• 치위협보
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• s.93
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• pp.1-12
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• 2005

• 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.

• Journal of Environmental Science International
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• v.10 no.3
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• pp.247-252
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• 2001

This study was performed to evaluate the inactivation and microbial regrowth of heterotrophic and nitrifying bacteria using chloramine as a secondary disinfectant for drinding water distribution system. Three sets of the three reactors filled with the $Cl_2/NH_3-N$ ratio of 3:1, 4:1, and 5:1 were used in these experiments. Chloramine concentration were applied to each set of the reactors with $1mg/\ell$,\;2mg/\ell\;and\;3mg/\ell$, respectively. For the set with elapsed time and reached to zero level after 7 days. Heterotrophic bacteria remarkably increased and nitrification through the experimenatal period (21 day). Furthermore the regrowth of heterotrophic bacteria and nitrification were not found. More than $2mg/\ell$ of chloramine with $Cl_2/NH_3-N$ ratio of 3:1, the nitrification could be inhibited by 2 days of contact time.

• Food Industry And Nutrition
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• v.7 no.3
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• pp.39-43
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• 2002

본 연구에서는 전통적으로 한방에서 성장 촉진을 위하여 사용된 녹각, 우슬, 구기자, 두충, 오미자 및 용안 등의 한약재 추출물과 액상칼슘을 각각 첨가하여 4구간의 빵을 제조하여 품질 특성을 비교 분석하였다. 빵의 물성을 측정한 결과, strength, hardness는 한약재 추출물과 액상칼슘의 첨가량이 많을수록 높아지는 경향을 나타냈었으며 cohesiveness, springiness, gumminess 및 brittleness는 감소하는 경향으로 나타났다. 빵의 내부와 표면의 색도(L,a,b)는 첨가량에 따라 차이가 있었으며 저장 4일째에 각각 변화 정도의 차이가 있었다. $37^{\circ}$ 에서 4일간 저장 후 일반세균은 무첨가구 $15\times10^3CFU/g$에 비하여 한약재 추출물 및 액상칼슘 첨가량이 많은 구간에서는 급격히 감소하여 보존성이 높게 나타났다. 관능적 특성은 실험구간에 따른 유의적 차이는 크게 나타나지 않았으며, 각각의 실험구간에 따른 칼슘함량을 비교 분석한 결과. 한약재 추출물과 액상칼슘이 많은 구간에서 높게 나타나는 경향이었다. 이상의 결과를 바탕으로 성장촉진 한약재 및 액상칼슘을 기능성 소재로서 제빵에 활용 가능할 것으로 생각된다.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.26 no.5
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• pp.446-457
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• 1993

Monthly distribution of marine bacteria and phytoplankton in Suyeong Bay were investigated with laboratory experiment of dominant algal species and bacterial flora. During the periods of study, the highest density of phytoplankton and bacteria occurred in May with the number of $3.3{\times}10^6cells/l$ and $1.93{\times}10^8cells/ml$, respectively. 10 genera of bacteria and 22 genera of phytoplankton were isolated and identified. In May when phytoplankton bloom occurred, dominant species of bacteria were Acinetobacter calcoaceticus($29.1\%$) and Bacillus subtilis($22.9\%$), and dominant species of phytoplankton were Chaetoceros spp.($62.8\%$) and Skeletonema spp. ($19.4\%$). Pseudomonas spp., which was the most abundant bacterial species during the study periods, were rapidly decreased in May. In laboratory studies of culturing bacteria and phytoplankton isloated in May, the growth of Pseudomonas vesicularis seems to be influenced by the concentrations of excretion matter of Chaetoceros spp. To examine the result colsely, the problem of pure isolation for phytoplankton must be solved and more experimental process have to be conducted.

• Research in Plant Disease
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• v.28 no.2
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• pp.69-81
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• 2022

