• Investigative Magnetic Resonance Imaging
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• v.18 no.1
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• pp.70-74
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• 2014

Actinomycosis is caused by filamentous Gram positive anaerobic bacteria from the Actinomycetaceae family, and known as a rare cause of the infection at the eyeball. We report magnetic resonance findings of a 60-year-old Korean man with cervicofacial actinomycosis, including cellulitis in the eye and central nervous system actinomycosis. On orbital magnetic resonance imaging, gadolinium-enhanced T1-weight images showed multiple abnormal enhancing lesions in head and neck including right eye, and some include low signal intensities which considered as abscesses. The lesions was diagnosed as actinomycosis by incisional biopsy, and since then was cured by using antibiotics of penicillin family.

• Proceedings of the Microbiological Society of Korea Conference
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• 2002.10a
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• pp.100-105
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• 2002

The diversity of epiphytic bacterial communities on deciduous oak tree (Quercus dentate Thunb.) leaves was examined both in the natural forest area with a clean air and in the industrial estate to assess effects of acidic deposition to the phyllosphere using 16S rDNA sequence data. In addition, acid-tolerant epiphytic bacterial communities were compared. A total of 78 epiphytic and 444 acid-tolerant clones were obtained from clone libraries, resulting in 20 and 17 phylotypes by analysis of restriction fragment length polymorphism (RFLP) for PCR-amplified 16S rDNA products. A low bacterial diversity in both areas was found. As tree leaves grow older, bacterial diversities were slightly increased in the level of subphylum. The community structure of epiphytic bacteria in both areas in April consisted of only two subphyla, $\beta-and\;\gamma-Proteobacteria$. In August two additional subphyla in both areas were found, but the composition was a little different, Acidobacteria and Cytophaga-Flexibacter-Bacteroids (CFB) group in the industrial estate and a -Proteobacteria and CFB group in the natural area, respectively. Acidobacteria could be an indicator of epiphytic bacteria for acidic deposition on plant leaves, whereas a -Proteobacteria be one of epiphytic bacteria that naturally survive on leaves that are not affected by acidic deposition. The acid-tolerant bacterial communities in April were composed of two subphyla, $\gamma-Proteobacteria$ and Low G+C gram-positive bacteria in both areas, and in August a-Proteobacteria was added to the community just in the natural forest area. The direct influence of acidic deposition on the acid-tolerant bacterial phylogenetic composition could not be detected in higher taxonomic levels such as subphylum, but at narrower or finer levels it could be observed by a detection of Xanthomonadales group of $\gamma-Proteobacteria$ just in the industrial estate.

• Korean Journal of Microbiology
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• v.45 no.1
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• pp.10-16
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• 2009

A diverse range of stresses such as heat, cold, salt, ethanol, oxygen starvation or nutrient starvation induces same stress-responsive proteins. This general stress response enhances bacterial survival significantly. In Bacillus subtilis and closely related Gram-positive bacteria Listeria monocytogenes, the general stress response is controlled by the alternative transcription factor ${\sigma}^B$. The activity of ${\sigma}^B$ is regulated post-translationally by a signal transduction network that has been extensively studied in B. subtilis, and serve as a model for L. monocytogenes. The proposed model of L. monocytogenes signal transduction network is similar to that of B. subtilis, but the energy stress pathway is missing. More than 150 general stress proteins belong to ${\sigma}^B$ regulon of B. subtilis and L. monocytogenes. In both bacteria, ${\sigma}^B$ function is primarily important for resistance to diverse stresses. In addition, ${\sigma}^B$ function contributes to the control of important virulence genes in food-borne pathogen L. monocytogenes. Therefore, understanding of the general stress response is important not only for bacterial physiology, but also for pathogenicity.

