• The Korean Journal of Community Living Science
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• v.21 no.3
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• pp.311-322
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• 2010

The purpose of this study was to examine food hygiene knowledge and health practice levels of elementary school students at foodservice in the Suwon area. Of the 500 upper graders from three elementary schools, 486 students (97.2%) participated in the study. The questionnaire was composed of general characteristics including experience of serving food at school, food hygiene knowledge (25 questions), and health practice (18 questions). The results were as follows: The education experiences of food hygiene were below 40% though most students (88.1%) participated in providing food at foodservice. The percentage of correct answers in food hygiene knowledge was over 70% in most questions, but relatively lower in food preservation temperature (44.7%) and food poisoning bacteria (43.2%). When we examined food hygiene behavior of elementary school students in 5scales, the level of personal hygiene management was 4.04, sanitary management in food product was 3.62, environmental hygiene was 3.92, and foodborn disease and food microorganism was 3.81. Each level in each subarea was significantly related in the frequency of hygiene education experiences. Finally, the food hygiene knowledge was positively correlated with its behavior level in elementary school foodservice. These results suggested that the knowledge of food hygiene may affect its behavior, and therefore, regular education of food hygiene at home and school would be needed to improve food safety in foodservice.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.4
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• pp.2099-2103
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• 2016

Background: The gold standard diagnosis of H. pylori related gastritis is evidence of bacteria on histopathological examination of gastric mucosa. Our aim was to study the correlation between gastric mucosal morphology and histopathological severity of H. pylori related gastritis. Materials and Methods: Division was made on morphological features into:Type 1, showing regular arrangement of red dots; Type 2, showing cleft-like appearance; Type 3, with a mosaic appearance; and Type 4, having a mosaic appearance with focal or diffuse hyperemia. Results: Types 1 and 2 gastric mucosal morphologies were statistically significant in predicting an H. pylori negative status (137/145, p<0.01), while Types 3 and 4 were significant a positive status (139/155, p<0.01). The sensitivity, specificity, positive and negative predictive values of Type 3 and 4 morphologies for predicting H. pylori positive were 94.6%, 89.5%, 89.7% and 94.5%, respectively, with a good correlation with inflammation grading (p<0.01). Conclusions: Our study suggests that gastric mucosal morphology can be reliably identified using conventional white light source gastroscopy with good correlation between findings and inflammation grading.

• Journal of Microbiology and Biotechnology
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• v.22 no.4
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• pp.462-469
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• 2012

A metagenomic fosmid library was constructed from genomic DNA isolated from the microbial community residing in hindguts of a wood-feeding higher termite (Microcerotermes sp.) collected in Thailand. The library was screened for clones expressing lignocellulolytic activities. Fourteen independent active clones (2 cellulases and 12 xylanases) were obtained by functional screening at pH 10.0. Analysis of shotgun-cloning and pyrosequencing data revealed six ORFs, which shared less than 59% identity and 73% similarity of their amino acid sequences with known cellulases and xylanases. Conserved domain analysis of these ORFs revealed a cellulase belonging to the glycoside hydrolase family 5, whereas the other five xylanases showed significant identity to diverse families including families 8, 10, and 11. Interestingly, one fosmid clone was isolated carrying three contiguous xylanase genes that may comprise a xylanosome operon. The enzymes with the highest activities at alkaline pH from the initial activity screening were characterized biochemically. These enzymes showed a broad range of enzyme activities from pH 5.0 to 10.0, with pH optimal of 8.0 retaining more than 70% of their respective activities at pH 9.0. The optimal temperatures of these enzymes ranged from $50^{\circ}C$ to $55^{\circ}C$. This study provides evidence for the diversity and function of lignocellulose-degrading enzymes in the termite gut microbial community, which could be of potential use for industrial processes such as pulp biobleaching and denim biostoning.

