• Korean Journal of Veterinary Service
• /
• v.23 no.2
• /
• pp.105-112
• /
• 2000

This survey was conducted to evaluate the microbiological quality of raw beef and pork products from January to December in 1999. A total of 107 beef and 157 hog carcasses were collected from two abattoirs located in Seoul. The result showed that beef carcasses had an average bacterial loading around 139,000 bacteria/$\textrm{cm}^2$ of carcass surface, indicating a little bit higher count than the results reported in USA and Australian meat. However, overall hygienic status was found to be acceptable for all examined carcasses because 84.4% of product rated excellent, good or acceptable comparable to USA of 91.6% and Australia of 88%. The analysis of data on overnight-chilled to weekend-chilled carcasses indicated that the microbiological growth occurred in the chiller during the weekend chill with increases in total viable count from 130,000cfu/$\textrm{cm}^2$ to 400,000cfu/$\textrm{cm}^2$. Qualitative testing for escherichia coli, EC + MUG was used as a most probable number (MPN) method along with the petrifilm method. The average of MPN/$\textrm{cm}^2$ of E coli biotype 1 was 29MPN/$\textrm{cm}^2$ for beef carcasses and 1,100 MPN/$\textrm{cm}^2$ for hog carcasses, respectively. However, 41% of beef and 16.3% of hog carcasses were shown to be less than < 3 MPN/$\textrm{cm}^2$ in E coli biotype 1 examination. Although salmonella enteritis, S typhimurium and E coli O157:H7 were all negative, listeria monocytogenes was recovered from only one hog surface samples of the 89 carcasses tested.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.41 no.11
• /
• pp.1-7
• /
• 2004

We propose multistage parallel nulling (MPN) partial parallel interference cancellation (PPIC) receiver for downlink multiple-input multiple-output (MIMO) multicarrier (MC)-code division multiple access (CDMA) systems. Though the V-BLAST is a popular MIMO receiver, it shows error floor for multiuser downlink MIMO MC-CDMA systems. The proposed MPN-PPIC receiver does not produce error floor for multiuser case, and achieves substantial performance gains with multistage processing. For single user case, the proposed method also surpasses the V-BLAST receiver with multistage processing for MIMO MC-CDMA systems with chip level interleaving. The system performance of the proposed MPN-PPIC receiver is evaluated through computer simulations.

• Korean Journal of Microbiology
• /
• v.53 no.1
• /
• pp.9-19
• /
• 2017

We studied soil composition, $N_2O$ production, a number of denitrifying bacteria, community structure and T-RFLP patterns of denitrifying bacteria dependent on agricultural methods with the change of seasons. Analyses of the soil chemical composition revealed that total carbon and total organic carbon contents were 1.57% and 1.28% in the organic farming soil, 1.52% and 1.24% in the emptiness farming soil, and 1.40% and 0.95% in traditional farming soil, respectively. So, the amount of organic carbon was relatively high in the environment friendly farming soils than traditional farming soils. In case of $N_2O$ production, the amount of $N_2O$ production was high in May and November soils, but the rate of $N_2O$ production was fast in August soil. The average number of denitrifying bacteria were $1.32{\times}10^4MPN{\cdot}g^{-1}$ in the organic farming soil, $1.17{\times}10^4MPN{\cdot}g^{-1}$ in the emptiness farming soil, and $6.29{\times}10^3MPN{\cdot}g^{-1}$ in the traditional farming soil. It was confirmed that the environment friendly farming soil have a larger number of denitrifying bacteria than the traditional farming soil. As a result of the phylogenetic analyses, it was confirmed that six clusters were included in organic farming soil among total 10 clusters. And the result of PCA profile distribution of T-RFLP pattern on agricultural methods, the range of distribution showed wide in the organic farming method, relatively narrow in the conventional farming method, and middle in the emptiness farming method. Therefore, we could concluded that the distribution and the community structure of denitrifying bacteria were changed according to the agricultural methods and seasons.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.45 no.1
• /
• pp.11-16
• /
• 2012

