• Journal of Life Science
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• v.12 no.5
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• pp.566-569
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• 2002

Acetobacter strains are bacteria that can synthesize cellulose when grown on an undefined medium containing glucose. Several culture conditions affecting cellulose production by Acetobacter sp. A9 were examined by cultivating cells under shaking cultures. The addition of buffering agents, such as 3-(N-morpholino) propanesulfonic acid (MOPS) and CaCO$_3$, increased cellulose production. It suggests that pH of culture medium is important to an economical mass cellulose production. Addition of bead (Ф10 w) to culture medium stimulated 'disintegrated bacterial cellulose' production.

• Plant Disease and Agriculture
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• v.1 no.1
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• pp.19-29
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• 1995

A microbial product composed of three antagonistic fungal isolates (Aspergillus sp., Penicillium sp. and Trichoderma sp.) and three bacterial isolates (Arthrobacter sp., Bacillus sp., and Pseudomonas sp.) was tested for the control of Pythium blight caused by Pythium sp., brown patch by Rhizoctonia solani (anastomosis group(AG) 1-1) and large patch by R. solani (AG 2-2) of turfgrasses. Cultures of the antagonistic fungi and bacteria varied in the effectiveness in reducing disease severity of Pytium blight and brown patch on bentgrass. The antagonistic fungal and bacterial isolates were mixed and cultured at 20-$25^{\circ}C$ for 3 days in a growth medium, and the diluted solution of the microbial culture was applied under the field conditions after inoculation of the above turfgrass pathogens. The treated turfgrass was incubated at 28$^{\circ}C$ in a growth chamber. In this experiment, Pythium blight was almost completely controlled and brown patch was slightly decreased by the microbial product, while no control was observed in large patch of zoysiagrass. In zoysiagrass treated with the microbial culture, thatch accumulation was notably reduced.

• Korean Journal of Microbiology
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• v.42 no.4
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• pp.286-293
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• 2006

Three hundred thirty two bacterial colonies which were able to degrade crude oil were isolated from soil samples that were contaminated with oil in Daejon area. Among them, one bacterial strain was selected for this study based on its low surface tension ability, and this selected bacterial strain was identified as Pseudomonas sp. G314 through physiological-biochemical tests and analysis of its 16S rRNA sequence. Pseudomonas sp. G314 showed a high resistance to antibiotics such as ampicillin, chloramphenicol, spectinomycin, and streptomycin, and heavy metals such as Li, Cr, and Mn. It was found that the optimal pH and temperature for biosurfactant production of Pseudomonas sp. G314 were pH 7.0 and $30^{\circ}C$, respectively. After seven hours of inoculated, the biosurfactant activity reached the maximum, and surface tension of the culture broth was decreased from 72 to 25 dyne/cm. The crude biosurfactant was obtained from the culture broth by acid precipitation, followed by solvent extraction, evaporation and then freeze drying. The CMC (critical micelle concentration) value of the crude biosurfactant was 20 mg/L.

• Journal of Microbiology and Biotechnology
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• v.20 no.8
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• pp.1230-1239
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• 2010

Five bacterial species, capable of degrading the recalcitrant organic compounds (ROCs) diethyleneglycol monomethylether (DGMME), 1-amino-2-propanol (APOL), 1-methyl-2-pyrrolidinone (NMP), diethyleneglycol monoethylether (DGMEE), tetraethyleneglycol (TEG), and tetrahydrothiophene 1,1-dioxide (sulfolane), were isolated from an enrichment culture. Cupriavidus sp. catabolized $93.5{\pm}1.7$ mg/l of TEG, $99.3{\pm}1.2$ mg/l of DGMME, $96.1{\pm}1.6$ mg/l of APOL, and $99.5{\pm}0.5$ mg/l of NMP in 3 days. Acineobacter sp. catabolized 100 mg/l of DGMME, $99.9{\pm}0.1$ mg/l of NMP, and 100 mg/l of DGMEE in 3 days. Pseudomonas sp.3 catabolized $95.7{\pm}1.2$ mg/l of APOL and $99.8{\pm}0.3$ mg/l of NMP. Paracoccus sp. catabolized $98.3{\pm}0.6$ mg/l of DGMME and $98.3{\pm}1.0$ mg/l of DGMEE in 3 days. A maximum $43{\pm}2.0$ mg/l of sulfolane was catabolized by Paracoccus sp. in 3 days. When a mixed culture composed of the five bacterial species was applied to real wastewater containing DGMME, APOL, NMP, DGMEE, or TEG, 92~99% of each individual ROC was catabolized within 3 days. However, at least 9 days were required for the complete mineralization of sulfolane. Bacterial community diversity, analyzed on the basis of the TGGE pattern of 16S rDNA extracted from viable cells, was found to be significantly reduced in a conventional bioreactor after 6 days of incubation. However, biodiversity was maintained after 12 days of incubation in an electrochemical bioreactor. In conclusion, the electrochemical reduction reaction enhanced the diversity of the bacterial community and actively catabolized sulfolane.

