• Journal of Periodontal and Implant Science
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• 제29권2호
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• pp.371-387
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• 1999

The present study was performed to assess and compare the clinical and microbiological effects following local application of 2% minocycline gel or 0.1% chlorhexidine subgingival irrigation to augment scaling and root planing in patients with moderate to advanced chronic adult periodontitis. 32 healthy patients with moderate to advanced chronic adult periodontitis were enrolled in the study. In each patient, 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 split-mouth design. All patients received standardized oral hygiene instructions at the beginning of the study and all remaining teeth received scaling and root planing until 0 week. The 2% minocycline gel was applied to periodontal pocket at 0, 1, 2, 3 week in the test side. The 0.1% chlorhexidine solution and the normal saline were irrigated subgingivally for about 30 seconds in the positive control side and negative control side respectively. The clinical and microbiological analysis carried out at 0, 4, 8, and 12 weeks . The results of this study were as follows; 1. In saline irrigation group, there was no adjunctive effects in probing pocket depth reduction, sulcular bleeding index and no significant changes in relative proportions of subgingival bacteria. 2. The chlorhexidine irrigation as an adjunct to scaling and root planing results in reduction in the plaque index and sulcular bleeding index, but there was not statistically significant. The relative proportion of spirochetes was significantly reduced, but the proportion of motile rods was no significant reduction. 3. The minocycline gel delivered subgingivally as an adjunct to scaling and root planing provide significant benefit in reducing probing depths and sulcular bleeding index compared to saline and chlorhexidine irrigation groups. 4. The relative proportions of spirochetes and motile rods were significantly reduced and the proportions of cocci and non-motile bacteria were correspondingly increased in the minocycline gel group. In conclusion, minocycline gel delivered subgingivally as an adjunct to scaling and root planing induces clinical and microbial responses more favorable for periodontal health than saline and chlorhexidine subgingival irrigation.

• International Journal of Industrial Entomology and Biomaterials
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• 제31권2호
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• pp.107-114
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• 2015

Endophytes provide multifarious benefits such as promotion of plant growth and yield, suppression of phyto-pathogens, phosphate solubilising and fixation nitrogen. A study has been carried out to explore growth promotion and antifungal activities of endophytes of mulberry (Morus spp.). Endophytic bacteria were isolated from mulberry plants and studied their cultural, morphological characters, growth promotion as well as their antifungal activity against Rhizoctonia bataticola and Fusarium oxysporum , two mulberry root rot associated pathogens. Except two isolates, all bacteria were colourless and the colony size of eight isolates was small. The margin of five isolates was irregular and the consistency of three isolates was creamy, six isolates was slimy and one was mucoid. Texture of seven isolates was convex and others were flat. Eight isolates were gram positive and the rest Gram negative, five were cocci and others were bacilli (rod shaped). Four isolates were motile and all were catalase positive and only three isolates were oxidase positive. Spore staining was positive only for two isolates. The growth promotion study showed that there was significant difference in root length and seedling length. The antagonistic effect of the bacterial isolates was tested against R. bataticola showed significant (p <0.05) influence of the bacteria, days after inoculation and their interaction on the inhibition of fungal growth. The isolate En-7 completely inhibited the fungus followed by En-5 (66.67%). The bacterial isolates significantly (p <0.05) inhibited growth of F. oxysporum in PDA. The mean inhibition was higher (70.45%) in case of En-7 followed by En-8 (68.65%) and En-10 (66.44%). The study reveals that some endophytic bacteria associated with mulberry have growth promotion and antifungal activity and could be explored for promotion of mulberry growth and managing root rot disease.

• Journal of Plant Biotechnology
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• 제30권2호
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• pp.189-194
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• 2003

Contamination of bacterial infection is one of serious problems in in vitro culture system of root crops. From the contaminated tubes over 140 of petiole cultures of Pinellia ternata, a medicinal plant, 4 genera 8species 48 strains of bacteria, including Aeromonas and Pseudomonas, were isolated and identified and another 8 strains were not fully identified. Most of them were motile Gram positive bacteria as in common in early stage of in vitro cultures. Six strains of bacteria, 5 of Gram negative, including Enterobacter, and 1 of Gram positive, were identified from the embryonic axes cultures of tea plant. From the susceptibility test to pre-screened 5 antibiotics, all of the bacteria except for 2 species of Pseudomonas were susceptible to cefotaxime 60∼100mg/L. While 60mg/L erythromycin only was effective to Pseudomonas. Combination of erythromycin 20mg/L and cefotaxime 60mg/L totally suppressed the growth of all bacterial strains tested. Susceptibility test of bacteria from tea embryonic axes cultures showed similar results. Combination of erythromycin 35mg/L and cefotaxime 60mg/L was effective to 15 bacterial strains and partially effective to 1 unidentified.

