• Korean Journal of Fisheries and Aquatic Sciences
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• v.7 no.2
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• pp.41-51
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• 1974

A study of the sanitary quality of Pacific oysters (Crassostrea gigas) and growing waters associated with raft culture in Burley Lagoon, Washington was conducted. The study was sponsored by the Agency for International Development of the U.S. Department of State. The results obtained in this study are as follows: The average values of temperature, salinity and turbidity in the water showed that the values of bottom sample were slightly higher than top samples. The difference was about $0.3^{\circ}C$ for temperature, $0.5\%_{\circ}$ for salinity and 0.1 JTU for turbidity. The changes of temperature and salinity by tide generally followed the tide cycle pattern. Sanitary indicator microorganism concentrations in top water were generally higher than those in bottom water. In general, the levels of mean coliform and fecal coliform MPN's varied inversely with tide level indicating that the sources of these groups of microorganisms are the fresh water streams flowing into the estuary. The $35^{\circ}C$ plate counts were more stable at different tide levels. Mean values of coliform and fecal coliform MPN's in oysters demonstrated that levels in top oysters were generally higher than those in bottom oysters. However, mean values of $35^{\circ}C$ Plate count in oysters did not show this pattern. The mean levels of both coliform and fecal coliform MPN's in oysters also correlated inversely with tidal level. The accumulation ratios of oysters obtained during the study period ranged from 8.6 to 19.7 for mean coliform MPN and 16.9 to 44.3 for fecal coliform MPN. According to the results obtained from present study, one suggestion could be of considerable importance for the sanitary operation in hanging culture of pacific oysters. The results indicate that harvest of the oysters at high tide would result in lower levels of indicator organisms in the shellfish.

• Food Science of Animal Resources
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• v.28 no.1
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• pp.76-81
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• 2008

The objective of this study is to evaluate the microbial safety of raw pork used to produce Korean pork jerky. The raw pork samples harbored large populations of microorganisms. In particular, mesophilic bacteria were found to be most numerous $(3.9{\times}10^2-3.9{\times}10^5cfu/g)$ in the samples. Spore-forming bacteria and coliforms were not detected below detection limit. Yeast and molds were detected at $3.8{\times}10^1-5.1{\times}10^2cfu/g$ in the raw pork. Ten samples of raw pork were analyzed for the presence of pathogenic bacteria. Bacillus cereus was isolated from samples B and J and Staphylococcus aureus was isolated from sample B. The B. cereus isolates from raw pork samples were identified with 99.8% agreement and S. aureus isolate was identified with 97.8% agreement according to the API CHB 50 kit.

• Korean Journal of Food Science and Technology
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• v.34 no.5
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• pp.927-930
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• 2002

Spinach minimally processed using cook-chill and sous vide techniques was vacuum-packed in low gas permeable plastic film, pasteurized at $70^{\circ}C$ for 2 min, cooled rapidly at $3^{\circ}C$, and stored at 3 and $10^{\circ}C$. Contents of mesophilic bacteria, psychrophilic bacteria, anaerobic bacteria, spore-forming bacteria, total coliforms, yeast and molds, fecal Streptococcus, and Enterobacteriacea were measared to identify the degree of food contamination. Number of mesophilic bacteria, detected at $2.2{\times}10^8\;cfu/g$ in raw spinish, decreased to about $6.0{\times}10^3\;cfu/g$ after cook-chill process. During the storage at 3 or $10^{\circ}C$, levels of mesophilic, psychrophilic and anaerobic bacteria increased, whereas total coliforms, yeast and molds, fecal Streptococcus, and Enterobacteriacea were not detected. Twelve strains of Aeromonas hydphila, Escherichia coli O157:H7, Plesiomonas shigelloides, Pseudomonas aeruginosa, Salmonella spp., Shigella spp., Yersinia enterocolitica, Bacillus cereus, Campylococcus spp., Clostridium perfringens, Listeria monocytogenes, and Staphylococcus aureus were examined for detecting the presence of pathogenic bacteria in spinach. B. cereus and C. perfringens were isolated from raw, washed, and cook-chilled spinach, whereas A. hydrophila was isolated only from washed spinach. S. aureus was isolated from raw and washed spinach, but not from cook-chilled spinach. Other pathogenic organisms were not detected in raw, washed, and cook-chilled spinach.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.10
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• pp.979-985
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• 2010