• Journal of Microbiology and Biotechnology
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• v.20 no.3
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• pp.447-459
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• 2010

Bacterial diversity of two distinct wastewater treatment systems, conventional activated sludge (CAS) and membrane bioreactor (MBR), of petroleum refineries were investigated through 16S rRNA gene libraries. Sequencing and phylogenetic analysis showed that the bacterial community composition of sludge samples was distinct between the two wastewater treatment systems. MBR clones belonged predominantly to Class Betaproteobacteria, represented mainly by genera Thiobacillus and Thauera, whereas CAS clones were mostly related to Class Alphaproteobacteria, represented by uncultured bacteria related to Order Parvularculales. Richness estimators ACE and Chao revealed that the diversity observed in both libraries at the species level is an underestimate of the total bacterial diversity present in the environment and further sampling would yield an increased observed diversity. Shannon and Simpson diversity indices were different between the libraries and revealed greater bacterial diversity for the MBR library, considering an evolutionary distance of 0.03. LIBSHUFF analyses revealed that MBR and CAS communities were significantly different at the 95% confidence level ($P{\leq}0.05$) for distances $0{\leq}D{\leq}0.20$. This work described, qualitatively and quantitatively, the structure of bacterial communities in industrial-scale MBR and CAS processes of the wastewater treatment system from petroleum refineries and demonstrated clearly differentiated communities responsible for the stable performance of wastewater treatment plants.

• Korean Journal of Ecology and Environment
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• v.38 no.2 s.112
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• pp.261-270
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• 2005

Biological control agents (BCA; algicidal bacterium Xantobacter autotrophycus) plus casitone media, strongly changed physicochemical variables, standing crops of phytoplankton and microcystin-LR phytoplankton in 100-L mesocosm constructed in a small hexagonal pond (3.5 m ${\times}$ 5 m). No M. aeruginosa showed by 8 days, and 60% of total standing crops of phytoplanktons were decreased by the BCA treatment. BCA treatment also induced a strong decline of cellular extracted microcystin-LR (MCLR) and a remarkable increase of dissolved MCLR with the decrement in standing crops of cyanobacteria. In addition, BCA strongly increased all nutrients, but new outbreak of phytoplanktons hardly showed in the experimental mesocosm. The field application of BCA to controling the cyanobacterial bloom in large lakes and reservoirs is not relevant due to high concentration of nutrients and toxins. Thus, a further study is needed to diminish the adverse effects after BCA treatment for water quality preservation.

• Journal of Microbiology and Biotechnology
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• v.20 no.5
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• pp.925-934
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• 2010

Three typical biological solid wastes, namely, animal manure, garbage, and sewage sludge, were compared with regard to the composting process and the changes in microbial community structure. The effects of different bulking agents such as rice straw, vermiculite, sawdust, and waste paper were compared in manure compost. The differences in the microbial community were characterized by the quinone profile method. The highest mass reduction was found in garbage composting (56.8%), compared with manure and sludge (25% and 20.2%, respectively). A quinone content of $305.2\;{\mu}mol/kg$ was observed in the late stage of garbage composting, although the diversity index of the quinone profile was 9.7, lower than that in manure composting. The predominant quinone species was found to be MK-7, which corresponds to Gram-positive bacteria with a low G+C content, such as Bacillus. The predominance of MK-7 was especially found in the garbage and sludge composting process, and the increase in quinones with partially saturated long side-chains was shown in the late composting process of manure, which corresponded to the proliferation of Actinobacteria. The effects of different bulking agents on the composting process was much smaller than the effects of different raw materials. High organic matter content in the raw materials resulted in a higher microbial biomass and activity, which was connected to the high mass reduction rate.

• Research in Community and Public Health Nursing
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• v.15 no.4
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• pp.618-627
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• 2004

Purpose: To investigate the dental health status of kindergarten children according to their oral health behavior. Method: The subjects were 172 kindergarten children aged 5. A structured questionnaire was used for dental health behavior and oral health status were examined by dentist and bacteria in salivary. Result: 1. Mean score of oral health behavior of children was 4.69 points (SD1.65) with the highest score being 13. No significant differences were observed according to sex, except using tooth paste. A total 71.5% of subjects brushed their tooth twice a day, 9.9% of them once a day, 18.6% of them three times a day, 19.2% of children brushed their teeth after breakfast and lunch, 89.5% of then after dinner, 5.8% of them before going to bed, 18.6% of children brushed correctly, 79.7% of them used tooth paste with fluorine, 3.5% of them regularly examined oral cavity, 84.4% of them took cariogenic food without any restrain, 67.1% of them were observed with oral cavity by their mother. 2. Streptococcus mutans and lactobacilli in the saliva was $3.66({\times}106CFU/m{\ell})\;and\;1.05({\times}103CFU/m{\ell})$, respectively. No significant differences were observed according to sex, while lactobacilli were significantly lower in those children who had regular dental examinations. 3. The index of plaque was 1.56 and the boys were significantly higher than the girls. The mean dft was 4.99. No significant differences were observed according to sex, while the children whose oral cavity was observed regular were significantly lower than those who were not observed. Conclusion: As a whole the practice of oral health behavior of the kindergarten children was poor, and regular dental examinations and oral cavity observations affect their dental health status. These results suggest that intensive dental health education was needed not only for the pre-school children but also their parents and teachers.

