• Proceedings of the Korean Society of Life Science Conference
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• 2007.10a
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• pp.28-28
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• 2007

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• Journal of the korean veterinary medical association
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• v.39 no.8
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• pp.710-716
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• 2003

• Korean Journal of Veterinary Service
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• v.35 no.4
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• pp.295-305
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• 2012

The aim of this study was to isolate microorganisms from half milk samples of dairy goats by California mastitis test (CMT) during the lactation period and to further investigate the susceptibility of isolated organisms to antimicrobial drugs. From a total of 235 half milk samples with CMT scores of 2 or above from 366 dairy goats distributed throughout Jeonnam province, microorganisms were isolated from 198 (83.5%) samples either singly (99.0%) or in combination (1.0%). The most prevalent microorganism was the coagulase-negative Staphylococcus spp., (44.4%, n=88) followed by Staphylococcus aureus (24.2%, n=48), Escherichia coli (11.1%, n=22) and Streptococcus spp. (7.6%, n=15). Isolated bacteria also included Bacillus spp. (2.5%, n=5), Pseudomonas spp. (2.5%, n=5), Micrococcus spp. (1.5%, n=3), Corynebacterium spp. (1.5%, n=3), Enterococcus facium (1.0%, n=2), Morganella morganii (0.5%, n=1) and Streptococcus agalactiae (0.5%, n=1). During the summer season, a high prevalence of all microorganisms were observed in which Staphylococcus spp. (30.8%), Escherichia coli (8.6%), and Streptococcus spp. (5.6%) were among the most prevalent bacteria isolated. Staphylococcus spp. was also shown to be high in the winter (21.7%). In most samples, the presence of bacterial pathogens in goat milk led to the increase in the total somatic cell count (SCC). Most of the half milk samples of dairy goats with bacterial contamination showed SCC of ${\geq}1{\times}10^6cells/ml$ (90.4%). Minor pathogens (11.4%) were more detected from milk samples with SCC of < $1{\times}10^6cells/ml$ than major pathogens (4.1%), while the major pathogens tended to be higher from samples with SCC of ${\geq}3{\times}10^6cells/ml$. Susceptibility of these bacteria to 12 antimicrobial agents was tested by the Kirby-Bauer disc diffusion method. Results indicated that more than 90% of bacteria isolated from CMT 2+ dairy goat half milk samples were susceptible to trimethoprim/sulfamethoxazole, amoxicillin/clavulanic, enrofloxacin and cephalothin while they were resistant to tetracycline (44.7%).

• Korean Journal of Clinical Laboratory Science
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• v.47 no.2
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• pp.59-64
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• 2015

Lactic acid-producing bacteria such as Lactobacillus spp. function to ferment carbohydrates and produce ATP. Such Lactobacillus spp. are used for the production of commercial yogurts. Lactobacillus spp. are beneficial to the intestinal tract, and Lactobacillus acidophilus-containing yogurts have received considerable attention because of their preventive effects against early-stage cancer of the large intestine. In this study, lactic acid-producing bacteria were cultured from three different groups: commercial solid yogurt (for eating), commercial liquid yogurt (for drinking), and Lactobacillus acidophilus-containing yogurt. We first determined the optimum culture conditions for Lactobacillus spp. and then analyzed turbidity and pH in order to compare the growth abilities and lactic acid-production capacities among the groups. Finally, high-performance liquid chromatography was used to measure the lactic acid content in the culture supernatants, and the antibacterial activities against Staphylococcus aureus and Escherichia coli were compared among the three groups. The optimum culture conditions for Lactobacillus spp. were MRS medium at $25^{\circ}C$, for 24 h. The highest turbidity was found in L. acidophilus-containing yogurt, followed by liquid yogurt and solid yogurt. Similarly, the highest lactic acid production ability was found in L. acidophilus-containing yogurt, followed by liquid yogurt and solid yogurt. Culture supernatants from the three groups did not show any antibacterial activity towards S. aureus; however, supernatants derived from L. acidophilus-containing yogurt resulted in a 1.8 mm inhibitory zone against E. coli in a paper disk diffusion test. These results revealed the high level of lactic acid-production capacity and antibacterial activity in L. acidophilus-containing yogurt.

