• Mycobiology
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• v.36 no.4
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• pp.260-265
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• 2008

Cyclic voltammetric measurements were performed for Co(II), Ni(II), Cu(II) and Zn(II) complexes of 1 : 1 alternating copolymer, poly(3-nitrobenzylidene-1-naphthylamine-co-succinic anhydride) (L) and Ni(II) and Cu(II) complexes of 1 : 1 alternating copolymer, poly(3-nitrobenzylidene-1-naphthylamine-co-methacrylic acid) ($L^1$). The in vitro biological screening effects of the investigated compounds were tested against the fungal species including Aspergillus niger, Rhizopus stolonifer, Aspergillus flavus, Rhizoctonia bataicola and Candida albicans and bacterial species including Staphylococcus aureus, Escherichia coli, Klebsiella pneumaniae, Proteus vulgaris and Pseudomonas aeruginosa by well diffusion method. A comparative study of inhibition values of the copolymers and their complexes indicates that the complexes exhibit higher antimicrobial activity. Copper ions are proven to be essential for the growth-inhibitor effect. The extent of inhibition appeared to be strongly dependent on the initial cell density and on the growth medium. The nuclease activity of the above metal complexes were assessed by gel electrophoresis assay and the results show that the copper complexes can cleave pUC18 DNA effectively in presence of hydrogen peroxide compared to other metal complexes. The degradation experiments using Rhodamine B dye indicate that the hydroxyl radical species are involved in the DNA cleavage reactions.

• Restorative Dentistry and Endodontics
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• v.14 no.1
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• pp.85-96
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• 1989

In the Infected root canals, the majority of the isolated bacteria are either strict anaerobes or microaerophilic organisms. Among thease, Black-pigmented Bacteroides species are the most important and have relation with clinical symptoms. The purpose of this study were to investigate on the 7 different types of bacteria which include Black-pigmented Bacteroides - Black--pigmented Bacteroides, Actinobacillus actinomycetemcomitans, Streptococcus, Capnocytophaga, Eiknella corrodens, Fusobacterium, Actinomyces - and the interrelationship between these 7 bacterical species, and to compare Black-pigmented Bacteroides with the clinical symptoms in infected root canals. The canal contents of 15 necrotized teeth with 8 clinical symptoms were sampled and cultured aerobically and anaerobically for growth in 7 selective agar plates for 7 bacterial species. Black-pigmented Bacteroides and Streptococcus subspecies were identified by biochemical tests. The results were as follows; 1. 70.51% of the bacteria isolated were anaerobes and 29.49% were aerobes. 2. B. loescheii, B. intermedius, B. denticola were isolated in 8 cases, Streptococcus was isolated in 8 cases, Fusobacterium was isolated in 6 cases, Actinomyces was isolated in 5 cases and Eiknella corrodens, Actinobacillus actinomycetemcomitans, Capnocytophaga were not isolated. 3. There were mutual inhibition of growth between Black-pigmented Bacteroides and Streptococcus. (P<0.01) But Actinomyces and Fusobacterium showed mutual aids for growth. (P<0.05) 4. Black-Pigmented Bacteroides was found to be related both to sinus tract formation and to apical sensitivity to palpation.(P < 0.05).

• Journal of Microbiology and Biotechnology
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• v.14 no.2
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• pp.312-316
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• 2004

Five strains, producing bacterial thermostable L-arabinose isomerase, were isolated from Korean soil samples obtained from compost under high temperature circumstances. Among these strains, the CBG-Al showed the highest L-arabinose isomerase activity at $60^\circ{C}$ and was selected as a D-tagatose producing strain from D-galactose. This strain was identified as Geobacillus thermodenitrificans based on the 16S rRNA analysis, and biological and biochemical characteristics. The isolated strain was aerobic, rod-shaped, Gram-positive, nonmotile, and an endospore-forming bacterium. No growth was detected in culture temperature below $40^\circ{C}$. The maximum growth temperature and maximum temperature of enzyme activity were $75^\circ{C}$ and $65^\circ{C}$, respectively. In metal ion effects, $Ca^{2+}$ was the most effective enzyme activator with the reaction rate by 150%. In a 5-1 jar fermentor with 3-1 MY medium, L-arabinose isomerase activity was growth-associated and pH decreased rapidly after the initial logarithmic phase.