In coastal areas that are affected by continuous, seasonal or occasional pollution sources, bivalves accumulate biological contaminants such as pathogenic bacteria. We investigated the effect of natural seawater relaying and electrolyzed seawater depuration on the bacteriological quality of artificially contaminated oysters Crassostrea gigas and short-necked clams Ruditapes philippinarum to suggest an alternative method of shellfish sanitation control.When artificially contaminated oysters and short-necked clams (fecal coliform level 1,700 MPN/100 g) were relayed into a sea area of safe bacteriological water quality, the fecal coliform level dropped to below 110 MPN/100 g after 1 day. The bacteriological quality of oysters and short-necked clams that are contaminated at a fecal coliform level of 1,700 MPN/100 g could be improved, and become appropriate for raw consumption by a single day relay under proper environmental conditions. When artificially contaminated oysters (fecal coliform level 330 MPN/100 g) were depurated with electrolyzed seawater, 94% of fecal coliform was eliminated after 12 h and fecal coliform was undetectable after 24 h. After 24 h depuration with electrolyzed seawater, the fecal coliform level of short-necked clams with initial fecal coliform of 2,400 MPN/100 g was below 20 MPN/100 g. However, the fecal coliform level of short-necked clams with initial fecal coliform of 17,000 MPN/100 g was relatively high, at 790 MPN/100 g, even after 24 h of depuration with electrolyzed seawater, because of the repeated cycle of excretion and accumulation of fecal coliform in shellfish tissue under the closed depuration environment. Such natural seawater relaying and electrolyzed seawater depuration can be restrictively applied to improve or secure the bacteriological quality of oysters and short-necked clams in accordance with safety levels for bivalves for raw consumption.

• Journal of Korean Society of Environmental Engineers
• /
• v.22 no.3
• /
• pp.417-427
• /
• 2000

The substrate metabolism and bacterial population in an anaerobic digestion with the submerged separation membrane were investigated by using a laboratory-scale reactor at the hydraulic retention time(HRT) 1.0 and 0.5 day. The removal efficiencies of carbohydrate at the HRT 1.0 and 0.5 day were 99.8~99.9% and 98.0~99.6%, respectively. After the 58 days, the mixed liquor volatile suspended solids(MLVSS) concentration at the HRT 1.0 and 0.5 day were approximately 6,050 and 7,750 mg/L, respectively. According to the measurement by the most probable number(MPN) method, the numbers of acidogenic bacteria, $H_2$-utilizing and acetate-utilizing methc.nogenic bacteria were found to be $10^9$, $10^7{\sim}10^8$ and $10^6{\sim}10^8MPN/mL$, respectively. The composition of $CH_4$ in the produced gas was 46~50%. It is suggested that sulfate-reducing bacteria $10^7{\sim}10^8MPN/mL$ play an important role in producing $H_2$ and acetate in sulfate-depleted environment.

• Korean Journal of Food Science and Technology
• /
• v.49 no.5
• /
• pp.532-537
• /
• 2017

The purpose of this study was to examine the best cooking condition to decrease 4'-O-methylpyridonxine (MPN, ginkgotoxin) and increase the antioxidative effect. We also examined the change in color of ginkgo biloba seeds after different cooking methods and times. MPN content was decreased with an increase in the cooking time. For the reduction of MPN content, the most efficient cooking method was pan-frying. In particular, MPN content was largely reduced after 8 min of pan-frying. 1,1-Diphenyl-2-picrylhydrazyl radical scavenging activity and total flavonoid content were increased after 11 min of pan-frying and this level was maintained until 14 min. The total phenolic compound content was maintained for up to 30 min by steaming and 11 min by pan-frying. Therefore, the optimum condition was established by pan-frying from 8 to 11 min.

• Journal of Animal Environmental Science
• /
• v.4 no.2
• /
• pp.137-147
• /
• 1998

This study was carried out to find deodorization effect of swine-slurry by addition of phototrophic bacteria(PTB). The pilot-scale reactors operation conditions was designed by the inoculum amounts of PTB and light-conditions. Treatment conditions was divided into 3 types; 106 MPN/ml$.$Dark(T-1), 108 MPN/ml$.$Dark(T-2), 108 MPN/ml$.$Natural light(T-3). The changes of the concentration of volatile fatty acids(VFAs), hydrogen sulfide(H2S), ammonia (NH3) and odor intensity were analyzed during the treatment period(35 days). From results of this study, the maximum intensity of odor in the headspace of the reactor T-1 was 4.82 and T-2, T-3 was 2.63, respectively. In swine-slurry of reactors used, it almost took 10 days until to be stabilized with solid and liquid phase. Intensity of odor in headspace was mainly derived from the liquid phase. The PTB inoculum method to swine-slurry was very effective in reduction of VFAs, H2S and Sulfate-reducing bacteria(SRB) concentration. Expecially, It was interested in reverse growth behaviour of SRB and PTB in these conditions.

