• Journal of Environmental Science International
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• v.8 no.1
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• pp.101-106
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• 1999

The relationship between primary productivity and changes in water quality was investigated at Mulgum station, a site downstream of the Nakdong River, Korea. Phytoplankton production was characterized by blooms of Microcystis aeruginosa during the summer and Stephanodiscus hantzschii during the winter. Primary production and secondary production by bacterioplankton ranged from 1.5~53.5 mg-C/ι day and 0.1~0.3 mg-C/ι day, respectively. Distribution of total organic carbon appeared to be highly correlated with phytoplankton biomass, especially during blooms of M. aeruginosa, when particulate organic carbon was 81% of total organic carbon and the main source of organic materials supplied into the water. The correlation coefficient between chlorophyll-a and BOD was 0.86. Thus it was concluded that autochthonous phytoplankton mostly affected the BOD level. Total bacterial numbers were also highly correlated with chlorophyll-a ($r^2$= 0.84) and the bacterial community appears to be regulated by phytoplankton biomass in this area.

• Korean Journal of Veterinary Service
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• v.26 no.1
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• pp.27-31
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• 2003

In order to monitoring the chicken meat hygiene, 165 chicken samples were tested for contamination agents such as the total bacterial counts, coliform bacterial counts and falling bacterial counts. The prevalence of level on number of standard plate count(SPC), total bacterial counts in less than 10$^3$cfu/$\textrm{cm}^2$, 10$^3$∼10$^4$cfu/$\textrm{cm}^2$ and 10$^4$∼10$\^$5/cfu/$\textrm{cm}^2$ were 30 samples (18.2%), 98 samples(59.4%) and 37 samples(22.4%), respectively. The coliform bacterial counts in less than 10$^2$cfu/$\textrm{cm}^2$, 10$^2$∼10$^3$cfu/$\textrm{cm}^2$ and 10$^3$∼10$^4$cfu/$\textrm{cm}^2$ were 7 samples(4.2%), 66 samples (40.0%), 92 samples(55.8%), respectively. The falling bacterial counts in plants were higher 9.1, in summer 8.4, in fall 7.2 in spring and 6.7 in winter decreased.

• Korean Journal of Veterinary Service
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• v.26 no.3
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• pp.221-225
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• 2003

In order to monitoring the chicken meat hygiene, 165 chicken samples were tested for contamination agents such as the total bacterial counts, coliform bacterial counts and falling bacterial counts. The prevalence of level on number of standard plate count, total bacterial counts in less than $10^3\;cfu/cm^2$, $10^3{\sim}10^4\;cfu/cm^2$ and $10^3-10^5\;cfu/cm^2$ was 30 samples(18.2%), 98 samples(59.4%) and 37 samples(22.4%), respectively. The coliform bacterial counts in less than $10^2\;cfu/cm^2$, $10^2{\sima}10^$\;cfu/cm^2$ and $10^3{\sim}10^4\;cfu/cm^2$ was 7 samples(42.2%), 66 samples(40.0%), 92 samples(58.8%), respectively. The falling bacterial counts in plants was higher 9.1 in summer, 8.4 in fall, 7.2 in spring and 6.7 in winter, in order.

• Journal of Environmental Health Sciences
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• v.42 no.2
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• pp.126-132
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• 2016

Objectives: This study aims to provide basic data regarding the bacterial total plate count in the atmospheric environment for related studies. Methods: Total plate count and the identification of culturable bacteria in the atmospheric environment in Incheon took place in 2015 using periodic survey. Correlationship analysis was performed between the number of culturable bacteria and environmental elements. In addition, an estimation of novel bacterial species was undertaken using the similarities and phylogenetic tree based on the 16S rRNA gene. Results: The total plate count of culturable bacteria was on average $176CFU/m^3$, and did not exceed $610CFU/m^3$ in the atmospheric environment. Periodic monthly measuring of total plate count was highest in June at $293CFU/m^3$, while the lowest was in July at $125CFU/m^3$. Furthermore, as a result of the identification of culturable bacteria, the genera Arthrobacter and Kocuria were dominant, while novel bacterial taxa that belong to the genera Chryseobacterium and Herbiconiux were separated. Conclusion: The total number of culturable bacteria from the atmospheric environment in Korea is on average $176CFU/m^3$. In addition, the genera Arthrobacter and Kocuria dominate. The presence of novel bacterial taxa are expected in the atmospheric environment, such as belonging to the genera Chryseobacterium and Herbiconiux.

