• Title, Summary, Keyword: Bacteria

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Inhibition of Clinical Nosocomial Bacteria by Chlorine Dioxide

  • Jung, Suk-Yul
    • Biomedical Science Letters
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    • v.25 no.4
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    • pp.431-435
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    • 2019
  • Chlorine dioxide is an effective chemical to inhibit the growth of bacteria and viruses or to disinfect infected areas. In this study, the effects of chlorine dioxide on several bacteria in hospitals were analyzed. Alloiococcus otitis, Kocuria rosea, Leuconostoc mesenteroides spp. and Staphylococcus lentus as gram-positive bacteria and Acinetobacter lwoffii, Aeromonas salmonicida, Brucella melitensis, Oligella ureolytica as gram-negative bacteria were done for the inhibitory analysis. The growth and morphology of the bacteria were analyzed by placing a plastic stick which was called "FarmeTok (medistick/Puristic)" provided by Purgofarm, co, Ltd. to release ClO2 (13 ppmv/hr) next to the plate where the bacteria were incubated for 24 hours. Less than 10 bacterial colonies were evaluated as having 99% inhibitory effect. The initial bacterial culture concentration of 0.5 McFaland turbidity was good for analyzing the chlorine dioxide inhibitory effect. All bacteria could be easily counted post 24 hr co-incubation with ClO2, but A. otitis and A. lwoffii without ClO2 gas were not countable due to very dispersed colony types which were not affected for result analysis. As shown in this study, the FarmeTok plastic stick, which discharges chlorine dioxide at 13 ppmv / hour, was evaluated to be sufficient to suppress the above bacteria in the hospital. Bacteria existing in the clinic such as this hospital will be used as a data to inhibit the growth of bacteria by using ClO2, and molecular biology analysis using the gene of bacteria will be possible in the future rather than inhibiting the growth of bacteria itself.

Interactions between marine bacteria and red tide organisms in Korean waters

  • Seong, Kyeong Ah;Jeong, Hae Jin
    • ALGAE
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    • v.28 no.4
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    • pp.297-305
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    • 2013
  • There is increasing interest in the relationships between marine bacteria and red tide organisms. Some bacteria are known to kill red tide organisms, and may be responsible for accelerating the termination of red tides. Thus, certain algicidal bacteria have been proposed for the control of red tides. Meanwhile, many red tide organisms are known to feed on marine bacteria. The roles of marine bacteria and red tide organisms are therefore reversible. In Korean waters, the killing of red tide organisms by algicidal bacteria, and also the feeding of red tide organisms on marine bacteria have been extensively investigated. The findings of such studies may influence the conventional view of red tide dynamics, and also planktonic food webs. Here, we review the species and concentrations of algicidal bacteria that kill red tide organisms in Korean waters, as well as the ingestion rate and grazing impact of red tide organisms on marine bacteria. Furthermore, we offer an insight into the ecological roles of these 2 components in marine planktonic food webs.

Lactic held Bacteria for the Preservation of Fruit and Vegetables (과실 및 채소류의 저장에 있어서 Lactic Acid Bacteria의 이용)

  • 김건희;배은경
    • Korean Journal of Food Preservation
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    • v.6 no.2
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    • pp.245-254
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    • 1999
  • Traditionally, lactic acid bacteria(LAB) is microorganism that has been used for food fermentation. Bacteriocinogenic culture and by-products of lactic acid bacteria have the antimicrobial effect. The antimicrobial effect of lactic acid bacteria enable to extend the shelf life of many foods through fermentation processes. Therefore, a lot of investigation of antimicrobial compounds from LAB have been studied on the effect of foods preservation of fish, meat, dairy product, refreserated nonfermentive food and so on. However a little research on the effects of LAB in fruit and vegetables preservation has been reported. In this study, effectiveness of LAB as a quality preservative in fruit and vegetables storage were reviewed.

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A Novel Optimization Algorithm Inspired by Bacteria Behavior Patterns

  • Jung, Sung-Hoon;Kim, Tae-Geon
    • Journal of Korean Institute of Intelligent Systems
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    • v.18 no.3
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    • pp.392-400
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    • 2008
  • This paper proposes a novel optimization algorithm inspired by bacteria behavior patterns for foraging. Most bacteria can trace attractant chemical molecules for foraging. This tracing capability of bacteria called chemotaxis might be optimized for foraging because it has been evolved for few millenniums. From this observation, we developed a new optimization algorithm based on the chemotaxis of bacteria in this paper. We first define behavior and decision rules based on the behavior patterns of bacteria and then devise an optimization algorithm with these behavior and decision rules. Generally bacteria have a quorum sensing mechanism that makes it possible to effectively forage, but we leave its implementation as a further work for simplicity. Thereby, we call our algorithm a simple bacteria cooperative optimization (BCO) algorithm. Our simple BCO is tested with four function optimization problems on various' parameters of the algorithm. It was found from experiments that the simple BCO can be a good framework for optimization.