• 대한치과의료관리학회지
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• 제6권1호
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• pp.28-35
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• 2018

Halitosis is primarily caused by bacterial decay. The bacteria, which originate from biofilms such as dental plaque, show abnormal proliferation due to dental caries, periodontal diseases, soft tissue infections, and tongue diseases. Most studies on halitosis have exclusively focused on gram-negative bacteria in the oral cavity rather than on general oral microorganisms including oral fungi. This study analyzed oral fungal hyphae, as well as distribution and motility of oral microorganisms, and provided basic data on the control of halitosis. Our results revealed that the greater is the number of cocci bacteria, the higher is the halitosis value, or bad breath value (BBV), suggesting that cocci have a strongly positive correlation with halitosis (r=0.379, p=0.030). Moreover, there was no significant difference in the morphology or distribution of motile bacteria and motility score, with respect to BBV. Lastly, we investigated the relationship between halitosis and oral fungal hyphae. We found that a higher BBV corresponded with a greater number of fungal hyphae and that patients with fungal hyphae scored a higher BBV. However, this result was not statistically significant. In conclusion, this study provided the preliminary data on oral microorganisms and halitosis, but further studies are needed to analyze the relationship between oral microorganisms and halitosis.

• Journal of Periodontal and Implant Science
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• 제28권3호
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• pp.389-401
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• 1998

In this study, 21 patients diagnosed as adult periodontitis were divided into 4 groups. One quadrant with an average of 6mm deep pocket depth was chosen from each individual - Group A inserted tetra-cycline fiber after removing supragingival calculus while group RP had calculus removal and root planning alone. Group RP+A received combination of these treatments while group C received none. Plaque index, bleeding on probing, pocket depth, attachment level, and distribution of subgingival plaque were compared and evaluated among these groups at periods of first visit, 4th week and 8th week. The results were as follows ; 1. Plaque index and bleeding on probing improved after treatment and no significant difference was found between the groups. 2. When comparing the change in pocket depth between the groups, the use of tetracycline fiber showed significant reducton in pocket depth comparable to root planing. Combined therapy of tetracycline fiber and root planing showed synergistic effect in pocket depth reduction. 3. When comparing the change in attachment level between the groups, the use of tetracycline fiber showed significant increase in clinical attachment level comparable to root planing, but no synergistic effect was found in the combined therapy. 4. When comparing the change in the motile bacteria ratio between the groups, group RP and group RP+A showed significant decrease compared with control group. 5. There were no severe adverse effects from using tetracycline fiber, except for a few patient who experienced mild discomfort. In summary, the use of local adminstration of tetracycline fiber in adjunction to mechenical treatment can be effective for adult periodontitis.

• 미생물학회지
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• 제29권1호
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• pp.56-62
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• 1991

Extremely halophilic bacteria isolated from salterns at Mado, Kyunggido, Korea, were identified and investigated on their salt requirements. The results have shown that six strains were identified to be belonged to the genus Halobacterium and three strains identified as the fenus Halococcus. Among them, the optimal NaCl concentration for growth of Halobacterium sp. EH10 was at 4.2M and no growth occurs below 2.0M NaCl. The strain, EH10, is nonmotile and showed acid production from glucose, fructose and maltose while H. salinarum is motile and does not produce acid from any carbohydrates. On the other hand, the strain EH10 does not utilize readily glucose while a number of sugars are readily utilized for growth with acid production by H. saccharovorum. Thus, the isolate, EH10, was classified into the genus Halobacterium and could be a novel species of the genus by its main morphological and physiological features including G+C content. The optimal temperature for growth of the isolate, EH10, was 50.deg.C. But this strain did not grow when NaCl was replaced with KCl.