This study was performed to screen the efficacy of antagonistic bacterial isolates from various sources against the bacterial fruit blotch (BFB) causing pathogen (Acidovorax citrulli) in cucurbit crops. In addition, plant growth promoting traits of these antagonistic bacterial isolates were characterized. Two thousand seven hundred ninety-four microorganisms were isolated from the collected samples. Molecular identification revealed two A. citrulli out of 2,794 isolates. In vitro antagonistic results showed that, among the 28 antagonistic bacterial isolates, 24 and 14 bacterial isolates exhibited antagonism against HPP-3-3B and HPP-9-4B, respectively. Antagonistic and growth promotion characterization of the antagonistic bacterial isolates were further studied. Results suggested that, 4 antagonistic bacteria commonly showed both antagonism and growth promotion phenotypes. Moreover, 3 isolates possessed growth promoting activities. Overall results from this study suggests that BFB causing bacterial pathogen (A. citrulli) was suppressed in in vitro antagonism assay by antagonistic bacterial isolates. Furthermore, these antagonistic bacterial isolates possessed growth promotion and antagonistic enzyme production ability. Therefore, data from this study can provide useful basic data for the in vivo experiments which ultimately helps to develop the eco-friendly agricultural materials to control fruit rot disease in cucurbit crops in near future.

• Journal of Life Science
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• v.17 no.11
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• pp.1601-1604
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• 2007

The gene for ${\beta}-agarase$ of an Agarivorans sp. JA-1 was expressed in Bacillus subtilis DB104, 168 and ISW1214 strains for mass-production. Among 3 host strains, B. subtilis ISW1214 secreted the highest amount of recombinant ${\beta}-agarase$ with a specific activity of 201 U/mg and 360 mg of protein into culture broth. This was approximately 130-fold higher than the production in E. coli as an expression host. Recombinant enzyme produced neoagarooligosaccharides such as neoagarohexaose, neoagarotetraose, and neoagarobiose from agar. Produced neoagarooligosaccharides showed antibacterial activities against gram-negative E. coli and gram-positive B. subtilis at a concentration of 1.5%. These data suggest that neoagarooligosaccharides could be an useful preservative for food industry.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.2
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• pp.261-269
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• 2012

In this study, 18 kinds of Korean medicinal herb extracts were examined for anti-microbial activities against pathogenic microorganisms. The methanol (MeOH) extracts from Schizandra chinensis, Rhus javanica and Caesalpinia sappan exhibited antimicrobial activities against most pathogenic microorganisms at concentrations of 5 mg/mL, whereas the other 15 extracts exhibited anti-microbial activities at concentrations of 30 mg/mL. The minimum concentration at which Schizandra chinensis extracts inhibited for S. epidermidis and Bor. bronchiseptica was 0.6 mg/mL. The MeOH extracts from Schizandra chinensis, Caesalpinia sappan, Rhus javanica and Seutellaria baicalensis which had higher anti-microbial activities were subsequently fractionated using 5 different solvents, and further screened for anti-microbial activities. The inhibitory effects of ethyl acetate (EtOAc) extracts on microbial growth were greater compared to any other solvent extracts. In order to investigate the inhibitory effect of Korean medicinal herbs with high anti-microbial activities on microbial proliferation, the MeOH extracts at concentrations of 0, 100, 300 and 500 ppm were added to the media. No addition of extracts caused rapid growth of microbes after 12 hours incubation. As the concentration of extracts from Rhus javanica and Caesalpinia sappan increased, the growth-inhibiting effect on gram-positive bacteria including S. aureus, S. epidermidis, and L. monocytogenes was prominent. Rhus javanica extracts exhibited growth-inhibiting activity for gram-negative bacteria including Sal. Pullorum and Sal. Choleraesuis. The low concentration of extracts from Rhus javanica and Caesalpinia sappan exhibited the growth of Bor. bronchiseptica and E. coli serotype $O_8$. However, the higher concentration of extracts from Rhus javanica and Caesalpinia sappan exhibited a strong inhibitory effect on microbial proliferation.

• Journal of Nutrition and Health
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• v.10 no.4
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• pp.68-83
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• 1977

