• Title/Summary/Keyword: selective medium

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Development of a Selective Medium for Xanthomonas campestris pv. translucens (맥류 세균성줄무늬병균의 선택배양기 개발)

  • ;David C. Sands
    • Korean Journal Plant Pathology
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    • v.12 no.4
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    • pp.381-388
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    • 1996
  • 맥류세균성 줄무늬병균의 선택배양기(KM-1)를 개발하여 이병식물체 및 토양으로부터 Xanthomonas campestris pv. translucens를 선택적으로 분리할 수 있는 효율성을 검토하였다. KM-1배양기의 구성성분은 증류수 1 L당 lactose 10 g, D(+)trehalose 4.0 g, thiobarbituric acid 0.2 g, K\ulcornerHPO\ulcorner 및 KH\ulcornerPO\ulcorner 각각 0.8 g, yeast extract 30 mg, NH\ulcornerCl 1 g, cycloheximide 100 mg, tobramycin 8.0 mg, ampicillin 1.0 mg 및 Bacto agar 15 g이며 1 N NaOH로 pH 6.6으로 조절하였다. X. c. t.의 균주별 KM-1의 배양효율은 비선택성 농후배지인 Wilbrinks agar에 비하여 1.30정도였으며, 기타 토양전염성식물병원세균 Agrobacterium tumefaciens, Agrobacterium rhizogenes, Erwinia carotovora var. atroseptica, Erwinia carotovora var. carotovora, Corynebacterium insidiosum, 및 기타 토양생존 부생세균 Bacillus cereus, Pseudomonas aeruginosa, Pseudomonas fluorescens, and Pseudomonas putida 등의 생장을 완벽하게 억제하였다. KM-1의 저장기간(shelf-life)도 5$^{\circ}C$에서 2개월 동안 선택성을 유지하였다. 따라서 본 병원균의 전염원의 생존 등 발생생태연구에 활용될 수 있는 가치가 충분히 인정되었다.

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Selective Homologous Expression of Recombinant Manganese Peroxidase Isozyme of Salt-Tolerant White-Rot Fungus Phlebia sp. MG-60, and Its Salt-Tolerance and Thermostability

  • Kamei, Ichiro;Tomitaka, Nana;Motoda, Taichi;Yamasaki, Yumi
    • Journal of Microbiology and Biotechnology
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    • v.32 no.2
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    • pp.248-255
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    • 2022
  • Phlebia sp. MG-60 is the salt-tolerant, white-rot fungus which was isolated from a mangrove forest. This fungus expresses three kinds of manganese peroxidase (MGMnP) isozymes, MGMnP1, MGMnP2 and MGMnP3 in low nitrogen medium (LNM) or LNM containing NaCl. To date, there have been no reports on the biochemical salt-tolerance of these MnP isozymes due to the difficulty of purification. In present study, we established forced expression transformants of these three types of MnP isozymes. In addition, the fact that this fungus hardly produces native MnP in a high-nitrogen medium (HNM) was used to perform isozyme-selective expression and simple purification in HNM. The resulting MGMnPs showed high tolerance for NaCl compared with the MnP of Phanerochaete chrysosporium. It was worth noting that high concentration of NaCl (over 200 mM to 1200 mM) can enhance the activity of MGMnP1. Additionally, MGMnP1 showed relatively high thermo tolerance compared with other isozymes. MGMnPs may have evolved to adapt to chloride-rich environments, mangrove forest.

Bacterial Diversity in the Initial Fermentation Stage of Korean and Chinese Kimchi (발효 초기 한국산 및 중국산 김치의 Bacteria 다양성 평가)

  • Lee, Myeong-Jae;Cho, Kyeung-Hee;Han, Eung-Soo;Lee, Jong-Hoon
    • Microbiology and Biotechnology Letters
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    • v.38 no.2
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    • pp.207-215
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    • 2010
  • The purpose of this research is to draw the bacterial community difference between Korean and Chinese kimchi for future use in the confirmation of kimchi origin. Initial fermentation stage kimchi samples (above pH 5) were used for the analysis of bacterial diversity. From 26 Korean kimchi samples, 1,017 strains in the 45 genera and from 22 Chinese kimchi samples, 842 strains in the 54 genera were isolated with use of marine medium, nutrient medium, succinate minimal medium (SMM), leuconostocs selective medium (LUSM) agars. In the order of isolated numbers, Bacillus, Weissella, Leuconostoc, Pseudomonas, and Lactobacillus genera and Bacillus, Weissella, Lactobacillus, Pseudomonas, Serratia, and Enterobacter genera were predominated in Korean and Chines kimchi, respectively. Among the isolated lactic acid bacteria, Weissella spp. were isolated most dominantly owing to the biased growth of Weissella spp. on LUSM agar. Species in the genera Leuconostoc and Lactobacillus were the next frequently isolated LAB from Korean and Chinese kimchi, respectively. Weissella confusa was isolated only from Korean kimchi and W. soli and Serratia proteamculans were isolated only from Chinese kimchi. They have a possibility to be used as target bacteria to differentiate Korean kimchi from Chinese kimchi.

