• 제목/요약/키워드: lethal temperature

검색결과 111건 처리시간 0.033초

연안 해수에서 분리된 Vibrio mimicus K-1의 특성 (Characteristics of Vibrio mimicus K-1 Isolated from Coastal Sea Water)

  • 고병호;이원재;이명숙
    • 한국수산과학회지
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    • 제27권3호
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    • pp.292-298
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    • 1994
  • 식중독 원인균으로 알려진 Vibrio mimicus(V. mimicus)의 분포 상태와 이의 생리적 특성을 조사하기 위하여 1993년 1월부터 9월까지 민락동과 광안리 해수욕장 부근의 해수를 채취하여 V. mimicus의 월별 분포 상태를 실험하였으며, 여기서 분리된 균주 중에서 항생제 내성이 강한 균으로 분리, 동정된 V. mimicus K-1의 생리적 성질과 배양 특성을 조사하였다. 수온이 $16.3^{\circ}C$인 4월부터 검출되기 시작하여 8월까지 검출되었으나, 수온이 $15^{\circ}C$ 이하인 겨울철(1, 2, 3월)에는 전혀 검출이 되지 않았다. 분포 정도는 최소 0.4(MPN/100ml)에서 최고 70((MPN/100ml)으로 지역에 따라 차이가 있었다. V. mimicus K-1은 $37^{\circ}C$, pH 7.5, 그리고 염도 $0.5\%$에서 각각 최대의 증식율을 보였다. 그리고 항생제 (colistin, erythromycin, bacitracin, tetracycline, penicillin)에 대해서 내성을 나타내었다. 자외선(30W, 50m)에 대해서는 상당히 내성이 약했으며, 70초간 조사 후에는 검출이 되지 않았다. 열에 의한 치사율은 $50^{\circ}C$에서 5.7분, $60^{\circ}C$에서 2.1분, 그리고 $70^{\circ}C$에서는 0.7분 만에 최초균수의 $90\%$이상이 사멸하였다.

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태양열 소독시 유기물과 석회질소 병행 처리에 의한 딸기 시들음병균 방제 (Control of Fusarium Wilt of the Strawberry Caused by Fusarium oxysporum f. sp. fragariae of Solarization with Compost and Calcium Cyanamide Application)

  • 남명현;김현숙;김홍기
    • 식물병연구
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    • 제17권1호
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    • pp.32-37
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    • 2011
  • 유기물, 석회질소, 요소 병행처리가 딸기 시들음병의 친환경적 방제인 태양열소독의 효과 증진여부를 밝히고자 논산딸기시험장의 비닐하우스에서 2006년과 2008년에 분석하였다. 딸기에서 분리한 Fusarium oxysporum f. sp. fragariae 7개 균주의 100% 치사시간은 $45^{\circ}C$에서 6.6일, $50^{\circ}C$에서는 5.1일이 소요되었고 100% 치사온도는 $46.7{\pm}0.1^{\circ}C$로 나타났다. 태양열 소독에 의해 유기물 처리구는 처리전보다 토양내 유기물 함량이 증가하였고, 석회질소 처리구는 산도, 유기물, 칼슘 함량이 증가하였으나 요소처리구는 차이가 없었다. 태양열 소독시 지온은 처리간에 차이를 나타냈으며 7월 30일부터 8월 10일까지가 가장 높았고($48.4\sim54.8^{\circ}C$) 유기물+석회질소 처리구가 다른 처리구보다 $3\sim4^{\circ}C$ 높게 유지되었다. 또한 토양내 시들음병균은 각 처리구 모두에서 사멸되었다. 시들음병 이병주율은 무처리는 2006년 20%, 2008년 13.3%의 발병율을 나타낸 반면 태양열 소독 처리구 모두에서는 시들음병 발생이 없었으며 처리간 유의성이 있었다. 따라서 딸기 시들음병 방제를 위한 유기물+석회질소를 병행한 태양열 소독 방법은 기존의 태양열소독방법을 보완하여 처리기간을 줄이면서도 효과적인 방법이 될 것이다.

Analysis of Thermotolerance in Hot Pepper Using the Antiserum Against Carrot HSP17

  • Hwang, Eun-Young;Hwang, Cheol-Ho;Yoo, Il-Woong
    • Journal of Plant Biotechnology
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    • 제3권1호
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    • pp.7-12
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    • 2001
  • An antiserum against the carrot HSP17 (17 KDa heat shock protein) was raised using the HSP17 purified after being expressed in a recombinant E.coli in order to develop an assay system for thermotolerance in crops. The DCHsp17.7 including the coding sequence corresponding to a carrot HSP17 protein was recombined within pET-32(b) vector and achieved a maximum expression in 4 hours after an induction in E.coli. The purified DCHsp17.7 was used as an antigen to generate the corresponding antibody. The polyclonal antiserum was confirmed for it's specificity only to the low molecular weight (1mw) HSP. Besides, the possibilities to use the antiserum to interact with 1mwHSPs from other plants such as rice, cucumber, tomato, and hot pepper were examined to be plausible. To reveal any specific correlation between the amounts of 1mwHSP expressed upon HS conditions and an acquisition of thermotolerance two different approaches have been applied. first, it has been shown that only the pre-HS conditions inducing the synthesis of HSP17 allowed for the seedlings to achieve an thermotolerance and to survive the following lethal condition. Second, a western analysis using 15 different collected lines of hot peppers was performed to distinguish each other in terms of the amount of 1mwHSP. The results indicated that all 14 hot pepper lines were able to synthesize HSPs in response to an exposure to HS conditions and the amounts of the proteins synthesized at different HS temperatures were variable among the lines. There are several different patterns of 1mwHSP synthesized as a function of temperature increase observed and their correlation to physiological aspects of thermotolerance remains to be analyzed.