• Journal of Periodontal and Implant Science
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• v.38 no.4
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• pp.639-644
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• 2008

Purpose: The aim of this study was to compare the number of live and dead bacteria attached to, or within, the stratified squamous epithelium lining the tissue side of the gingival sulcus. Materials and Methods: A total of 50 patients was examined and classified into healthy or diseased sites according to inflammatory status of the gingival tissue. The surface of stratified squamous epithelium was removed by gentle scraping of the gingival sulcus with curettes. The cells were processed in the laboratory by density-gradient centrifugation to separate the epithelial cells from the loose bacteria and debris. The LIVE/$DEAD^{(R)}$ $BacLight^{TM}$ Bacterial Viability Kit was applied and the specimens were observed by an epifluorescent microscope and the number of bacteria was counted. Results: Live and dead bacteria were stained to green and red, irrespectively. Generally, the number of total bacteria in the diseased sites was significantly higher than in the healthy sites. The mean number of detected bacteria in the diseased sites was $58.6{\pm}36.0$ (red bacteria $10.4{\pm}9.2$ / green bacteria $48.2{\pm}30.5$), while it was $1.5{\pm}1.7$ in the healthy sites (red bacteria $0.1{\pm}0.3$ / green bacteria $1.4{\pm}1.5$). The percentage of red bacteria was $17.5{\pm}11.2%$ in the diseased sites and $2.0{\pm}5.8%$ in the healthy sites. Conclusion: The total number of bacteria in the diseased sites was significantly higher than that of the healthy sites. The ratio and the number of red bacteria were also significantly higher in the diseased sites.

• Korean Journal of Microbiology
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• v.32 no.3
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• pp.238-244
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• 1994

To investigate the bacterial potentials for utilizing dissolved organic matter in highly eutrophic estuary, the annual fluctuations of microbiological and physicochemical environmental parameters were analyzed in Naktong River Estuary. Total bacterial number ranged from 0.33 to $2.09{\times}10^7$ cells/ml, and correlated with the heterotrophic bacterial numbers in more eutrophic sites, especially. Bacterial biovolume and biomass varied between 0.064 and 0.156 2.09${\mu}m^3$/cell, 0.163 and 1.036 ${\mu}g$-C/ml, respectively. Bacterial secondary productivity ranged from 0.24 to 60.86 ${\mu}g$-C/l/h, and showed high correlations with the environmental parameters of pollution indicator. The seasonal variation pattern of bacterial productivity in freshwater sites was high in winter and low in summer, which was interpreted as the results of pollution loads varied with the amount of rainfall. In seawater site, the pattern was different from those of freshwater sites; high in summer and low in winter. In this site, the values of bacterial productivity showed positive correaltions with chlorophyll a, heterotrophic bacterial number, and temperature (r>0.5, p<0.05). These results suggested that the main source of organic matter which influences the bacterial productivity may be allochthonous materials in the upper freshwater zone of Naktong River Barrage, and autochthonous algal excretory products in the lower seawater zone of Naktong River Barrage.

• Journal of Microbiology
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• v.42 no.4
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• pp.278-284
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• 2004

Changes in the soil bacterial community of a coniferous forest were analyzed to assess microbial responses to wildfire. Soil samples were collected from three different depths in lightly and severely burned areas, as well as a nearby unburned control area. Direct bacterial counts ranged from $3.3­22.6\times10^8\;cells/(g{\cdot}soil).$ In surface soil, direct bacterial counts of unburned soil exhibited a great degree of fluctuation. Those in lightly burned soil changed less, but no significant variation was observed in the severely burned soil. The fluctuations of direct bacterial count were less in the middle and deep soil lay­ers. The structure of the bacterial community was analyzed via the fluorescent in situ hybridization method. The number of bacteria detected with the eubacteria-targeted probe out of the direct bacterial count varied from $30.3\;to\;84.7\%,$ and these ratios were generally higher in the burned soils than in the unburned control soils. In the surface unburned soil, the ratios of $\alpha,\;\beta\;and\;gamma-proteobacteria,$ Cytoph­aga-Flavobacterium group, and other eubacteria groups to total eubacteria were 9.9, 10.6, 15.5, 9.0, and $55.0\%,$ respectively, and these ratios were relatively stable. The ratios of $\alpha,\;\beta\;and\;gamma-proteobacteria,$ and Cytophaga-Flavobacterium group to total eubacteria increased immediately after the wildfire, and the other eubacterial proportions decreased in the surface and middle layer soils. By way of contrast, the composition of the 5 groups of eubacteria in the subsurface soil exhibited no significant fluctuations dur­ing the entire period. The total bacterial population and bacterial community structure disturbed by wildfire soon began to recover, and original levels seemed to be restored 3 months after the wildfire.