• Food Science of Animal Resources
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• v.30 no.6
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• pp.946-950
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• 2010

This study evaluated the antimicrobial effects of meat processing-related organic acids on Burkholderia thailandensis (Burkholderia pseudomallei surrogate) with different water activities. B. thailandensis KACC12027 (4 log CFU/mL) was inoculated in microwell plates containing tryptic soy broth pH-adjusted to 4, 5, 6, and 7 with ascorbic acid, citric acid, and lactic acid and with water activities adjusted to 0.94, 0.96, 0.98, and 1.0 with NaCl, followed by incubation at $35^{\circ}C$ for 30 h. The optical density (OD) of the samples was measured at 0, 3, 6, 12, 24, and 30 h at 595 nm to estimate the growth of B. thailandensis. Growth of B. thailandensis was observed only at water activity of 1.0. In general, more bacterial growth (p<0.05) was observed at pH 6 than at pH 7, and the antimicrobial effects of the organic acids on B. thailandensis were in the following order: Ascorbic acid > lactic acid > citric acid after incubation at $35^{\circ}C$ for 30 h. These results indicate that organic acids in meat processing-related formulations should be useful in decreasing the risk related to an emerging high risk agent (B. pseudomallei).

• Journal of Microbiology and Biotechnology
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• v.15 no.2
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• pp.337-345
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• 2005

The degradation of phenanthrene, a model PAH compound, by microorganisms either in the mixed culture or individual strain, isolated from oil-contaminated soil in oil refmery vicinity sites, was examined. The effects of pH, temperature, initial concentration of phenanthrene, and the addition of carbon sources on biodegradation potential were also investigated. Results showed that soil samples collected from four oil refinery sites in Korea had different degrees of PAH contamination and different indigenous phenanthrene-degrading microorganisms. The optimal conditions for phenanthrene biodegradation were determined to be 30$^{circ}C$ and pH 7.0. A significantly positive relationship was observed between the microbial growth and the rate of phenanthrene degradation. However, the phenanthrene biodegradation capability of the mixed culture was not related to the degree of PAH contamination in soil. In low phenanthrene concentration, the growth and biodegradation rates of the mixed cultures did not increase over those of the individual strain, especially IC10. High concentration of phenanthrene inhibited the growth of microbial strains and biodegradation of phenanthrene, but was less inhibitory on the mixed culture. Finally, when non-ionic surfactants such as Brij 30 and Brij 35 were present at the level above critical micelle concentrations (CMCs), phenanthrene degradation was completely inhibited and delayed by the addition of Triton X100 and Triton N101.

• Proceedings of the Turfgrass Society of Korea Conference
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• 2011.02a
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• pp.35-35
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• 2011

A large patch disease caused by Rhizoctonia solani AG2-2(IV) is a serious problem in turfgrass sites including golf courses and sports fields in Korea. The objectives of this study were to isolate some antagonistic microorganisms and to explain some involving mechanisms. Initially single colonies which were formed from the filtrates of various soil samples were obtained from LB culture and then co-cultured with R.solani AG2-2(IV) on PDA plate to explore some antagonistic microbes against for large patch fungus, Rhizoctonia solani AG2-2(IV). Out of total 82 antagonistic isolates which commonly had inhibition effect on Rhizoctonia solani AG2-2(IV) mycelial growth, one candidate (YPIN22) showed the most antifungal effect, which was confirmed by the longest distance from the edge of bacterial colony to the mycelial edge of the Rhizoctonia solani AG2-2(IV) in the dual culture. A succeeding investigation was to test any potential effect of the isolate on growth inhibition of 5 other turfgrass pathogens including R. solani solani AG2-2(IIIB), P. ultimum, C. caudatum, C. lunata, and F.oxysporum. Preliminary result indicated that the new isolate YPIN22 was also found to have antagonistic potential on the growth inhibition of those turfgrass pathogenic fungi, which was explained by inhibition zones ranging from 8 to 22mm. A further explanation of some characteristics of the isolate YPIN22 will be discussed in detail.

