• Korean Journal of Microbiology
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• v.50 no.2
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• pp.164-168
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• 2014

The ecosystem of the Arctic region has been increasingly affected by global warming. Archaeal ammonia monooxygenase alpha subunit coding gene (amoA) which is a key enzyme for nitrification was used to investigate the effect of runoff water of ice melt on microbial community of nitrogen cycle. The archaeal amoA genes at coastal area of Svalbard, Arctic region were PCR-amplified and sequenced after clone library construction. Analysis of archaeal amoA gene clone libraries suggested that the station 188 which is in the vicinity to the area of runoff water harbor lower ammonia-oxidizing archaeal diversity than the station 176 and 184. The average amino acid sequence identity within all archaeal amoA gene clones was 94% (with 91% nucleotide sequence identity). While all the clones of the station 188 were affiliated with Nitrosoarchaeaum clade containing strains isolated from low-salinity and terrestrial environments, about 45% of total clones of the station 176 and 184 were related to marine Nitosopumilus clade. Interestingly, other typical archaeal amoA gene clones of thaumarchaeal I.1b clade frequently retrieved from terrestrial environments was identified at station 188. Microbial community of nitrogen cycle in marine sediment might be affected by input of sediments caused by runoff glacier melt waters.

• Journal of Yeungnam Medical Science
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• v.14 no.2
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• pp.337-349
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• 1997

This study was undertaken to examine the intensity of involvement of inducible nitric oxide synthase (iNOS) and cyclic GMP signal transduction pathway as one of the mechanisms of vaso-relaxative action of bacterial lipopolysaccharide (LPS) on the canine femoral artery strips. Canine femoral arteries were isolated and spiral strips of 10 mm long and 2 mm wide were made in the Tyrode solution of $0-4^{\circ}C$. The strips were prepared for isometric myography in Biancani's isolated muscle chamber containing 1 ml of Tyrode solution, which was maintained with pH 7.4 by aeration with 95% $O_2$/5% $CO_2$ at $37^{\circ}C$ and nitric oxide (NO) production was measured simulltaneously with isolated nitric oxide meter. LPS induced NO production, suppressed the phenylephrine (PE) induced contraction and enhanced the acetylcholine (ACh) induced relaxation. $N^G$-nitro-L-arginine methyl ester (L-NAME), an NOS inhibitor, methylene blue, a guanylyl cyclase inhibitor, potentiated PE induced contraction and suppressed ACh induced relaxation on the LPS treated strips. The inhibitory potency of methylene blue for LPS induced vascular hyporesponsiveness was stronger than that of L-NAME. These results suggest that in canine femoral artery, both iNOS and cyclic GMP signal trnasduction pathway are related with LPS induced vascular hyporeponsiveness, but in minor with iNOS and in major with cyclic GMP signal trnasduction pathway.

• Journal of Veterinary Clinics
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• v.21 no.1
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• pp.15-19
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• 2004

The emergence of bacterial resistance to antibiotics during therapy is a matter of great problem in clinical medicine. This may be because many veterinarians have used inappropriate antibiotics without bacteriological culture. Therefore, the purpose of this study is to determine isolation of anaerobic bacteria as pathogens from veterinary clinical specimens as well as susceptibility pattern for choosing antibiotics. Various anaerobic bacteria were isolated from clinical specimens of dogs, cats, rabbits at Veterinary Medical Teaching Hospital of Seoul National University from May 2001 to October 2002. The total number of isolated anaerobic bacteria was 13 isolates; Bacteroides spp. (3 isolates), Fusobacterium spp. (2 isolates), Peptostreptococcus spp. (2 isolates), Porphyromonas gingivalis (2 isolates), Prevotella spp. (3 isolates), and Propionibacterium acnes (1 isolate). For evaluating the antibiotic susceptibility patterns of the isolates disk diffusion method was used. All isolates were susceptable to all tested antibiotics except only one Fusobacterium varium was resistant to norfloxacin.

• Research in Plant Disease
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• v.20 no.3
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• pp.211-215
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• 2014

This research was performed to examine the protective activities of the mixtures of pine oil and copper hydroxide against bacterial spot and anthracnose on pepper plants. As for bacterial spot, the treatment of pine oil alone displayed high disease incidence (59.6%) and low protective effect (28.9%). In comparison, the treatments of mixtures and copper hydroxide alone showed protective activities of 66.8-76.1%. The mixture of pine oil and copper hydroxide (4:1) suppressed the most effectively bacterial spot on pepper. On the other hand, the mixture of pine oil and copper hydroxide (4:1) also showed the strongest protective effect against pepper anthracnose among the 4 treatments tested; its disease incidence and disease control value were 49.8% and 41.7%, respectively. The other treatments showed low protective activities with control values of 7.4-17.1%. These results suggested that the mixture of pine oil and copper hydroxide (4:1) can be used for the environmental-friendly disease control of bacterial spot and anthracnose on pepper.