• Journal of Korean Society on Water Environment
• /
• v.16 no.4
• /
• pp.541-554
• /
• 2000

Experimental study of anaerobic digestion process combined with and without the submerged separation membrane was investigated by using laboratory-scale reactor at the hydraulic retention time of 0.5 day and 1.0 day. The removal efficiencies of carbohydrate at the digester without and with membrane were 84.4 to 86.8 % and 99.6 to 99.7 %, respectively, and the methane gas recovery efficiencies were 0.4 to 1.2 % and 12.3 to 28.7 %. According to the measurement by the most probable numbers method. the numbers of various groups of bacteria in the digesters with membrane were enumerated in the following ranges ; acidogens : $1.7{\times}10^9$ to $5.0{\times}10^9MPN/m{\ell}$, homoacetogens : $5.0{\times}10^7$ to $2.4{\times}10^8MPN/m{\ell}$, $H_2$-utilizing methanogens : $1.3{\times}10^7$ to $9.2{\times}10^8MPN/m{\ell}$, and acetate-utilizing methanogens : $2.3{\times}10^6$ to $2.0{\times}10^8MPN/m{\ell}$. The number of methanogens at the digester with membrane increased by approximately $10^2$ to $10^4$ times in comparison with that of the digester without membrane.

• Journal of Life Science
• /
• v.13 no.2
• /
• pp.197-205
• /
• 2003

We detested waterborne enteric viruses from the raw water and tap water in Busan metropolitan city by the total culturable virus assay of EPA standard method. According to the results of survey from July 2001 to November 2002, thirteen out of twenty one in raw water samples were positive (61.9%) for enteric viruses and all of the treated water and tap water samples were negative. The enteric viruses in raw water were mainly distributed through the summer to the earl y winter, suggesting the seasonal characteristics of virus distribution in water The titer of enteric viruses per 100 liters of the raw water was ranged from 1.92 to 9.70 MPN by TCVA-MPN program. The isolated viruses were identified as either human poliovirus type 1 or enteroviruses by the immunofluorescent assay.

• Journal of environmental and Sanitary engineering
• /
• v.4 no.2 s.7
• /
• pp.47-59
• /
• 1989

In order to investigate the bacteriological contamination of water in Han river, the survey was carried out in eight reservoirs of Seoul water supply during the period from January to December in 1985. 1. The counts by means of total bacteria in eight reservoirs by standard plate count method were as follows: $7.7\times10^2$ per ml in Paldang reservior, $9.6\times10^3$ per ml in Gueiri, $8.4\times10^4$ per ml in Doogdo, $1.6\times10^6$ per ml in Bogwang, $2.5\times10^6$ per ml in Noryangjin, $2.2\times10^6$per ml in Seon yoo, $5.9\times10^6$ per ml in Yungdeungpo and $1.9\times10^7$per ml in Gayang. 2. The average counts of total coliform in eight reservoirs by MPN method were as follows : $2.4\times10$ per 100 ml in Paldang, $5.6\times10^2$ per 100 ml in Gueiri, $2.3\times10^3$ per 100 ml in Doogdo, $5.1\times10^4$ per 100 ml in Noryang-jin, $1.2\times10^5$ per 100 ml in Bogwang, $6.2\times10^4$ per 100 ml in Seonyoo, $1.1\times10^5$ per 100 ml in Yungdeungpo and $2.8\times10^5$ per 100 ml Gayang. 3. The counts by means of fecal coliform in eight reservoirs by MPN method were as follows : non detection per 100 ml in Paldang, 5.2 per 100 ml in Gueiri, $1.2\times10^2$ per 100 ml in Doogdo, $1.6\times10^3$ per 100ml in Bogwang, $2.0\times10^3$per 100ml in Noryangjin, $6.6\times10^2$ per 100ml in Seonyoo, $1.2\times10^3$ per 100 ml in Yungdeungpo and $2.5\times10^3$per 100 ml in Gayang. 4. The counts by means of fecal streptococci in eight reservoirs by MPN method were as follows: non detection per 100 ml in Paldang and Gueiri, $6.9\times10$ per 100 ml in Doogdo, $3.2\times10^2$ 102 per 100 ml in Bogwang, $2.9\times10^2$ per 100 ml in Noryangjin, $3.0\times10^2$ per 100 ml in Seonyoo, $4.0\times10^2$ per 100 ml in Yungdeungpo and $14\times10^3$ per 100 ml in Gayang. 5. The counts means of pseudomonas aeruginosa in eight reservoirs by MPN method were as follows; non detection per 100 ml in Paldang, 2.4 per 100 ml in Gueiri, $1.5\times10$ per 100 ml in Doogdo, $2.0\times10$ per 100ml in Bogwang,$6.2\times10$ per 100mI in Noryangjin, $2.1\times10$ per 100ml in Seonyoo, $6.4\times10$ per 100mI in Yungdeungpo and $7.1\times10$ per 100ml in Gaynag.