of subgingival plaque were monitored on baseline (0 week), 1 week, 2 week, 4 week and 6 week. The results were as follows : 1. Plaque index in chlorhexidine rinse group , plaque control group and control group was significantly reduced during all weeks (P<0.05). 2. Probing pocket depth was significantly reduced at 2, 4, 6 week (P<0.05) in chlorhexidine rinse group and control group, plaque control group was significantly reduced during all weeks (P<0.05). 3. Gingival index was significantly improved at 2, 4, 6 weeks(P<0.05) in chlorhexidine group and plaque control group, control group was significantly improved at 1, 2, 4 weeks (P<0.05). 4. Percentage of cocci was significantly increased at 1, 2, 4 and 6 weeks in chlorhexidine rinse group and control group, plaque control group was significantly increased at 2, 4 and 6 weeks(P<0.05). 5. Percentage of non-motile rods in all group were not significantly changed when compared with those of baseline (0 week) (P<0.05). 6. Percentage of motile rods was significantly reduced during all weeks (P<0.05) in chlorhexidine rinse group, plaque control group was significantly reduced at 2, 4, 6 weeks and 1, 2 and 4 weeks in control group. 7. Percentage of spirochetes was significantly reduced during all weeks (P<0.05), plaque control group was significantly reduced at 2, 4, 6 weeks and 1, 2, 4 weeks in control group. This results were suggested that clinical and microbiological effect of chlorhexidine rinse and supragingival plaque control following scaling and root planing on periodontal disease

• Journal of Periodontal and Implant Science
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• v.23 no.3
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• pp.411-421
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• 1993

The purpose of this study was to assess the effect of polycaprolactone strip with minocycline on the periodontal pocket in humans and the various clinical parameters in rapidly progressive periodontitis. Nine patients with rapidly progressive periodontitis were selected for the study. They had not taken antibiotics for 6 months and had no history of dental treatment for 6 months before the study. They were in good general health. By the split-mouth method, patients received a supragingival scaling, experimental group (9sites) were subjected to subgingival placement of polycaprolactone strips(1 strip) containg 30% minocyclne and control group (9 site) were subjected to subgingival placement of not polycaprolactone strips(1 strip) containing 30 A Minocycline. Strips were replaced with freshly filled ones at 1 week and 2 week. All strips were removed from pockets at 3 week Clinical examination (plaque index, gingival index, probing pocket depth) and distribution on the bacteria morphology of subgingival plaque were monitored on baseline (0 week), 1, week, 2 week, 4 week and 8 week. The result were as follows : 1. Plaque index in experimental group was not significantly reduced during all weeks(P<0.05), but slightly reduced at 2, 4 and 8 weeks and that in control group was not significantly reduced during monitoring period. 2. Probing pocket depth was significantly reduced at 2, 4 and 8 weeks(P<0.05) in experimental group, but that in control group was not siginificantly changed during monitoring period. 3. Gingival index was significantly improved at 2, 4 and 8 weeks(P<0.05) in experimental group but that in control group was not significantly changed. 4. Percentage of cocci was significantly increased at 2, 4 and 8 weeks in experimental group but that in control group was not significantly changed. 5. Percentage of non-motile rods in both group were not significantly changed when compared with those of baseline(0 week) (P<0.05). 6. Percentage of motile rods was siginificantly reduced at 1, 2 and 4 weeks in experimental group (p<0.05) but that in control group was not significantly changed. 7. Percentage of spirochetes was siginificantly reduced during all weeks(P<0.05) but that in control group was not significantly changed. The result showed that polycaprolactone containing 30% minocycline effect the clinical index and bacterial morphotype.