Isolation and Identification of Pathogenic Microorganisms from Soybean Sprouts

  • Kim, Hye-Jung;Koo, Kyoung-Mo;Kim, Gi-Nahm;Lee, Dong-Sun;Paik, Hyun-Dong
    • Preventive Nutrition and Food Science
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    • v.7 no.3
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    • pp.305-309
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    • 2002
  • Raw soybean sprouts were tested for contamination with the following bacteria which have potential for pathogenesis or food spoilage : Salmonella spp., Escherichia coli O157:H7, Yersinia enterocolitica, Vibrio parahae-molyticus, Aeromonas hydrophila, Plesidomonas shigeloides, Pseudomonas aeruginosa, Staphylococcus aureus, Lis-teria monocytogenes, Bacillus cereus, Clostridium perfringens, Campylobacter jejuni, Erwinia spp., and Fusarium spp. Three of the above strains were isolated from the sprouts, and identified by morphological and biochemical methods including an API kit and ATB automated identification system. The isolate cultured in Cereus selective agar, a selective medium, was a Gram-positive, rod shaped, anaerobic spore former. The biochemical and culture tests revealed the following characteristics: catalase-positive, no growth on Simmon's citrate, NO₂ production and requirement of arginine for growth; the ATB automated identification system gave 99.8 % agreement for the identification of Bacillus cereus to the species level. The isolate cultured in Macconkey agar selective medium was Gram-negative, rod shaped and a gas former; the ATB-system gave 99.9% agreement for the identification of Aeromonas hydrophila to the species level. The isolate found in Pseudomonas isolation agar was Gram-negative, rod shaped, cytochrome oxidase-positive, a reducer of nitrates to nitrogen, and pyocyanin producer; the ATB-system gave 99.9 % agreement for the identification of Pseudomonas aeruginosa to the species level. These results indicate that the three bacteria species present in the soybean sprouts were Bacillus cereus, Aero-monas hydrophila, and Pseudomonas aeruginosa. Salmonella spp., Escherichia coli O157:H7, and Yersinia enter-ocolitica, which are associated with serious disease in humans, were not isolated from soybean sprouts examined in this study.

Studies on the Selective Media for Bifidobacterium infantis Maeil-K9 Using Various Carbon Sources and Antibiotics (Bifidobacterium infantis Maeil-K9 균주의 당 발효 특성 및 항생제 내성을 이용한 선택배지 개발연구)

  • 정병문;김응률;정후길;전호남
    • Korean Journal of Microbiology
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    • v.40 no.1
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    • pp.37-42
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    • 2004
  • To differentiate commercial bifidobacteia for Bifidobacterium lactis Bb-12, Bif. longum Bb-536 and Bif. infantis Maeil-K9, we studied the various carbon source, the nitrogen sources and antibiotics. Amygdalin and fructose were good candidates for carbon sources, and tryptone was suitable for nitrogen sources to design a new selective media for three commercial bifidobacteria. In the case of the amygdalin-containing medium as carbon sources, Bif. lactis Bb-12 and Bif. infantis Maeil-K9 showed good growth, and in fructose-containing medium, Bif. longum Bb-536 showed good growth. In antibiotics resistance study, the addition of 1 mg/L doxycyclin was very effective for differentiation of each bifidobacteria. Doxycyclin did not affect the growth of Bif. lactis Bb-12 and Bif. infantis Maeil-K9, but Bif. longum Bb-536 was completely inhibited by doxycyclin. Finally to confirm the selection capability of newly designed selective media, temperature-shocked bifidobacteria were cultured on them. As the results, fructose or doxycyclin containing medium showed for high growth for temperature-shocked bifidobacteria, but amygdalin containing medium showed low growth of temperature-shocked bifidobacteria.