• Food Science and Preservation
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• v.7 no.1
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• pp.124-131
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• 2000

Antibacterial activities of powdered spices(garlic , ginger, cinnamon and clove) against pathogenic Escherichia coli )157:H7 and Staphyloccus auresus were investigated. Spice powder was added in was exponetial phase of each bacterial culture . Growth inhibition was determined by the absorbance at 660nm and morphological changes of the cells were observed by transmission electron microscope (TEM). Ginger powder has the highest antibacterial activity, following cinnamon , clove and garlic has the least activity.Growth of Escherichia coli O157:H7 and Staphyloccus aureus were completely inhibited within 5 hours after addition of 1 % of garlic , 0.3% of ginger or cinnamon , 0.5% of clove powder on the exponential phase of the cells. Spice untreated cells of E. coli and S. aureus, the cytoplasm was entirely surrounded by rigid cell wall and cell walls formed a smooth layer well attached to the plasma membrane. In the cells of E. coli and S. aureus treated with spice powder, cell wall and plasma membrane were lysed and severely damaged. E.coli cells growth in the presence of spice powder showed plammolysis, the loss of electron dense material, the formation of extra cellular blebs and cytoplasm burst out from the cell. S .sureus cells grown in the presence of spice powder showed swell of cell wall, the loss of electron dense material , coagulation of cell cytoplasm and formation of extra cellular blebs. Severely damaged cells of S. aureus lost whole cytoplasm and left as ghost of the cell. Spice powder stimulated autolyssi and induced cell death.

• Microbiology and Biotechnology Letters
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• v.16 no.2
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• pp.85-91
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• 1988

Energy efficiency of bacterial cell mass and product formation from cellulose using Ruminococcus albus and Ruminococcus flavefaciens with application of available electron balance were discussed. Values of true growth yield, η$_{max}$ and η$^{max}_{th}$ and maintenance coefficient, m$_{e}$, were estimated us-ing experimental data, and the results were compared with estimates obtained from theoretical ap-proach. Experimental values were similar in magnitude to theoretical values in $Y^{max}_{ATP}$= 10.5 g cells/ mole ATP. Therefore, $Y^{max}_{ATP}$ values of Ruminococcus albus and Ruminocoecus flavefaciens were considered similar to 10.5 g cells/mole ATP.

• Korean Journal of Veterinary Service
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• v.37 no.1
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• pp.35-43
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• 2014

Salmonellosis has caused heavy losses in swine industry and implications for public health. Recently, the urgent problem of antibiotic resistance due to multidrug-resistant Salmonella spp. has been on the rise. The use of host-specific bateriophages as a biocontrol is one possible alternative. In this study, clinical signs, growth performance, quantification and detection of antigen, histopathological changes of gastrointestinal tracts were analyzed comparatively in weaned piglets according to administration of bacteriophages and challenge with Salmonella (S.) Typhimurium. Piglets challenged with S. Typhimurium after administered with bacteriophages showed reduced clinical signs, higher growth performance, lower bacterial shedding, lower quantificational value of antigens in intestines, higher V/C ratio and higher the number of goblet cells in intestines than piglets administered without bacteriophage and challenged with S. Typhimurium. These results indicate that feeding contained with bacteriophages has effect to prevent infection of S. Typhimurium in weaned piglets and suggest that a use of bacteriophage can be considered a valid antibiotic alternative.

• Biomedical Science Letters
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• v.24 no.3
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• pp.270-274
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• 2018

Chlorine dioxide ($ClO_2$) gas is a neutral chlorine compound. $ClO_2$ gas was proven to effectively decontaminate different environments, such as hospital rooms, ambulances, biosafety level 3 laboratories, and cafeterias. In this study, to evaluate the effects of $ClO_2$ gas, bacteria of clinical importance were applied. Staphylococci, Streptococci and Bacillus strains were applied and Klebsiella, and others e.g., Escherichia coli, Shigella, Salmonella, Serratia were also done for the inhibitory analysis. Bacteria plates were applied with a hygiene stick, namely, "FarmeTok (Medistick/Puristic)" to produce $ClO_2$. $ClO_2$-releasing hygiene stick showed the very strong inhibition of bacterial growth but had different inhibitions to the bacteria above 96.7% except for MRSA of 90% inhibition. It is difficult to explain why the MRSA were not inhibited less than others at this point. It can be only suggested that more releasing $ClO_2$ should be essential to kill or inhibit the MRSA. B. subtilis, S. agalactiae, S. pyogenes, E. coli O157:H7, S. typhi (S. enterica serotype typhi) and S. marcesence were inhibited over 99%. This study will provide fundamental data to research growth inhibition by $ClO_2$ gas with bacteria of clinical importance value.