• Journal of Microbiology and Biotechnology
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• v.31 no.9
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• pp.1210-1217
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• 2021

Two gram-negative, catalase-positive, strictly aerobic, and white colony-forming bacteria, strains H242^T and B156^T, were isolated from soil in South Korea. Cells of strain H242^T were oxidase-positive and non-motile short rods, while those of strain B156^T were oxidase-negative and long non-motile rods. Ubiquinone-8 was identified as the sole isoprenoid quinone in both strains. C_16:0, cyclo-C_17:0, andsummed feature 3 (C_16:1 ω7c and/or C_16:1 ω6c) and phosphatidylethanolamine, phosphatidylglycerol, and diphosphatidylglycerol were identified in both strains as the major cellular fatty acids and polar lipids, respectively. The DNA G+C contents of strains H242^T and B156^T were 69.4 mol% and 69.3 mol%, respectively. Phylogenetic analyses based on 16S rRNA and 92 concatenated core gene sequences revealed that strains H242^T and B156^T formed distinct phylogenic lineages from other Ramlibacter type strains. The DNA-DNA hybridization (DDH) value between strains H242^T and B156^T was 24.6%. Strains H242^T and B156^T were most closely related to Ramlibacter ginsenosidimutans BXN5-27^T and Ramlibacter monticola G-3-2^T with 98.4% and 98.6% 16S rRNA gene sequence similarities, respectively. Digital DDH values between strain H242^T and R. ginsenosidimutans and between strain B156^T and R. monticola were 23.5% and 26.1%, respectively. Phenotypic, chemotaxonomic, and molecular analyses indicated that strains H242^T and B156^T represent two novel species of the genus Ramlibacter, for which the names Ramlibacter terrae sp. nov. and Ramlibacter montanisoli sp. nov., respectively, are proposed. The type strains of R. terrae and R. montanisoli are H242^T (=KACC 21667^T=JCM 33922^T) and B156^T (=KACC 21665^T=JCM 33920^T), respectively.

• Journal of Microbiology and Biotechnology
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• v.30 no.4
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• pp.505-514
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• 2020

The symbiotic nature of the relationship between algae and marine bacteria is well-studied among the complex microbial interactions. The mutual profit between algae and bacteria occurs via nutrient and vitamin exchange. It is necessary to analyze the genome sequence of a bacterium to predict its symbiotic relationships. In this study, the genome of a marine bacterium, Pseudoruegeria sp. M32A2M, isolated from the south-eastern isles (GeoJe-Do) of South Korea, was sequenced and analyzed. A draft genome (91 scaffolds) of 5.5 Mb with a DNA G+C content of 62.4% was obtained. In total, 5,101 features were identified from gene annotation, and 4,927 genes were assigned to functional proteins. We also identified transcription core proteins, RNA polymerase subunits, and sigma factors. In addition, full flagella-related gene clusters involving the flagellar body, motor, regulator, and other accessory compartments were detected even though the genus Pseudoruegeria is known to comprise non-motile bacteria. Examination of annotated KEGG pathways revealed that Pseudoruegeria sp. M32A2M has the metabolic pathways for all seven vitamin Bs, including thiamin (vitamin B1), biotin (vitamin B7), and cobalamin (vitamin B12), which are necessary for symbiosis with vitamin B auxotroph algae. We also identified gene clusters for seven secondary metabolites including ectoine, homoserine lactone, beta-lactone, terpene, lasso peptide, bacteriocin, and non-ribosomal proteins.

• Microbiology and Biotechnology Letters
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• v.30 no.3
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• pp.223-229
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• 2002

For the research of the natural marine antioxidant, several bacteria were isolated from the coast of jin-Hae in Korea. Among the marine bacteria studied, strain HJ-14, a gram-negative, motile, strait rod, aerobic, and $Na^{+}$ required bacterium showed high activity of 1,1-diphenyl-2-picrylhydrazyl radical scav- enging. The morphological, physiological, and biochemical characteristics of the strain HJ-14 were similar to those of the Alteromonas macleodii ATCC $27126^{T}$ . Thus, it was tentatively identified as Alteromonas sp. HJ-14. The compositions of major fatty acids in cell membrane of Alteromonas sp. HJ-14 were $C_{ 14:0}$ , $ C_{15:0}$ , $C_{16:0}$ and $C_{17:1}$ $_{w8c}$ , which also suggest that it is affiliated with Alteromonas sp. The optimum culture conditions for production of antioxidant materials with Alteromonas sp. HJ-14 were at $25$~$37^{\circ}C$ and pH 6~8. The optimum conditions for the production of antioxidant for carbon, inorganic nitrogen, and sodium chloride sources were 2.5%(w/v) dextrin, 0.5%(w/v) ammonium sulfate, and 2~6%(w/v) sodium chloride, respectively. The hydroxyl radical scavenging ability of Alteromonas sp. HJ-14 broth was 90.03%, which is higher than ascor-bic acid(83.28%) and lower than butylated hydroxyanisole(95.46%) and $\alpha$-tocopherol(97.17%).