• Journal of Microbiology and Biotechnology
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• v.31 no.9
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• pp.1241-1255
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• 2021

This study was carried out to explore a non-chemical strategy for enhancing productivity by employing some antagonistic rhizobacteria. One hundred eighteen bacterial isolates were obtained from the rhizospheric zone of various crop fields of Gangwon-do, Korea, and screened for antifungal activity against Fusarium wilt (Fusarium oxysporum f. sp. lactucae) in lettuce crop under in vitro and in vivo conditions. In broth-based dual culture assay, fourteen bacterial isolates showed significant inhibition of mycelial growth of F. oxysporium f. sp. lactucae. All of the antagonistic isolates were further characterized for the antagonistic traits under in vitro conditions. The isolates were identified on the basis of biochemical characteristics and confirmed at their species level by 16S rRNA gene sequencing analysis. Arthrobacter sulfonivorans, Bacillus siamensis, Bacillus amyloliquefaciens, Pseudomonas proteolytica, four Paenibacillus peoriae strains, and Bacillus subtilis were identified from the biochemical characterization and 16S rRNA gene sequencing analysis. The isolates EN21 and EN23 showed significant decrease in disease severity on lettuce compared to infected control and other bacterial treatments under greenhouse conditions. Two bacterial isolates, EN4 and EN21, were evaluated to assess their disease reduction and growth promotion in lettuce in field conditions. The consortium of EN4 and EN21 showed significant enhancement of growth on lettuce by suppressing disease caused by F. oxysporum f. sp. lactucae respectively. This study clearly indicates that the promising isolates, EN4 (P. proteolytica) and EN21 (Bacillus siamensis), can be commercialized and used as biofertilizer and/or biopesticide for sustainable crop production.

• International Journal of Industrial Entomology and Biomaterials
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• v.18 no.1
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• pp.49-52
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• 2009

An in vitro and in vivo studies were conducted to evaluate the antibacterial efficacy of certain botanicals viz., rhizomes of turmeric (Curcuma longa) and leaves of amla (Phyllanthus emblica), asparagus (Asparagus racemosus), bael (Aegle marmelos), boerhavia (Boerhavia diffusa), garlic (Allium sativum) and basil (Oscimum basicilum) against bacterial pathogens viz., Staphylococcus sp., Bacillus sp. and Klebsiella cloacae, of silkworm, Bombyx mori. Asparagus and basil, amla and boerhavia, basil and bael at concentration of 20, 000 ppm showed higher antibacterial activity against Staphylococcus sp., Bacillus sp., K. cloacae respectively, both in vitro and in vivo studies.

• Journal of Life Science
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• v.15 no.1 s.68
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• pp.94-99
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• 2005

Sixty four bacterial colonies which were able to oxidize the manganese were isolated from soil samples in Mokcheon and Ochang area. Among them, one bacterial strain was selected for this study based on its higher manganese oxidation, and this selected bacterial strain was identified as Aeromonas sp. MN44 through physiological-biochemical test and analysis of its 16s rRNA sequence. Aeromonas sp. MN44 was able to utilize lactose but did not utilize various carbohydrates as a sole carbon source. Aeromonas sp. MN44 showed a very sensitive to antibiotics such as kanamycin, chloramphenicol, ampicillin, tetracycline and spectinomycin, and heavy metal such as cadmium. But this strain showed a high resistance up to mg/ml unit to heavy metals such as lithium and manganese. Optimal manganese oxidation condition of Aeromonas sp. MN44 was pH 7.4 and manganese oxidation activity was inhibited by proteinase K and boiling treatment. So, we concluded that this factor was protein. The manganese oxidizing factor produced by Aeromonas sp. MN44 was partial purified by ammonium sulfate precipitation, DEAE-Toyopearl 650M ion exchange chromatography and Sephadex gel filtration chromatography. Its molecular mass was about 113 kDa.