• Journal of Environmental Health Sciences
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• v.12 no.2
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• pp.39-48
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• 1986

This study was carried out to investigate the bacterial contamination of Ice Tea sold on the l street in Seoul area. For this, study 81 samples were collected on the street from July to September, 1985 and were examined on the following items. 1. Degree of bacterial contamination. 2. The relation of the occurrence of fecal coliform and salmonella. 3. The change of bacterial contamination in Ice Tea against temperature. As the results of this study, the following conclusion were obtained. 1. The mean count of total viable bacteria by standard plate count was $6.5{\times}10^3$/ml, the mean count of total coliform and fecal coliform by MPN method were $3.4{\times}10^2$/100ml, 5.5/100ml and those of fecal streptococci was $3.2{\times}10^2$/100ml. 2. The mean count of Staphylococcus aureus was 10.5/ml, the isolated rate of salmonella was 7.41%. 3. In relation to the occurrence of fecal colfform and salmonella, salmonella isolated that for values above $10^2$ fecal coliform 100ml. 4. In the change of bacterial contamination in Ice Tea against temperature, the number of total coliform and fecal coliform increased at $25{\circ}$C, decreased at $4{\circ}$C, but fecal streptococci increased at $25{\circ}$C and $4{\circ}$C.

• Journal of Korean Society of Water and Wastewater
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• v.22 no.2
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• pp.205-212
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• 2008

This study aimed to investigate the biofilm formation, bacterial regrowth, and bacterial community structure in the granular-activated carbon (GAC) filter adsorbers (FAs) used in water treatment plants. In 2005 and 2006, raw water, settled water, GAC FA by depth, and filtered water were collected twice a year from water treatment plants (WTPs) B and S. The number of heterotrophic bacteria, including mesophilic and psychrophilic bacteria, in such collected waters was investigated along with the total number of coliforms therein. Heterotrophic bacteria were detected in most samples, mainly at the surface layers of the GAC FAs, and fewer such bacteria were found in the lower and bottom layers. An increase in the bacterial number, however, was observed in the samples from various depths of the GAC FAs in WTPs B and S compared with the surface layers. An increase in the bacterial number was also detected in the filtered water. This may indicate that there is a regrowth of the bacteria in the GAC FA. Considering, however, that heterotrophic bacteria were not found in the filtered water, it can be deduced that most bacteria are removed in the chlorination process. Coliforms were detected at the surface layer of the GAC FAs, but their regrowth was not observed. MicroLog systems were used to identify the bacteria community distribution. Eight genera and 14 species, including Pseudomonas spp., were detected in WTP B, and 8 genera and 9 species, including Aeromonas spp., in WTP S. Further studies are required to elucidate their role in the biofilms in water treatment processes.

• The Korean Journal of Ecology
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• v.17 no.2
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• pp.171-183
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• 1994

Soil condition, total number of bacteria, soil amylase activity and microbial biomass $(CO_2-C)$ were measured at soil of different forest types. And the difference of the allelopathic effect was determined between fresh leaf extract of Quercus acutissima and Pinus rigida to the bacteria isolated from soil of different forest types. 1. Total number of bacteria in Carpinus laxiflora forest soil was 4~7 times larger than that in pinus desiflora forest soil. 2. Soil amylase activity was positively correlated with total number of soil bacteria and soil organic matter content. The amylase activity at F layer was 4~5 times larger than that at H layer, and that at H layer was 2~4 times larger than that at A layer. 3. Seasonal changes of microbial biomass showed a peak in summer, and vertical distribution of microbial biomass decreased with increasing soil depth. The microbial biomass in Pinus densiflora forest soil was larger than that in Quercus serrata forest soil. 4. Fresh leaf extract of Pinus rigida and Quercus acutissima showed an acceleration or inhibition effect on the growth of soil bacteria, and that of !. acutissima inhibited larger number of soil bacterial strains than that of P. rigida. 4.2% and 25% of soil bacterial strains isolated from soil of P. rigida and Q. acutissima forests were inhibited by fresh leaf extract of P. rigida and Q. acutissima, respectively.