A Test of Two Models for the Bacteria Flux across the Sediment/Water Interface in an Effluent-dominated Stream (하수처리 방류 소하천내 퇴적물로부터의 박테리아 유출 플럭스모델 비교)

  • Ahn, Jong-Ho
    • Journal of Korean Society of Water and Wastewater
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    • v.24 no.2
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    • pp.165-172
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    • 2010
  • Treated sewage could enable growth by providing key nutrients or seeding the sediments with enterococci strains that can grow in the environment. This study is to test the hypothesis that the flux of bacteria into the water column is rate-limited by the transfer of bacteria across the sediment/water interface. Two conceptual models are derived for the transfer of bacteria to the water column from the sediment/water interface: convective diffusion of isolated bacteria and resuspension of particle-associated bacteria. The model predictions are directly tested together with field measurements of bacteria and sediment in an effluent-dominated stream where high concentrations of enterococci in this stream originate primarily from growth of the bacteria in stream sediments. The results reveal that high concentrations of enterococci in this stream are transported primarily by resuspension of particle-associated bacteria accumulated at the sediment/water interface, either in the form of bacterial aggregates or in the form of inorganic particles.

Study on Antibiotic Resistant Bacteria in Surface Water Receiving Pharmaceutical Complex Effluent (제약공단 방류수 유입 하천에서의 항생제 내성 bacteria에 관한 연구)

  • Kim, Young Jin;Kim, Young Gyu
    • Journal of Environmental Health Sciences
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    • v.42 no.6
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    • pp.409-418
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    • 2016
  • Objectives: The purpose of this study was to characterize penicillin G resistant bacteria in surface water from pharmaceutical complex effluent. Methods: Surface water was sampled from pharmaceutical complex effluent in Gyeonggi-do Province, Korea in March 2015. Water samples were plated in triplicate on tryptic soy agar plates with 32 mg/L of penicillin G. Penicillin G resistant bacteria were selected from the effluent and subjected to 16S rRNA analysis for the penicillin G resistant species determination. Identified resistant strains were tested for resistance to various antibiotics. Results: Penicillin G resistant bacteria were present at 8.0% in terms of culturable heterotrophic bacteria. Identified penicillin G resistant bacteria exhibited resistance to more than nine of the antibiotics studied. These resistant bacteria are gram negative and are closely related to pathogenic species. Conclusion: Multi-antibiotic resistant bacteria in the surface water of pharmaceutical complex effluent suggest the need for disinfection and advanced oxidation processed for pharmaceutical effluent.

Changes of Index Microorganisms and Lactic Acid Bacteria of Korean Fermented Vegetables (Kimchi) during the Ripening and Fermentation-Part 1 (김치의 숙성 및 발효중 오염지표미생물과 유산균의 변화-제1보)

  • Kim, Jong-Gyu;Yoon, Joon-Sik
    • Journal of Environmental Health Sciences
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    • v.31 no.1
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    • pp.79-85
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    • 2005
  • This study was undertaken to investigate the changes of index microorganisms and lactic acid bacteria of traditional Korean fermented vegetables (kimchi) during the ripening and fermentation period. A type of kimchi, baechoo-kimchi, was prepared and stored at $10^{\circ}C$ for 8 days. The numbers of the total aerobic bacteria, psychrotrophilic bacteria, coliform bacteria, and Escherichia coli in the kimchi and also in raw materials of the kimchi (Chinese cabbage, green onion, ginger, garlic, and red pepper) were counted using appropriate media. The highest number of aerobic bacteria was detected from ginger, then red pepper, then garlic, then Chinese cabbage, and lowest number from green onion. The highest number of psychrotrophilic bacteria was detected from red pepper, then Chinese cabbage, then garlic, then ginger, and the lowest number from green onion. Coliforms and E. coli were not detected from all of the raw materials of kimchi. Total aerobic bacteria and lactic acid bacteria of the kimchi showed gradually increasing during ripening and fermentation. The number of psychrotrophilic bacteria showed a similar level in the kimchi. Coliform bacteria were detected at the 3rd, 4th, and 5th day of the kimchi fermentation period, although they were not detected from the raw materials of the kimchi. However, the bacteria were not detected in the kimchi after 6 days. E. coli was not detected in all kimchi samples. The pH value of the kimchi gradually decreased, and acidity increased over fermentation period. This study indicates that there was contamination of coliform bacteria during the process of kimchi preparation, and lactic acid bacteria proliferated in the kimchi during fermentation inhibited the growth of coliforms. More research is needed to evaluate the inhibitory effects of each raw materials of kimchi.