• Journal of Ecology and Environment
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• v.41 no.9
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• pp.235-245
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• 2017

Background: Loading of excess nutrient via bioremediation of polluted sediment to overlying water could trigger anoxia and eutrophication in coastal area. The aim of this research was to understand the changes of overlying water features such as dissolved oxygen (DO); pH; oxidation reduction potential (ORP); $chlorophyll-{\alpha}$ ($Chl-{\alpha}$); and nitrogen nutrients ammonia ($N-NH_4{^+}$), nitrate ($N-NO_3{^-}$), and nitrite ($N-NO_2^-$) when the sediment was not treated (control) and treated by calcium peroxide for 5 weeks. Methods: The water samples were analyzed for measuring physical and chemical properties along with the sediment analyzed by polymerase chain reaction (PCR) including denaturing gradient gel electrophoresis (DGGE) for identifying the phylogenetic affiliation of microbial communities. Results: Results showed that due to the addition of calcium peroxide in sediment, the overlying water exposed the rise of dissolve oxygen, pH, and ORP than control. Among the nitrogen nutrients, ammonia inhibition was higher in calcium peroxide treatment than control but in case of nitrate inhibition, it was reversed than control. $Chlorophyll-{\alpha}$ was declined in treatment column water by 30% where it was 20% in control column water. Actibacter and Salegentibacter group were detectable in the calcium-peroxide-treated sediment; in contrary, no detectable community ware found in control sediment. Both phylogenetic groups are closely related to marine microflora. Conclusions: This study emphasizes the importance of calcium peroxide as an oxygen release material. Interaction with peroxide proved to be enhancing the formation of microbial community that are beneficial for biodegradation and spontaneity of nutrient attenuation into overlying water.

• Korean Journal of Microbiology
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• v.25 no.4
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• pp.318-327
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• 1987

Taxonomic composition and diversity were wxamined by statistical analysis for bacterial communities in surface waters of the Sudong Stream, a tributary of North Han River. For total 282 isolates, Flavobacterium, Aeromonas and Enterobacteriaceae was identified by the deterministic schemes as a major group above 50% of total isolates in all sampling sites. Morphological, biochemical and physiological characteristics were numerically analyzed for bacterial isolates from each site and clustered into 15-28 groups. Not all statistically clustered groups were identical to the groups derived from deterministic identification. Especially, consistent relationship was not found in dendrograms for the groups with each a single strain which gas peculiar sugar-degrading activity. At a level of 80% similarity, bacterial diversity (H) was ranged as 2.37-3.14, and it was suggested that the research area was oligotrophic-mesotrophic status. Regional distribution of bacterial community was most heterogeneous at the site where large input of allochthonous materials or bacteria were occurred. And that was the significant factor for the compositions of bacterial communities in the Sudong stream.

• Journal of the Korean Society of Marine Environment & Safety
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• v.12 no.2 s.25
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• pp.89-98
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• 2006

The microbial response after treatment of antibiotics was studied for investigating the resistance pattern under simulated aquaculture environment. A marine microcosm was developed for marine fish farm environment using artificial seawater and sediment. Oxolinic acid, which has been commonly used in aquaculture, was employed for the experiment. Resistance patterns and the changes of microbial community were monitored before. during and after use of oxolinic acid. Vibrionaceae was the dominant bacterial species throughout the experiment, consisting 65-75% of total bacterial number in fish farm environment. However, some gram-positive bacteria, Micrococcos sp. and Bacillus sp. strains in marine farm environment were increased in proportion to their number during the treatment. ETS activity of the bacterial communities in aquaculture environment was reduced to 42-67% during the treatment of oxolinic acid. But recovering trends of bacterial number were also detected immediately after cease of oxolinic acid treatment. Frequent treatment of oxolinic acid under the simulated fish farm environment showed bacterial resistance to increase sharply.