• Journal of Periodontal and Implant Science
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• v.29 no.1
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• pp.81-93
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• 1999

Non-surgical therapy is still an important technique in periodontal treatment. In this study, scaling and root planing(SRP) with or without concomitant subgingival curettage were compared clinically and microbiologically. 14 moderate adult periodontitis patients were included in this study. After 2 weeks from screening visit, with split mouth design, one quadrant was treated by SRP, and the opposite side was treated by SRP with subgingival curettage. Clinical measurement and microbiological analysis was taken at baseline, 1 month, 3 month post-treatment. Clinical parameters used in this study was probing depth, gingival recession, gingival index, bleeding on probing, plaque index, tooth mobility(Periotest Value). Microbiological analysis consisted of determination of the percentages of 4 bacterial groups according to morphologic type with phase-contrast microscope and measuring Black-pigmented Bacteroides after anaerobic culture. 1. There were significant changes in probing depth and gingival recession at 1 month(P<0.05), and these changes remained through 3 month. However, no significant differences were observed between two groups(P<0.05). 2. There were also significant reductions in gingival index and bleeding on probing at 1 month(P<0.05),and these reduced levels were maintained through 3 month with no significant differences between two groups(P<0.05). 3. In both groups, motile bacteria decreased significantly at 1 months(P<0.05), but increased nearly to baseline level at 3 month. 4. The percentages of Black-pigmented Bacteroides, in both groups, decreased significantly at 1 month(P<0.05), and in the subgingival curettage group, significant more reductions were observed than in the root planing group(P<0.05). At 3 month, significant reduction was found in subgingival curettage group only(P<0.05). According to these results, we surmised that concomitant subgingival curettage and root planing give some advantageous effect on bacterial recolonization.

• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.31-32
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• 2005

Neoagaro-oligosaccharides are produced only by enzymatic degradation of agarose by ${\beta}-agarase.^{1)}$ Neoagaro-oligosaccharides inhibit the growth of bacteria, slow the rate of degradation of starch, are used as low-calorie additives to improve food quality, and have macrophage-stimulating activity. Furthermore, neoagarobiose is a rare reagent that has both moisturizing effect on skin and whitening effect on melanoma $cells.^{2)}$ An agar-degrading marine bacterium was isolated from the sea water at the northeast coast in Cheju island, Korea. The strain was gram negative, aerobic, and motile rod. The 16S rRNA of the strain had the closest match of 98% homology, with that from Agarivorans albus. On the basis of several phenotypic characters and a phylogenetic analysis, this strain was designated Agarivorans sp. JA-1. In solid agar plate, Agarivorans sp. JA-1 produced a diffusible agarase that caused agar softening around the colonies. Agarivorans sp. JA-1 was cultured for 36 hr in marine broth 2216 (Difco, USA) and the supernatant that containing an extracellular ${\beta}-agarase$ was prepared by centrifugation of culture media. The enzyme exhibited relatively strong activity at $40^{\circ}C$ and was stable up to $60^{\circ}C$. Using PCR primers derived from the ${\beta}-agarase$ gene of Vibrio sp., the gene encoding ${\beta}-agarase$ from Agarivorans sp. JA-1 was cloned and sequenced. The structural gene consists of 2931 bp encoding 976 amino acids with a predicted molecular weight of 107,360 Da. The deduced amino acid sequence showed 99% and 34% homology to $agaA^{2)}$ and $agaB^{2)}$ genes for ${\beta}-agarase$ from Vibrio sp., respectively. The expression plasmid for ${\beta}-agarase$ gene of Agarivorans sp. JA-1 is being constructed and the recombinant enzyme will be biochemically characterized.