• Korean Journal of Microbiology
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• v.50 no.1
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• pp.67-72
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• 2014

Minimal broth containing nicotine as a sole carbon source (MB/N) was used to isolate novel nicotine-degrading bacterial strains from tobacco plants and field soils. Comparative analysis of 16S rRNA gene sequence, phenotypic test and morphological tests showed that the position of these isolates were in the genus Arthrobacter of the family Micrococcaceae. The highest 16S rRNA gene sequence similarity of the isolate NU11 and NU15 to type strains in the genus Arthrobacter were Arthrobacter equi (98.2%) which was presumably a novel strain and Arthrobacter nicotinovorans (99.8%), respectively. Both strain NU11 and NU15 showed rod shaped, Gram-positive characteristics and catalase activity, but did not show oxidase activity. The novel strain NU11 was found to degrade efficiently nicotine in MB/N medium by the analysis of UV absorption spectra and could be used as an organism in bioremediation technique.

• KSBB Journal
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• v.31 no.3
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• pp.158-164
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• 2016

Plant growth promoting (PGP) hormones, which are produced in a small quantity by bacteria, affect in plant growth and development. PGPs play an important role on the crop productivity in agricultural field. In this study, a photosynthetic bacterial strain producing the PGP was isolated from paddy soil. Bacterial isolate was gram negative, rod-shaped and motility positive. From the 16s rRNA gene sequence analysis, the isolate was identified as Rhodobacter capsulatus PS-2. The mass cultivation of R. capsulatus PS-2 was optimized by considering of the carbon, nitrogen and inorganic salt sources. Optimal medium composition was determined as Na-succinate 4.5 g, yeast extract 5 g, $K_2HPO_4$ 1 g, $MgSO_4$ 5 g, per liter. From the result of 500 L fermentation for 2 days using the optimal medium, the viable cells were $8.7{\times}10^9cfu/mL$. R. capsulatus PS-2 strain produced the carotenoid and indole-3-acetic acid (IAA). The carotenoid extraction and quantitative analysis were performed by HCl-assisting method. Total carotenoid contents from R. capsulatus PS-2 culture broth were measured as $7.02{\pm}0.04$ and $6.93{\pm}0.05mg/L$ under photoheterotrophic and chemoheterotrophic conditions, respectively. To measure the productivity of IAA, colorimetric method was employed using Salkowski reagent at optical density 535 nm. The results showed that the highest content of IAA was $197.44{\pm}5.92mg/L$ in the optimal medium supplemented with 0.3% tryptophan.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.6
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• pp.642-647
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• 2010

This study examined the antimicrobial activity of Myagropsis yendoi (MY). The antimicrobial activity of ethanol and aqueous MY extracts were measured using a paper disc assay. The MY ethanol extract had the best antimicrobial activity. It inhibited the growth of Candida tropicalis and Gram-positive bacteria such as Bacillus subtilis, Listeria innocua, L. monocytogenes, and Staphylococcus aureus at 4 mg/mL. The minimum inhibitory concentration (MIC) of the MY ethanol extract ranged from 0.1 to 0.5%. The MY ethanol extract inhibited the growth of B. subtilis and L. innocuaat concentrations of 0.15% and 0.1%, respectively. The antimicrobial activity of the MY ethanol extract was not affected by heating at $121^{\circ}C$ for 15 min or pH 2.10. Therefore, the main substances responsible for the antimicrobial activity of the MY ethanol extract are believed to be stable with changing heat and pH.

• Journal of Microbiology and Biotechnology
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• v.26 no.12
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• pp.2106-2115
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• 2016

To identify the global effects of (p)ppGpp in the gram-positive bacterium Deinococcus radiodurans, which exhibits remarkable resistance to radiation and other stresses, RelA/SpoT homolog (RSHs) mutants were constructed by direct deletion mutagenesis. The results showed that RelA has both synthesis and hydrolysis domains of (p)ppGpp, whereas RelQ only synthesizes (p)ppGpp in D. radiodurans. The growth assay for mutants and complementation analysis revealed that deletion of relA and relQ sensitized the cells to $H_2O_2$, heat shock, and amino acid limitation. Comparative proteomic analysis revealed that the bifunctional RelA is involved in DNA repair, molecular chaperone functions, transcription, the tricarboxylic acid cycle, and metabolism, suggesting that relA maintains the cellular (p)ppGpp levels and plays a crucial role in oxidative resistance in D. radiodurans. The D. radiodurans relA and relQ genes are responsible for (p)ppGpp synthesis/hydrolysis and (p)ppGpp hydrolysis, respectively. (p)ppGpp integrates a general stress response with a targeted re-programming of gene regulation to allow bacteria to respond appropriately towards heat shock, oxidative stress, and starvation. This is the first identification of RelA and RelQ involvement in response to oxidative, heat shock, and starvation stresses in D. radiodurans, which further elucidates the remarkable resistance of this bacterium to stresses.