• Journal of Food Hygiene and Safety
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• v.22 no.3
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• pp.151-158
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• 2007

Among 68 strains of lactic acid bacteria (LAB) isolated from Dongchimi, a strain K11 was selected due to its bactericidal activity against Escherichia coli O157 The strain K11 was identified as Lactobacillus plantarum, based on physiological and biochemical characteristics. In the late exponential phase, La. plantarum K11 showed maximum bacteriocin activity (12,800 BU/mL) and maintained until the early stationary phase. The bacteriocin activity was completely inactivated by all the proteolytic enzymes such as pepsin, protease, proteinase K, papain, chymotrypsin, and trypsin, but the activity was not affected by catalase, a-amylase, lysozyme, and lipase, suggesting proteinaceous nature of the bacteriocin. Additionally, this activity was not affected in the pH range from 3.0 to 9.0 and under storage conditions like 30 days at -20,4, or $25^{\circ}C$. Although the bacteriocin activity was absolutely lost after 15 min treatment at 121, it was relatively stable at $70^{\circ}C$ for 60 min or $100^{\circ}C$ for 30 min. The activity was disappeared by treatment with acetone, benzene, ethanol, or methanol, but it was not affected by treatment with chloroform or hexane. The antibacterial activity of the bacteriocin was good against some LAB including Lactobacillus spp., Enterococcus spp., and Streptococcus spp., but not against food-borne pathogens such as Bacillus spp., Listeria spp., and Staphylococcus spp. as well as yeasts and molds. Especially, some intestinal bacteria such as Enterobacter aerogenes and E. coli were significantly affected by the bacteriocin of La, plantarum K11. Furthermore, the addition of 640 BU/mL resulted in the complete clearance of E. coli O157 after 10 hr.

• Journal of fish pathology
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• v.20 no.3
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• pp.229-235
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• 2007

Cell number of Vibrio spp. was examined for the surface and bottom sea water harvested from the 9 stations in the Jeonam Archipelago Marine Ranching Ground in 2006～2007. Species population composition and dominant species were analyzed as well. The largest number of Vibrio spp. was detected in summer (June, 2007) among the 4 seasons with the surface and bottom sea water samples of 5.4～93.2 cfu㎖-1 and 1.0～53.1 cfu㎖-1. respectively. In winter (January, 2007), Vibrio spp. was not detected at all except that one station from which 0.2 cfu㎖-1 of Vibrio spp. was counted in the surface sea water sample. Cell numbers were 0～11.9 cfu㎖-1 and 0～8.3 cfu㎖-1, respectively, in the surface and bottom sea water samples retrieved in spring (April, 2007), and the corresponding sea water samples in autumn(November, 2006) were contaminated with 0.1～21.4 cfu㎖-1 and 0～2.9 cfu㎖-1, respectively. Species population composition of Vibrio spp. was found to be V. parahaemolyticus, V. alginolyticus and V. cholerae non-01 among which V. parahaemolyticus and V. alginolyticus were dominant in all seasons. V. alginolyticus was detected from all stations even in the winter season indicating that this species seems to be less temperature dependent than the other Vibrio spp..