Hygienic Superiority of Kimchi (김치의 위생학적 우수성)

  • Kim, Yong-Suk;Shin, Dong-Hwa
    • Journal of Food Hygiene and Safety
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    • v.23 no.2
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    • pp.91-97
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    • 2008
  • Kimchi is a representative traditional food in Korea and a type of vegetable product that is the unique complex lactic acid fermentation in the world. It can be considered as a unique fermented food generated by various flavors, which are not included in raw materials, that can be generated by mixing and fermenting various spices and seasonings, such as red pepper powder, garlic, ginger, and salted fish, added to Chinese cabbages. Functionalities in Kimchi have been approved through several studies and the probiotic function that is mainly based on lactic acid bacteria including their physical functions in its contents has also verified. Studies on the verification of the safety of Kimchi including its physiological functions have been conducted. In particular, the function of lactic acid bacteria, which is a caused of the fermentation of Kimchi. Although the lactic acid bacteria contributed to the fermentation of Kimchi is generated from raw and sub-materials, the lactic acid bacteria attached on Chinese cabbages has a major role in the process in which the fermentation temperature and dominant bacteria are also related to the process. The salt used in a salt pickling process inhibits the growth of the putrefactive and food poisoning bacteria included in the fermentation process of Kimchi and of other bacteria except for such lactic acid bacteria due to the lactic acid and several antimicrobial substances generated in the fermentation process, such as bacteriocin and hydrogen peroxide. In addition, the carbon dioxide gas caused by heterolactic acid bacteria contributes to the inhibition of aerobic bacteria. Furthermore, special ingredients included in sub-materials, such as garlic, ginger, and red pepper powder, contribute to the inhibition of putrefactive and food poisoning bacteria. The induction of the change in the intestinal bacteria as taking Kimchi have already verified. In conclusion, Kimchi has been approved as a safety food due to the fact that the inhibition of food poisoning bacteria occurs in the fermentation process of Kimchi and the extinction of such bacteria.

Factors Influencing Airborne Concentration of Fungi, Bacteria and Gram Negative Bacteria in Kindergarten Classroom (유치원 교실에서 공기 중 박테리아와 곰팡이 발생에 영향을 미치는 요인)

  • Park Donguk;Jo Kyunga;Yoon Chungsik;Han Inyoung;Park Dooyong
    • Journal of Environmental Health Sciences
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    • v.30 no.5
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    • pp.440-448
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    • 2004
  • Airborne bacteria, gram negative bacteria (GNB) and fungi were measured in 70 class of 17 kindergartens. The objective of this study is to identify the factors influencing airborne concentrations of bacteria, GNB and fungi using multiple regression analysis. The average concentrations of bacteria and fungi exceeded $1,000\;CFU/m^3$. The average of GNB was $3.7{\times}10^2\;CFU/m^3$. This results indicated that air of kindergartens was contaminated with microbes such as bacteria and fungi. ANOVA test found that the concentrations of bacteria, GNB and fungi were significantly different by the characteristics of weather (rain, after rain, sunny) sampling date (July, August, September and October), the location of sampling site (ground level and basement) and the location of toilet (inside class, nearby class and away class). Multiple regression tests concluded that sampling date, the scale of city where kindergartens are located, the location of sampling site and ventilation efficiency can significantly affect the airborne concentration of bacteria, GNB and fungi. Most of these factors could be related moisture. Environmental factors that can cause the increment of moisture should be controlled in order to reduce airborne concentration of bacteria, GNB and fungi. Legal actions concerning prohibition on the presence of toilet inside class and ventilation criteria should be taken.

Verification of Calcium Carbonate by Cementation of Silt and Sand Using Bacteria (Bacteria를 이용한 실트와 모래의 고결화에 따른 탄산칼슘 확인)

  • Park, Kyung-Ho;Kim, Dae-Hyeon
    • Journal of the Korean Geotechnical Society
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    • v.28 no.6
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    • pp.53-61
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    • 2012
  • The purpose of this study is to understand the mechanism of cementation of soil induced by bacteria. In order to understand the mechanism of cementation of soft soils treated with bacteria, six types of specimens(Not treated, Normal concentration bacteria treatment, High concentration bacteria treatment, Supernatant high concentration bacteria treatment, Double high concentration bacteria treatment, and 25% Specimen high concentration bacteria treatment) were made. Scanning Electron Microscope (SEM), EDX and X-ray diffraction (XRD) analyses were performed on the soft silt and loose sand specimens. Compared with the normal bacteria concentration treated specimen, a clearer cementation between particles was observed in the 25% specimen high bacteria concentration treated specimen. On the basis of the preliminary results, it appears that microbial cementation can occur in the soft soil.