This study was performed to detect enterococci strain as an indicator of faecal contamination, to identify of 16S rDNA sequence and vancomycin resistance by MIC (Minimum Inhibitory Concentration) test from drinking spring-water samples in Seoul. The detection frequency of enterococci was 42 (19.8%) among 212 samples, and its concentration was ranged from 0 to 110 CFU/100 mL. These results were confirmed the possibility as an indicator microorganisms that similar to the frequency of E. coli detection (t test p-value 0.268, significant level 0.05). Isolated 56 enterococci samples were identified by 16S rDNA sequence data and their NCBI BLAST searching. They were identified to Enterococcus faecalis of 24 samples, E. faecium (10), E. casseliflavus (10), E. gallinarum (3), E. hirae (2), E. durans (2), E. sanguinicola (1). E. faecalis was dominant species that clinical case report of a domestic was similar. Vancomycin resistant enterococci (VRE) of 53 samples showed that vanB and vanC1/C2 type with 2 and 12 case, respectively. These results indicated that the drinking spring-water quarantined to fecal pollution for block out outbreak of gastrointestinal symptom with using such as disinfection process.

• Journal of Environmental Health Sciences
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• v.42 no.4
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• pp.280-292
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• 2016

Objectives: The objective of this study was to build COD regression models for the Han River and evaluate water quality. Methods: Water quality data sets for the dry season (as of January) during a four-year period (2012-2015) were collected from the database of the Han River automatic water quality monitoring stations. Statistical techniques, including combined genetic algorithm-multiple linear regression (GA-MLR) were used to build five-descriptor COD models. Multivariate statistical techniques such as principal component analysis (PCA) and cluster analysis (CA) are useful tools for extracting meaningful information. Results: The $r^2$ of the best COD models provided significant high values (> 0.8) between 2012 and 2015. Total organic carbon (TOC) was a surrogate indicator for COD (as COD/TOC) with high reliability ($r^2=0.63$ in 2012, $r^2=0.75$ for 2013, $r^2=0.79$ for 2014 and $r^2=0.85$ for 2015). The ratios of COD/TOC were calculated as 2.08 in 2012, 1.79 in 2013, 1.52 and 1.45 in 2015, indicating that biodegradability in the water body of the Han River was being sustained, thereby further improving water quality. The BOD/COD ratio supported these findings. The cluster analysis revealed higher annual levels of microorganisms and phosphorous at stations along the Hangang-Seoul and Hantangang areas. Nevertheless, the overall water quality over the last four years showed an observable trend toward continuous improvement. These findings also suggest that non-point pollution control strategies should consider the influence of upstreams and downstreams to protect water quality in the Han River. Conclusion: This data analysis procedure provided an efficient and comprehensive tool to interpret complex water quality data matrices. Results from a trend analysis provided much important information about sources and parameters for Han River water quality management.

• Applied Chemistry for Engineering
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• v.19 no.1
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• pp.122-128
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• 2008

We evaluated the relationship between the multiplication of heterotrophic microorganisms and physicochemical factors in the final discharged sewage water from J municipal waste water treatment plants. Dissolved organic carbon (DOC) was the most crucial factor influencing multiplication of heterotrophic plate counts (HPC) among the water quality variables selected. Degrading bacteria, such as proteolytic bacteria, lipholytic bacteria, starch degrading bacteria, cellulolytic bacteria, and pectinolytic bacteria, were monitored to understand the condition of nutrients in finished sewage effluent. The percentages of lipid and protein combined occupied 81% in finished sewage water. The multiplication of HPC showed the highest value in August. The formation of trihalomethane (THM) was low in the finished discharge water during chlorine disinfection, which was $71{\mu}/L$ (which was less than $100{\mu}/L$- the standard of drinking water quality) with 10 mg/L of chlorine during 15 min.