• Food Science and Preservation
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• v.18 no.1
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• pp.98-102
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• 2011

We evaluated microbial inactivation in chicken cage litter, to ensure microbial safety, using aqueous chloride dioxide. Contamination by coliforms, Escherichia coli, Listeria spp., yeasts and molds, total aerobic bacteria, and Salmonella spp. was detected in fresh cage litter, and microbial populations increased if litters were repeatedly used. Aqueous $ClO_2$ treatment (500 ppm) significantly decreased the populations of coliforms, E. coli, Listeria spp., yeasts and molds, total aerobic bacteria, and Salmonella spp. in all litter samples tested. In particular, aqueous $ClO_2$ treatment on fresh litter reduced the initial populations of coliform, E. coli, Listeria spp., yeasts and molds, and total aerobic bacteria by 4.47, 1.29, 1.23, 3.24, and 5.2 log CFU/g, respectively. In addition, when litters used for 1 and 5 weeks were tested, treatment significantly reduced microbial populations. The results suggest that aqueous $ClO_2$ treatment is useful to reduce microbial hazards in chicken cage litter and to improve the microbial safety of slaughtered chickens.

• Korean Journal of Ecology and Environment
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• v.37 no.4 s.109
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• pp.385-393
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• 2004

The herbivorous rotifers community (Brachionus spp.) and population dynamics of the predator rotifer (Asplanchna spp.) in three tributaries (Kumho R., Nam R., and Hwang R.) of the Nakdong River were evaluated on biweekly intervals from Jan. 2001 and Dec. 2002. High abundance of the herbivorous rotifers (peak density: - ca.>1000 Ind. $L^{-1}$) was observed from two tributaries (Kumho R. and Nam R.) during the spring and fall seasons, respectively. The high peaks of herbivorous rotifers were not evident in one tributary (Hwang R.). Among the herbivorous rotifers, brachionid rotifers (Brachionus spp. consisting of 7 species) were the characteristic rotifer community in this study. Brachionus spp. tended to occur together with the other perennial species, Asplanchna. Asplanchna was also present while two species of B. angularis and B. calyciflorus were highest in density. Subsequently, two populations (B. angularis and B. calyciflorus) rapidly declined, becoming rare after high peaks of Asplanchna occurred, except in one tributary (Hwang R.). We found community shifts in rotifer groups in mid-spring and mid-fall at the study site. The Asplanchna population could be appeared to play an important role in regulating the rotifer community and total plankton biomass in spring and fall at high trophic levels.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.1
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• pp.9-16
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• 1996

In order to understand microbial ecosystem in the fast china sea and Yosu coastal sea horizontal distributions of bacterial flora, Vibrio spp., coliform group, temperature, and salinity in this sea area, were studied 42 sampling stations during 6th-l4th August, 1992. From the results, salinity and temperature were $24.64\~33.78\%_{\circ}$ and $22.53\~29.18^{\circ}C$, respectively. As the open sea far from land goes on, salinity became low while temperature became high. Viable cell counts of bacteral flova, Vibrio spp., and roliform group in Yosu coastal sea water were $1.0\times10^2\~3.0\times10^4/ml,\;0.2\times10\~9.0\times10^3/ml,\;and\;0.3\times10\~3.0\times10^3/ml$ while those of these in the open sea water were $0.4\times10\~2.0\times10^3/ml,\;0.8\times10\~3.0\times10/ml,\;and\;0.9\times10\~1.3\times10/ml$, respectively.

• Korean Journal of Food Science and Technology
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• v.25 no.5
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• pp.582-588
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• 1993

In order to investigate the effects of food materials toward the growth of Bifidobacterium spp. and Clostridium perfringens which have great influences on the intestinal physiology of human, 162 kinds of foodstuffs and foods were collected. Among their extracts, 31 samples showed the inhibitory effects against the growth of B. bifidum and C. perfringens by agar diffusion method. Especially, the methanol extracts of Caltha palustris, Deonjang, onion, mustard and potato inhibited the growth of C. perfringens, while they did not remarkably inhibit other intestinal bacteria including Bifidobacterium spp. By the cultivation of faecal inoculum in the 1 %(v/v) extract broths of Caltha palustris, onion and mustard, population of Bifidobacterium spp. increased by 10 order and that of C. perfringens decreased. ${\beta}$-glucuronidase activities and indole amounts in the cultures of onion and mustard extracts were lower than those of the control culture and ${\beta}-glucosidase$ activities were not detected in the cultures of onion and Doenjang extracts.