• Food Science and Biotechnology
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• 제17권6호
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• pp.1337-1340
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• 2008

The objective of this study was to evaluate the microbial safety of raw beef used to produce Korean beef jerky, The raw beef samples harbored large populations of microorganisms. In particular, psychrophilic bacteria were found to be most numerous ($9.2{\times}10^3-1.0{\times}10^5\;CFU/g$) in the samples. Mesophilic bacteria and anaerobic bacteria were present in average numbers ($10^3-10^5\;CFU/g$). Spore-forming bacteria and coliforms were not detected below detection limit. Yeast and molds were detected at $2.2{\times}10^1-7.8{\times}10^2\;CFU/g$ in the raw beef. Ten samples of raw beef were analyzed for the presence of pathogenic bacteria. Bacillus cereus was isolated from sample B, G, and H. The B. cereus isolates from raw beef samples were identified with 99.8% agreement according to the API CHB 50 kit.

• 한국환경보건학회지
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• 제29권1호
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• pp.19-27
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• 2003

Coliforms is currently being used as the standard of environmental water qualify to evaluate the level of source water quality especially condition of fecal contamination. However, not properly applied to water quality management. So in this study, in addition to Coliforms, fecal contamination indicator bacteria turk at Feral Coliforms(FC), E. coli, Fecal streptococci(FS), Clostridium and environmental parameters related with it's distribution were investigated on a monthly basis in 6 water intakes of Han River. The mean of BOD, DO, SS and pH, benchmarks of source water management were maintained the second grade of environmental water quality standard applied to Han River but Coliforms exceeded it. Distribution of Coliforms ranged from 1.0×10¹ to 2.7 10/sup 5/ CFU/ml, FC ranged from ND to 5.3×10¹ CFU/ml, E. coli ranged from ND to 9.2×10¹ CFU/ml, FS ranged from ND to 2.5×10¹CFU/ml, they were steepy rise on July and August in common when rainfalls was heavy and water temperature was high, but Clostridium perfringens ranged from 1.7×10¹to 1.7×10¹CFU/ml not fluctuate by month. Statistical analysis of sampling data showed that most significant correlations occurred among FC and Coliforms(r = 0.840), E. coli(r = 0.792), FS(r = 0.687) and environmental parameters(temperature, turbidity, SS, rotor were all r > 0.60) while no significant correlation was observed between ammonia generally recognized fecal contamination indicator and bacteria. Identification of the coliforms showed that Enterobacter, Klebsiella, Citrobacter were comprised of 32%, 24%, 16% respectively, and E. coli were 7% of it. while E. coli was made up 85.9% of FC. The mean value of FC/Coliforms ratio, 5.2(0.1-42) were higher in Amsa, Guui than Jayang. Fecal coliforms, as those are able to reflect more particularly the extent of the fecal contamination, were considered useful in deciding the level of water treatment while monitoring the fecal contamination from the source of water supply. Therefore, it is expected that the water quality is going to be managed more efficiently by using fecal coliforms supplementarily to total coliforms which are current standard item of water-quality environment.

• 한국환경보건학회지
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• 제47권2호
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• pp.182-191
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• 2021

Objective: This study was performed to detect indicator bacteria in drinking spring water samples in Gwangju City and to identify their genus using the VITEK-II system. Methods: The subjects were ten drinking spring water sites in Gwangju. Samples of spring water were taken every month from September 2019 to August 2020. We analyzed for the indicator bacteria Yersinia and microorganisms isolated from the spring water. Result: According to the research results on indicator bacteria, general bacteria in st1-st7 with sterilization facilities in the spring and summer were investigated in the range of 0-2 CFU/mL and 0-12 CFU/mL. In st9, where a sterilization facility was not installed, the most general bacteria were detected (160 CFU/mL). Total coliform and fecal coliform showed unsatisfied rates of 16.7 and 11.1% in spring and 14.7 and 11.8% in summer, respectively. The unsatisfied rates of total coliform for the designated and non-designated spring water facilities were 3.8 and 47.1%, respectively, and for the fecal coliform group they were 2.5 and 35.3%. The difference was confirmed according to the presence of a sterilization facility. Yersinia spp. was not detected in all drinking spring water. Forty-one strains in 25 species were isolated from ten sites. The results classified as major dominant species are Pseudomonas spp. 14.6%, Pantoea spp. 9.8%, Serratia spp. 9.8%, Acinetobacter spp. 9.8%, Citrobacter spp. 7.3%, Bordetella spp. 7.3%, Delftia spp. 4.9%, and Enterobacter spp. 4.9%. Conclusions: Based on the result that various species derived from fecal pollution and artificial pollutants were detected in the non-specified public spring water facilities that many people use, the facilities need institutional complements such as continuous management or complete shutdowns.