• Journal of Crop Science and Biotechnology
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• v.10 no.3
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• pp.167-174
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• 2007

Spongy Alphonso mangoes were found to be infected with Staphylococcus bacteria. A Gram positive Staphylococcus strain was isolated from spongy pulp and identified from CABI Bioscience, UK, by partial 16S rDNA sequence analysis and by morphological and biochemical characterization through IMTECH, Chandigarh, India. Although identification by both of these methods indicated the organism belonged to same genus, different species names were given. Changes in total phenolics, reducing, and non-reducing sugars, respiration rate, total carotenoids, peroxidase(POX), and catalase activities were monitored during ripening of these fruits. The climacteric rise in spongy fruits was marked by an increase in respiration rate and a decrease in sugar content. Total phenolics content increased in spongy fruits as compared to ripe non-spongy fruits. Development of corky white tissue in spongy fruits was associated with about a 2.5-fold reduction in total carotenoids and a concomitant increase in lipoxygenase-mediated, $\beta$-carotene co-oxidation. A marked decrease in soluble protein content and about a 1.5-fold increase in POX activity was observed. Maximum POX activity was confined to 50-70%$(NH_4)_2SO_4$ fraction. The intense dark bands visible after POX specific substrate staining of the Native gel indicated a high expression of isoenzymes of POX in spongy fruits. Similarly, changes in levels of catalase activity were also observed in spongy fruits. The results suggest that infection of Alphonso mangoes with Staphylococcus bacteria affects the normal ripening processes of the fruit interfering with the carbohydrate and carotenoid metabolism. Also, the studies indicate the expression of POX and catalase enzymes as a plant defense response to microbial invasion.

• Journal of Korean society of Dental Hygiene
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• v.17 no.3
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• pp.493-504
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• 2017

Objectives: This study aimed to find out the antimicrobial activities of Ramaria botrytis (Fr.) extracts against oral pathogens. Methods: The antimicrobial activities of Ramaria botrytis (Fr.) extracts were evaluated against oral pathogens by the disc diffusion assay, and the minimum inhibitory concentrations (MICs) of ethyl acetate extracts were determined by broth dilution method. The strains used in this study were Staphylococcus aureus, Streptococcus mutans, Streptococcus sanguinis, Streptococcus sobrinus, Streptococcus anginosus, Streptococcus ratti, Streptococcus criceti, Actinomyces israelii, Actinomyces viscosus and Aggregatibacter actinomycetemcomitans. Results: The ethyl acetate extract of Ramaria botrytis (Fr.) effectively inhibited the growth of oral bacteria compared with acetone or ethanol extract. The ethyl acetate extract exhibited MIC values ranging from 3.75 to 15.00 mg/ml, and it showed antimicrobial activity against both Gram-positive and negative oral bacteria. Conclusions: The ethyl acetate extracts from Ramaria botrytis (Fr.) showed the antimicrobial activities against ten oral bacteria. Thus, the extract of Ramaria botrytis (Fr.) may be considered as an effective natural antimicrobial agent for the prevention of oral pathogens.

• Journal of the Korea Organic Resources Recycling Association
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• v.3 no.1
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• pp.21-34
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• 1995

For development of microbial additives applicable to in-vessel composting system of food waste, thermophilic bacteria which showed amylase, protease, lipase and cellulase activity were isolated from soil, compost and food waste. Among 81 isolates, the growth characteristic of 20 strains with high enzyme activity were examined. All strains are Gram positive rod with catalase activity and 17 strains are spore formers. At $50^{\circ}C$, most of the strains were able to grow from pH 5 to pH 10 and in presence of 8% of NaCl. In trypticase soy broth, the growth of these strains was greatly increased by aeration, but decreased at elevated temperature above $50^{\circ}C$.