• Food Science and Biotechnology
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• 제14권4호
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• pp.503-508
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• 2005

Screening for antilisterial activity was performed in about three thousand isolates of lactic acid bacteria (LAB) from Chinese cabbage kimchi, and finally based on the relatively stronger antilisterial activities eight bacterial strains were selected. The bacteria were further characterized in terms of their tolerance to artificial gastric juice, pH 2.5, bile salts (0.3% oxgall), and to the different NaCl concentrations. Of the isolates, YK005 was especially investigated for its physiological characteristics due to its inhibitory activity against gram-positive Listeria monocytogenes as well as gram-negative Escherichia coli O157:H7, as they have been constantly reported to be resistant against bacteriocins produced by a number of LAB strains. YK005 was found to be rod-shaped, $3.8\;{\mu}m$ long ${\times}\;0.5\;{\mu}m$ wide, non-sporeforming, non-motile, catalase-negative, and produced gas from glucose (heterolactic). Based on the biochemical data obtained by API 50 CHL medium, the isolate was tentatively identified as Lactobacillus brevis. To validate the result obtained by the biochemical identification, rRNA-based PCR experiments using a pair of species-specific primers for L. brevis were conducted and a single band of 1400 bp was observed, which strongly indicated that YK005 belongs to L. brevis. The LAB isolates are potentially exploited as human probiotic organisms and are employed to control some food-borne pathogens like L. monocytogenes.

• Journal of Microbiology and Biotechnology
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• 제3권2호
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• pp.108-114
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• 1993

A new strain of acidophilic, acetogenic bacterium, Acetobacter sp. strain HA was isolated by selective enrichment from the traditionally fermented rice wine vinegar in Korea. It was a gram-negative, non-motile short rod and oxidized acetate and lactate. The optimal temperature and pH for growth were $28^{\circ}C$ and 4.0, respectively. The strain HA differed from other Acetobacter species by growing well on methanol, xylitol, inositol, dulcitol, D-xylose, L-arabinose, and D-mannose as sole sources of carbon and energy. The isolated strain HA did not produce $\gamma$-pyrones from glucose and did not produce ketone bodies from glycerol. The quinone system used in this study was an ubiquinone-9 isoprene unit. The guanine-plus-cytosine content of the DNA was 50.7 mol%, and the major cellular fatty acids were $C_{18:1} and C_{16:0}$.

• Preventive Nutrition and Food Science
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• 제3권3호
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• pp.230-233
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• 1998

Acetic acid producing bacteria were isolated from deastringent persimmon vinegar and the major bacterium was identified using morphological and biochemical tests. Acetobacter sp. AH-1 was motile, gram negative rod with catalase positive and oxidase negative. The strain can grow up to 5 % ethanol and 2% NaCl as well as 25% glucose. Optimum temperature and pH for growth were 3$0^{\circ}C$ and 5.0, respectively. Volatile constituents of persimmon vinegar were analyzed by purge and trap sampling . Acetic acid adn alcohol were the largest volatile compounds quantitiatively in persimmon vinegar. Among alcohols, 20methyl-1-propanol, isoamyl alcohol and amyl alcohol were detected. Isovaleradehyde and benzaldehyde for aldehyde, isoamyl acteate, ethyl formate, propyl aceetate, and ethyl acetate for esters were likely to contribute to persimmon vivegar flavor.

• 미생물과산업
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• 제12권2호
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• pp.14-18
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• 1986

Barcterial chemotaxis is a transient response of an organism in a situation where environmental homogeneity has been disturbed by certain chemical compounds. The phenomenon has been described in motile bacterial species including enteric bacteria, Gram-positives(14), Spirochaetes (6) and even Archaebacteria (8). However, most comprehensive studies have been done with Escherichia coli and Salmonella typhimurium. Two analogies to higher eucaryotic sensory phenomena are provided by the study of bacterial chemotaxis. First, bacterial chemotaxis is similar to the stimulus-response of neuronal, immune and sperm cells. Second, studies of individual components involved in the bacterial sensory pathway can contribute to the understanding of the function of receptors, controling signals and molecular comparators in transmembrane signalling system. The bacterial sensory transducer, a chemoreceptor in a broad sense, is a unique entity for studying sensory function in which sensory reception, signalling and adaptation are integrated (7,18).