• 한국환경보건학회지
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• 제32권1호
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• pp.77-88
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• 2006

This study were conducted to investigate the microbial contamination level in 5 tomato farms in Western Gyeongnam. A total of 130 samples was examined for sanitary indicator bacteria, such as aerobic plate count (APC), coliforms, and Escherchia coli, and pathogenic bacteria such as E. coli O157:H7, Salmonella spp., Staphylococcus aureus, and Listeria monocytogenes. APC and coliform count ranged $0\~6.62\;and\;0\~4.52 log_{10}\;CFU/(ml,\;g,\;100\;cm^2,\;hand)$, respectively, and $32.5\%$ were contaminated with E. coli. Especially, most of the samples from employees are high as above $4.0\;log_{10}\;CFU/(ml,\;g,\;100\;cm^2,\;hand)$ in APC. S. aureus, detected at $10.7\%$, was found in employees' hands, irrigation water, and hydroponic solution. whereas E. coli $O157:H7$, Salmonella spp, and L. monocytogenes were not detected. These results will provide fundamental microbiological information for introduction of good agricultural practice (GAP)system in tomato farms.

• 한국물환경학회지
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• 제22권3호
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• pp.527-533
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• 2006

Tetracycline is one of the mostly used antibiotics around the world. The purpose of this study was to evaluate the fate of two different types of tetracycline resistant bacteria in biological wastewater treatment plants. Tetracycline resistant enterics and heterotrophic bacteria were monitored under two different lab-scale experimental conditions. Tetracycline resistant enteric bacteria showed the lower percentages of total enteric bacteria and net specific growth rate in the monitored activated sludge system as compared to tetracycline resistant heterotrophic bacteria. Therefore, total enterics, potentially E.coli, might not be the best indicator microorganism for evaluating the antibiotic resistant bacteria in biological wastewater treatment plant.

• 한국물환경학회지
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• 제26권1호
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• pp.10-18
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• 2010

Water quality and the distribution of ammonia oxidizing bacteria were characterized in constructed wetland of Shihwa lake. Both physico-chemical parameters and fecal indicator microorganisms including total coliforms, E.coli, Enterococcus spp. were measured. In addition, denaturant gradient gel electrophoresis (DGGE) was carried out after PCR amplification of amoA gene from input, output, and wetland sites of the Banwol, Donghwa, and Samhwa stream in Shihwa lake area. Physico-chemical parameters were in proper range for typical nitrifying bacteria to grow and perform their biological activities. Average concentrations of fecal indicator microorganisms of wetland samples were lower than those of input sites. These results suggested that microbial water quality improved by the process of constructed wetland. According to phylogenetic information obtained from DGGE from study sites, distribution of nitrifying bacteria from each of input, output, and wetland were generally distinctive one another. In addition, distribution of nitrifying bacteria between Banwol and Donghwa streams showed higher similarity (52.6%) than this of Samhwa stream (15.2%). These results indicated that characteristics of ammonia oxidizing bacteria in Samhwa were unique in comparison with those of Banwol and Donghwa stream.

• 한국환경보건학회지
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• 제39권6호
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• pp.513-521
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• 2013