• The Korean Journal of Mycology
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• v.38 no.1
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• pp.69-74
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• 2010

The 2 strains of Pleurotus ostreatus showing very severe and mild symptom of brown blotch were selected, and their F1 hybrid strains were made by mating of their single spore isolates. Hydrophobicity of fruiting body surface and brown blotch severity of the parental and their 11 F1 hybrid strains showing different level of severity of brown blotch were determined. Correlation coefficient (R) between disease severity and hydrophobicity were 0.68 and 0.70 on two independent experiments. Correlation coefficient between disease severity and disease incidence that was determined in the oyster mushroom farm were 0.46 and 0.52 on two independent experiments. When GFP-tagged Pseudomonas tolaasii was monitored with confocal microscope on cap surface of fruiting body, more cells of the pathogen were clustered on the severe strain than the mild strain, which indicates that the bacterial pathogen proliferates more on the severe strain. These results suggest that hydrophobicity of oyster mushroom fruiting body affects disease severity of the brown blotch disease; the longer the bacterial suspension stays on fruiting body surface more severe symptom of the blotch develops.

• Journal of Food Hygiene and Safety
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• v.34 no.1
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• pp.100-105
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• 2019

In this study, viable cells, coliforms and food poisoning bacteria were identified according to the pH levels of the coagulant and immersion liquid during each stage in the production of konjac, and storage stability was confirmed for 3 months. A considerable number of bacteria were found in the raw material, or powdered konjac (Amorphophallus konjac), as well as in the processing water. However, it has been shown that the plastic package were safe from microorganisms. Due to the high pH of the added coagulant [2.0% $Ca(OH)_2$], no contaminating bacteria were observed after konjac jelly formation. Coliforms were not detected any of the tested steps. During the molding process, the pH of konjac was adjusted to 9.5 ~ 12.5 at intervals of 0.5, and the number of bacteria was determined. As a result, no bacteria were detected in the alkaline range above pH 11.5. The pH of the immersion liquid was adjusted to 10.0 ~ 12.5, and after hardening, the konjac were stored at room temperature for 12 weeks. As a result, no bacteria, Escherichia coli or other food poisoning bacteria were detected at pH 11.5 or higher. Based on these results, it is expected that when the pH levels of the konjac and its immersion liquid are maintained at 11.5, it should be possible to keep the product for 3 months without additional sterilization process.

• Korean Journal of Microbiology
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• v.23 no.1
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• pp.43-48
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• 1985

Strict anaerobic procedures and anaerobic chamber were employed in order to improve the isolation of obligate anaerobes from oral pyogenic infections. Also different culture media were utilized to maximize bacterial recovery. Two blood media: nalidixic acid Tween blood agar (NATB) and plain blood agar (BA), two non-blood media: nalidixic acid Tween agar (NAT) and Gifu anaerobic medium (GAM) were used and compared for their isolation efficacy. Specimens from seven patients were collected with syringe. After collection, the needle was sealed with sterilixed silicone rubber and brought to labortory. The time spent from specimen collection to its processing in anaerobic chamber usually was 15 min. Identification of isolated bacterial strains was done with the API-20A system. Increase in isolation of anaerobic vacteria was achieved. Obligate anaerobic bacteria isolated were 3.3 strains per specimen. This figure falls within the range of 1.9-4.4 strains per specimen reported in other countries. With respect to the media utilized, blood media were superior to non-blood media. NATB medium was effective especially for the isolation of Gram-positive cocci. A total of 15 species of Gram-negative rods was isolated and 12 of them belonged to Bacteroides.

• The Korean Journal of Ecology
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• v.22 no.5
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• pp.305-309
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• 1999

The occurrence of tetQ and aacC2 genes encoding tetracycline and gentamicin resistance determinant, respectively, was assessed in total bacterial community DNA isolated from Dongchon stream of Sunchon area. To examine the resistance potential of bacteria that were not cultured, total DNA from 1 liter of stream water was extracted by freeze-thaw method. The PCR technique was employed to determine the abundance of the target genes. The highest frequency of tetQ gene was obtained from site 1, located near the animal farms area, whereas the incidence of aacC2 was highest in site 5, the downstream area. These results showed that the occurrence of antibiotic resistance gene may be used as a convenient marker of water quality related to source.

• 보존과학연구
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• s.37
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• pp.5-15
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• 2016

We isolated microorganisms from soil arounding the stump and surface of stump in Bubjusa temple in Boeun, Heungguksa temple in Yeosu and Leeyongwoo house in Boseong. As a result, a distribution percentage of bacteria was high and there was a region-specific difference in bacteria colony. There was greater microbial diversity and population in the Leeyongwoo house in Boseong.

• The Korean Journal of Food And Nutrition
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• v.11 no.1
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• pp.36-40
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• 1998

Areca catachu L. which was showed antimicrobial activity against intestinal pathogens through screening herbs related treatments of intestinal diseases, were extracted by methanol and fractionated by n-hexane, ethylether, ethylacetate, and water. Antimicrobial activities of the methanol extract and each fractionates were then investigated under the anaerobic broth system. All fractions of Areca catachu L. except of n-hexane showed antimicrobial activity against all tested pathogens. Especially, ethylacetate fraction of them had the most significant inhibition activity. There is no significant difference of antimicrobial activity among each fractionates. Fraction of Areca catachu L. ethylacetate fractionate, which were fractionated by Sephadex G-200 and Silica gel column chromatography revealed the strongest antimicrobial activity at 5 to 7 and 20 of fraction number, respectively.