• Journal of Environmental Science International
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• v.27 no.8
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• pp.621-629
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• 2018

Many chemically active species such as ${\cdot}H$, ${\cdot}OH$, $O_3$, $H_2O_2$, hydrated $e^-$, as well as ultraviolet rays, are produced by Dielectric Barrier Discharge (DBD) plasma in water and are widely use to remove non-biodegradable materials and deactivate microorganisms. As the plasma gas containing chemically active species that is generated from the plasma reaction has a short lifetime and low solubility in water, increasing the dissolution rate of this gas is an important challenge. To this end, the plasma gas and water within reactor were mixed using the air-automizing nozzle, and then, water-gas mixture was injected into water. The dissolving effect of plasma gas was indirectly confirmed by measuring the RNO (N-Dimethyl-4-nitrosoaniline, indicator of the formation of OH radical) solution. The plasma system consisted of an oxygen generator, a high-voltage power supply, a plasma generator and a liquid-gas mixing reactor. Experiments were conducted to examine the effects of location of air-automizing nozzle, flow rate of plasma gas, water circulation rate, and high-voltage on RNO degradation. The experimental results showed that the RNO removal efficiency of the air-automizing nozzle is 29.8% higher than the conventional diffuser. The nozzle position from water surface was not considered to be a major factor in the design and operation of the plasma reactor. The plasma gas flow rate and water circulation rate with the highest RNO removal rate were 3.5 L/min and 1.5 L/min, respectively. The ratio of the plasma gas flow rate to the water circulation rate for obtaining an RNO removal rate of over 95% was 1.67 ~ 4.00.

• Ocean and Polar Research
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• v.35 no.4
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• pp.415-425
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• 2013

In order to understand phytoplankton and bacterial distribution in tropical coral reef ecosystems in relation to the mangrove community, their biomass and activities were measured in the sea waters of the Chuuk and the Kosrae lagoons located in Micronesia. Chlorophyll a and bacterial abundance showed maximal values in the seawater near the mangrove forests, and then steeply decreased as the distance increased from the mangrove forests, indicating that environmental conditions for these microorganisms changed greatly in lagoon waters. Together with chlorophyll a, abundance of Synechococcus and phototrophic picoeukaryotes and a variety of indicator pigments for dinoflagellates, diatoms, green algae and cryptophytes also showed similar spatial distribution patterns, suggesting that phytoplankton assemblages respond to the environmental gradient by changing community compositions. In addition, primary production and bacterial production were also highest in the bay surrounded by mangrove forest and lowest outside of the lagoon. These results suggest that mangrove waters play an important role in energy production and nutrient cycling in tropical coasts, undoubtedly receiving large inputs of organic matter from shore vegetation such as mangroves. However, the steep decrease of biomass and production of phytoplankton and heterotrophic bacteria within a short distance from the bay to the level of oligotrophic waters indicates that the effect of mangrove waters does not extend far away.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.40 no.5
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• pp.288-292
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• 2007

Seafood, if eaten raw, carries the risk of food poisoning. Seafood poisoning is often caused by pathogenic microorganisms originating from fecal contamination, such as Salmonella sp. and norovirus. Fecal coliforms are an important indicator of fecal contamination. Therefore, data on fecal coliforms are very important for evaluating the safety of fisheries in coastal areas. In this study, 2,226 sea water samples were collected from the southeast coast of Korea, and total and fecal coliforms were compared and analyzed. Total coliforms were detected in 76.5% of the samples and 71.4% of the total coliforms were fecal coliforms. At sea water temperatures above $20.0^{\circ}C$, total coliforms were found in 78.8% of the samples and fecal coliforms constituted 72.0% of the total coliforms. In sea water below $19.9^{\circ}C$, the respective values were 74.6% and 70.9%. These results suggest that temperature does not have a significant effect on the detection of fecal coliforms. When the salinity exceeded 30.0%o, total coliforms were found in 72.1% of the samples and fecal coliforms constituted 66.0% of these. At salinities below 29.9%o, the respective values for total and fecal coliforms were 90.4% and 85.2%. These results strongly suggest that the detection of fecal coliforms is proportional to the amount of precipitation.

• Microbiology and Biotechnology Letters
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• v.23 no.3
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• pp.365-371
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• 1995

Filamentous bacteria and other large microorganisms, which are useful indicators of bulking and poeration, were identified by microscopic observation. Activated sludge samples were taken from the aeration basin of 5 municipal wasterwater plants and 6 industrial ones. Among the filamentous bacteria founds, Microthrix parvicella was most frequently present, followed by type 0041, type 1701 and Nocardia. This frequency of occurrence was similar to those reorted in USA and the Neterland. The morphology of filamentous bacteria observed were generally identical with those previously reported. except type 1701 which had slender filament diameter. Among protozoa, Vorticella was most frequently present, followed by Aspidisca, Opercularia and Difflugia. Philodina was the only metazoa observed. Both filamentous bacteria and protozoa would be useful indicator organisms. The potential for these organisms as indicators were discussed.