Objectives: This study was performed in order to detect indicator bacteria in drinking spring water (DSW) samples in Seoul Metropolitan City, and to identify their genus through 16S rRNA sequencing and then assessing the genetic relation of their strains. Methods: For indicator bacteria detection and identification of total coliforms, we analyzed DSW between the spring and summer seasons. In particular, DSW samples were chosen from sites repeatedly found unsatisfactory in recent years. Results: Heterotrophic plate counts of DSW in the spring and summer season were investigated in the range of 0-550 and 0-800 CFU/mL, respectively. Total coliforms of these were 0-1,900 and 0-2,100 CFU/100mL, fecal coliforms were 0-600 and 0-550 CFU/100mL, and Escherichia coli were 0-7 and 0-326 MPN/100mL. The detection ratio of fecal pollution indicators and that of fecal coliforms increased to 58.6% in the summer from 12.5% in the spring and Escherichia coli increased to 51.4% from 4.7%. As a result of genetic analysis on the isolated bacteria, the genus of total coliforms was classified in the order of Enterobacter spp. 12.7%, Serratia spp. 7.3%, E. hermanii 6.4%, Rahnella spp. 5.5%, Hafnia spp. 4.5%, Escherichia coli 3.6%, Klebsiella spp. 3.6% in the spring season. In the summer season, it was classified in order of Klebsiella spp. 16.6%, Enterobacter spp. 13.0%, Escherichia coli 11.0%, Serratia spp. 8.6%, Raoultella spp. 7.0%, Kluyvera spp. 5.6% and Citrobacter spp. 3.0%. Conclusions: The increase of fecal pollution in summer indicates that special attention to drinking DSW is required.

• 한국미생물·생명공학회지
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• 제21권3호
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• pp.288-292
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• 1993

An agar medium(HY) was developed to detect the urease-producing lactic acid bacteria. HY medium was prepared with the addition of tryptone, glucose and tween 80 to the supernatant of autoclaved skim milk and yeast extract mixture. There was no difference in eumeration of lactic acid bacteria between the HY and commercial media, such as M17, MRS and BCP agar. The urease activity of Streptococcus salivarius subsp. thermophilus was detected on the HY agar medium contained urea by the color change of bromocresol purple as the pH indicator, but not on the commerical agar media. Furthermore, it was succeeded to screen the urease activity of bacteria in skim milk used as a raw material in dairy product manufacture. Therefore, HY medium was proved to be suitable for the screening of urease-producing lactic acid bacteria.

• 한국수산과학회지
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• 제56권5호
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• pp.721-727
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• 2023

This study was conducted to evaluate the level of microbial contamination in smoked salmon products sold in hypermarkets in major metropolitan cities in Korea. Listeria monocytogenes is the primary cause of smoked and raw salmon product recalls. Here, we used L. monocytogenes as a bacterial hygiene indicator and investigated the microbial contamination level of frozen/refrigerated smoked salmon products collected from hyper markets. Contamination levels were analyzed by seasons, manufacturers, and consumption regions. For hygiene indicator bacteria, total bacteria count, coliforms, and Escherichia coli were examined according to the food code established by the Ministry of Food and Drug Safety, and polymerase chain reaction (PCR) was performed to detect Listeria sp. The highest contamination level was observed in spring in Busan among five consumption regions. Listeria was detected at a level of 2.1% among all samples collected. And especially L. monocytogenes was detected in two cases from the samples collected from Daegu and Daejeon. Sanitary standards and specifications should be established according to the contamination level of smoked salmon products investigated in this study, and continuous monitoring is necessary.

• Ocean Science Journal
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• 제41권2호
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• pp.113-119
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• 2006

Seventeen lactic acid bacterial strains (LAB) were isolated using MRS agar medium from Jeotgal, a Korean fermented food, purchased at the Jukdo market of Pohang. To identify the strains isolated, they were tested by examining their cell morphologies, gram-staining, catalase activity, arginine hydrolase activity, D-L lactate form and carbohydrate fermentation. According to the phenotypic characteristics, three strains were tentatively identified as Lactobacillus spp., ten were Enterococcus spp. (or Streptococcus spp., or Pediococcus spp.) and the rest were Leuconostoc spp. (or Weissella spp.). Five strains among 17 were chosen by preliminary bacteriocin activity test. Four bacterial strains which inhibited both indicator microorganisms were identified by 16S rRNA sequencing. The results are as follows; Leuconostoc mesenteroides (HK 4), Leuconostoc mesenteroides (HK 5), Leuconostoc mesenteroides(HK 11), Streptococcus salivarius(HK 8). In order to check LAB which are showing a high survival rate in gut, we investigated three strains inhibiting both indicator microorganisms in artificial gastric acid and bile juice -all except HK8. The three strains mentioned above grew in extreme low acid conditions.