영양실태조사 및 사람을 대상으로 하는 많은 영양적 연구에서 요중(尿中) 여러 성분(成分)들의 배설량을 측정하기 위해 만 하루의 소변을 완전히 채취하기는 매우 어려우므로 임의시간(任意時間)의 소변을 채취하여 사용한다. 이 경우엔 흔히 요성분(尿成分)의 농도는 요중(尿中) 크레아티닌을 양(量)을 기준으로 하여 표시되는데, 크레아티닌은 요중(尿中) 일일(一日) 배설량이 개인에 따라 알정하고 요양(尿量)에는 상관없이 비교적 일정한 속도로 배설 된다고 간주되기 때문이다. 그러나 비교적 높은 발생율을 갖는 세균재(細菌在) 요도염(尿道炎)에서는 감염균(感染菌)이 크레아티닌을 파괴할 가능성이 있고 따라서 이 경우의 요중(尿中) 크레아티닌의 여러 용도(用途)는 비합리적으로 될 수 있다. 본 연구에서는 이 가설을 규명하려고 한다. 첫 실험에서는 감염균(感染菌)이 요소(尿素)를 암모니아로 파괴함으로써 형성되는 요(尿)의 알칼리성에 대한 크레아티닌의 안정성(安定性)을 알아 보았다. 건강인(健康人)의 요중(尿中) 크레아티닌과 완충액에 용해시킨 순수 크레아티닌을 pH $4.5{\sim}9.0$으로 조정하여 $37^{\circ}C$에서 6일간 배양시켰다. 잔존한 크레아티닌을 측량한 결과, 크레아티닌은 완충용액이나 요(尿)에서서 모두 산성 pH에서 보다 알칼리 pH에서 더욱 안정(安定)함을 보여주었다. 1일간 배양 후엔 거의 변화(變化)가 없었고 6일 후에나 $4.2{\sim}8.0%$의 감소율을 나타냈을 뿐이다. 두번째 실험에서는 감염균이 크레아티닌을 성장(成長)을 위한 질소급원으로 사용하는지를 결정하기 위해 세균성(細菌性) 요도염(尿道炎)에서 자주 발견되는 13종류(種類)의 박테리아를 건강인(健康人)의 요(尿)와 크레아티닌을 질소급원으로 하는 합성배지(合成培地)에 $37^{\circ}C$로 배양하였다. 대부분의 박테리아는 크레아티닌함양(含量)을 감소시키지 않았다. 그러나 Pseudomonas aeruginosa와 Klebsiella pneumoniae는 합성배지중(合成培地中)의 크레아티닌을 상당량 파괴시켰고, 그 파괴율은 그들 성장율과 평행하였다. 배양 6일후에는 크레아티닌이 Pseudomonas aeruginosa에 의해 처음 양(量)(500mg/100m1) 의 12.8%가, Kleobsiella pneumoniae에 의해서는 11.8%가 감소되었다. 감소율은 크레아티닌의 처음 농도가 낮을수록 커져서 50mg/100ml 일 때는 각각 21.1%와 28.2%이었다. 더욱이 Klebsiella pneumoniae는 황산암모늄과 요소(尿素)같은 다른 질소급원이 크레아티닌과 공존(共存)할 때에도 크레아티닌을 어느 정도 파괴함을 보여 주었다. 결론으로, 세균성(細菌性) 요도염(尿道炎)환자의 요(尿)의 알칼리성은 요중(尿中) 크레아티닌양(量)에 중요한 영항을 주지 못한다. 그러나 본(本) 연구(硏究)에서 사용된 Klebsiella pneumoniae와 가능하게는 Pseudomonas aeruginosa 같은 몇 감염균(感染菌)은 크레아티닌을 그들 성장(成長)의 질소급원으로 사용하여 요중(尿中) 크레아티닌양(量)을 저하시킬지도 모른다. 특히 요(尿)에 요소(尿素), 요산(尿酸)같은 다른 질소급원이 크레아티닌에 비해 비교적 낮은 비율로 존재할 때에, 예(例)를 들면 저(低)단백식사(食事)인 경우, 감염균에 의한 크레아티닌의 파괴율이 더 클 것으로 기대된다.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.6
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• pp.798-802
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• 1999

This study was performed to compare the effect of enrichement of rotifer and Artemia fed marine bacteria (Erythrobacter sp. S$\pi$-1) with those fed the different diets-(Super Selco, $\omega$-yeast and marine Chlorella) on the slime flounder larvae, Microstomus achne. Because the ratio of docosahexaenoic acid (DHA) to fatty acids in rotifer (dry weight $\%$) fed on Super Selco and ESP-SR including Erythrobacter sp. S$\pi$-1 was higher than that in rotifer fed marine Chlorella, the growth of the slime larvae fed the former showed better than the latter. And the ratio of DHA and highly unsaturated fatty acid (n-3 HUFA) to fatty acids in Artemia (dry weight $\%$) enriched by ESP-A including Erythrobacter sp. S$\pi$-1 were also higher than those in Artemia enriched by others or Artemia without enrichment. Larvae fed on Artemia enriched by ESP-A showed better growth and survival rate than those fed on Artemia enriched by others or Artemia without enrichment. With regard to dietary value of Erythrobacter sp. S$\pi$-1, its use could improve the quality of the live foods for the slime flounder larvae.