• Korean Journal of Organic Agriculture
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• v.14 no.4
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• pp.399-410
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• 2006

This study was carried out to identity the effects of antifungal bacteria isolated from the soil grown kiwi fruit plants on the growth inhibition of Botrytis cinerea causing gray mold in kiwi fruit plants in the southern districts of Jeonnam. Two hundred and fifty antagonistic microorganisms were isolated and examined into the antifungal activity against Botrytis cinerea. We screened and isolated four bacterial strains which strongly inhibited Botrytis cinerea from the soil grown kiwi fruit plants. And the best antifungal bacterial strain which called CHO 163 was finally selected. Antagonistic microorganism CHO 163 was identified to be the genus Bacillus sp. based on the morphological and biochemical characterization. Bacillus sp. CHO 163 showed 86.9% of antifungal activity against Botrytis cinerea. By the bacterialization of culture broth and heated filtrates of culture broth, Bacillus sp. CHO 163 showed almost all of antagonistic activity against Botrytis cinerea. And we also confirmed that in vitro the treatment of Bacillus sp. CHO 163 cultured by SD+B+P broth efficiently controled the growth of Botrytis cinerea causing gray mold in kiwi fruit plants.

• Journal of Life Science
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• v.21 no.1
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• pp.134-140
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• 2011

One hundred forty five bacterial colonies which were able to degrade crude oil were isolated from soil samples that were contaminated with oil in the Daejon area. Among these colonies, one bacterial strain was selected for this study based on its low surface tension ability, and this selected bacterial strain was identified as Pseudomonas sp. Z1 through physiological-biochemical tests and analysis of its 16S rRNA sequence. Pseudomonas sp. Z1 showed a high resistance to antibiotics such as chloramphenicol and ampicillin, as well as heavy metals such as lithium, manganese, and barium. It was found that the optimal pH and temperature for biosurfactant production of Pseudomonas sp Z1 were pH 6.0-7.0 and $30^{\circ}C$, respectively. After ten hours of inoculation, the biosurfactant activity of the culture broth decreased rapidly, and had maximum surface tension (28 dyne/cm) after twenty-one hours incubation. The biosurfactant activity of the culture broth was also decreased up to 2% NaCl concentration.

• Journal of Korean Ophthalmic Optics Society
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• v.18 no.1
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• pp.67-73
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• 2013

Purpose: Recently, bacterial contamination of equipment and accessories required for vision correction has become a main causal factor in ophthalmic diseases. Thus, We investigated on both the actual condition of bacterial contamination from glasses of vision correction. Methods: Investigation of microorganisms was carried out with a group of 145 glasses wearers, composed of 36 elementary school students, 37 middle school students, 38 high school students, 10 college students, and 32 aged men. Results: Seventeen species of bacteria are detected from glasses of vision correction: B. cereus, B. licheniformis, Bacillus sp., CNS, Enterococcus sp., Escherichia coli, Proteus sp., Pseudomonas sp., Serretia sp., Streptococcus sp., Staphylococcus epidermidis, Staphylococcus aureus, Streptococcus hemolyticus,, Acinetobacter sp., Enterobacter cloacae, GNR, and Pseudomonas aeruginosa. Among 17 species of bacteria, there are some potential causative agents for keratitis, corneal ulcer, Acute dacryocystitis, Orbital cellulitis, Periphlebitis retinae, Marginal blepharitis, and Acute conjunctivitis. Enterobacter cloacae, Pseudomonas aeruginosa and Staphylococcus epidermidis cause keratitis. Pseudomonas sp., and Staphylococcus aureus cause corneal ulcer. Staphylococcus aureus causes acute dacryocystitis, orbital cellulitis, periphlebitis retinae, marginal belpharitis. Streptococcus hemolyticus causes acute conjunctivitis. Conclusions: In summation, it is verified that hazardous, opportunistic and infectious microorganisms exist in glasses for vision correction. Ophthalmic diseases are predicted. Therefore, supplementary research on the development of a cleaning solution to cleanse the infection and of an effective method to remove microorganisms is required.