Linear and Hyperbranched Polymers via Electrophilic Substitution Reaction in Polyphosphoric $Acid/P_{2}O_{5}$

  • Choi, Ja-Young;Jeon, In-Yeop;Tan, Loon-Seng;Baek, Jong-Beom
    • Proceedings of the Polymer Society of Korea Conference
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    • 2006.10a
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    • pp.195-195
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    • 2006
  • A superior electrophilic substitution reaction medium that is non-toxic, relatively less corrosive, and non-volatile electrophilic substitution reaction to afford high molecular weight linear and hyperbranched polyetherketones (PEK' s) was developed. The system has very strong driving force to give extra ordinary high molecular weight linear and hyperbranched PEK' s. The reaction medium was further extended to prepare various types of copolymers and covalently grafted polymers onto carbon nanotube (CNT) or carbon nanofiber (CNF). By using characteristic hydrophilic nature of the reaction medium, hyperbranched PEK' s could be synthesized from commercially available $A_3\;+\;B_2$ monomers without network formation via selective solubility of the monomers.

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Application of Selective Construction Management Services to Private Small-Medium Construction Projects (${\cdot}$ 소규모 건축공사의 선택적 건설사업관리 적용 방안)

  • Kim, Seong-Hwan;Mun, Kyung-Jick;Woo, Yu-Mi;Koo, Kyo-Jin;Hyun, Chang-Taek
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • 2006.11a
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    • pp.305-309
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    • 2006
  • Construction management system has been needed to be anchored and revitalize in these days, since it was entered into a domestic market. We could consider application of CM services as a challenge of construction project system and a way to get to an advanced nation in construction field. Application of CM services could be possible in public projects by a regime. However, in case of private construction projects, it is hard to apply it without understanding of substantial necessity and propriety. so in this study, we find a application method of CM services to private small-midium construction projects, and make CM services item table of CM services for revitalization by examining the cases that applied to in private small-medium construction projects.

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Transceiver for Human Body Communication Using Frequency Selective Digital Transmission

  • Hyoung, Chang-Hee;Kang, Sung-Weon;Park, Seong-Ook;Kim, Youn-Tae
    • ETRI Journal
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    • v.34 no.2
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    • pp.216-225
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    • 2012
  • This paper presents a transceiver module for human body communications whereby a spread signal with a group of 64 Walsh codes is directly transferred through a human body at a chip rate of 32 Mcps. Frequency selective digital transmission moves the signal spectrum over 5 MHz without continuous frequency modulation and increases the immunity to induced interference by the processing gain. A simple receiver structure with no additional analog circuitry for the transmitter has been developed and has a sensitivity of 250 ${\mu}V_{pp}$. The high sensitivity of the receiver makes it possible to communicate between mobile devices using a human body as the transmission medium. It enables half-duplex communication of 2 Mbps within an operating range of up to 170 cm between the ultra-mobile PCs held between fingertips of each hand with a packet error rate of lower than $10^{-6}$. The transceiver module consumes 59 mA with a 3.3 V power supply.

Usefulness of microwave to melt rehydrated media and to remove oxygen from anaerobic tube media (Microwave를 이용한 배지 융해와 공기 제거)

  • 정윤섭;이귀녕;이삼열
    • Korean Journal of Microbiology
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    • v.18 no.3
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    • pp.148-152
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    • 1980
  • The microwave of 2450 MHz, generated by a household cooking oven, was evaluated for its applicability to melt various rehydrated media and to remove dissolved oxygen from tubed media for anaerobic culture. The effect on the sterilization of E. coli in selective media was also evaluated. The following results were obtained. 10 The microwave oven was useful in saving time for melting media and in eliminating heat and combustion gas from the laboratory, which were inevitable by-products in the conventional flame method. 2) Dissolved oxygen could be removed without boiling over by exposing the tubes of anaerobic culture medium after putting them in a wire basket in a beaker with water. 30 The count of E. coli during the melting of MacConkey and EMB agar were similar to those treated with open flame. The microwave treatment was not considered a possible mean to replace autoclaving even in these selective media.

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PCISS Scheme for Minimize Prove Delay in Wireless Mesh Networks (무선 메쉬 네트워크 환경에서 프로브 지연을 최소화한 PCISS 기법)

  • Cho, Young-Bok;Lee, Sang-Ho
    • Journal of Convergence Society for SMB
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    • v.2 no.1
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    • pp.25-31
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    • 2012
  • Recently Wireless Communication technologies are widely used in Small And Medium Business fields. Wireless mesh networks have been studied as the next generation technology to solve problem of conventional wireless networks. Wireless mesh network uses a 802.11 when make up of network. mesh clients occurs Hard handover moving between ones. This increases the handover latency of the network mobility is a very great issues. Consequently, this paper propose a channel information previously methods to reduce the handover latency selective channels. Proposed scheme accounts for more than 90% of the probe delay to minimize the client had to move the mesh based on the old channel to retrieve information. Through simulation, the proposed scheme had shorter handover delay time than transitional full scan and selective scan. Through results of evaluation, the suggest PCISS scheme more fast 6.5% than transitional scheme.

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