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다양한 열처리 조건에서 LMW HSPs의 발현 및 축적량 조사 (Expression and Accumulation of LMW HSPs under Various Heat Shock Conditions)

  • 김기용;장요순;이병현;조진기
    • 한국초지조사료학회지
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    • 제18권4호
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    • pp.303-310
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    • 1998
  • 목초의 내하고성을 증진시킬 목적으로 이용하고자 하는 내열성 유전자 (BcHSP17.6)의 발현양상을 배추에서 조사하였다. BcHSP17.6 단백질을 항원으로 한 항체를 생산하여 항원-항체 반응으로 확인한 결과, 생산된 항체는 항원과 결합하므로서 항체가 정상적으로 생산되었음을 확인하였다. 이 항체를 이용하여 다양한 heat shock (HS) 조건에서 15-~18-kD low molecular weight heat shock proteins (LMW HSPs)가 축적되는지를 조사하였다. 이들 LMW HSPs는 $35^{\circ}C$ 처리에서 나타나기 시작하였으며, $40^{\circ}C$에서 4시간 처리하였을 때 total protein 100 mg당 $1.56{\mu}g$이 축적되어 최대치를 나타내었다. 또한 합성된 이들 LMW HSPs는 HS 처리후 24시간이 경과되어도 거의 변함이 없었으며, $40^{\circ}C$ 보다 높은 온도 조건에서는 축적량이 감소하였다. 이와 같이 일단 합성된 LMW HSPs가 장시간 동안 감소하지 않는다는 사실로부터, 이들 HSPs들이 식물체가 내열성을 가지도록 하는데 관여하며, 더 나아가서 배추가 정상 생육온도보다 더 높은 치사온도에서도 살아남을 수 있도록 하는데 중요한 역할을 하는 것으로 사료된다.

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잘피(Zostera marina)서식지 복원을 위한 최적 이식방법 및 시기 선정에 관한 연구 (Selection of the Optimal Transplanting Method and Time for Restoration of Zostera marina Habitats)

  • 박정임;김영균;박상률;김종협;김영상;김정배;이필용;강창근;이근섭
    • ALGAE
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    • 제20권4호
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    • pp.379-388
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    • 2005
  • Seagrass bed is an important component in coastal and estuarine ecosystems, providing food and shelter to a wide variety of fauna. Recently, seagrass coverage has declined significantly due to anthropogenic influences such as reclamation, dredging, and eutrophication and consequently, necessity of seagrass habitat restoration is rising. Transplantation experiments with Zostera marina using TERFS, staple method, and shell method have been conducted at Dadae Bay, Kosung Bay and Jindong Bay on the south coast of Korea to select an optimal transplanting method for restoration of Z. marina habitat. Three experimental sites located at the vicinity of natural Z. marina beds with an average water depth of about 4m. Z. marina plants, which were collected from donor bed in Koje Bay were also transplanted at 7 different time from October 2003 to July 2004 to find appropriate transplanting time. Density of Z. marina was monitored monthly at both transplanted areas and natural beds. Transplantation using the staple method showed the highest survival rate of transplant. Shell method was also an effective transplanting method at muddy areas in Kosung Bay and Jindong Bay, but not suitable at sandy areas in Dadae Bay. These results suggest that sediment composition of transplanting areas should be considered for the selection of the optimal transplanting method. Z. marina transplanted during fall usually showed the highest survival rate, while most Z. marina plants transplanted in summer died due to high lethal temperature during this period.

Antiplasmodial and Cytotoxic Activities of Toad Venoms from Southern Amazon, Brazil

  • Banfi, Felipe Finger;Guedes, Karla de Sena;Andrighetti, Carla Regina;Aguiar, Ana Carolina;Debiasi, Bryan Wender;Noronha, Janaina da Costa;Rodrigues, Domingos de Jesus;Vieira, Gerardo Magela Junior;Sanchez, Bruno Antonio Marinho
    • Parasites, Hosts and Diseases
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    • 제54권4호
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    • pp.415-421
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    • 2016
  • The drug-resistance of malaria parasites is the main problem in the disease control. The huge Brazilian biodiversity promotes the search for new compounds, where the animal kingdom is proving to be a promising source of bioactive compounds. The main objective of this study was to evaluate the antiplasmodial and cytotoxic activity of the compounds obtained from the toad venoms of Brazilian Amazon. Toad venoms were collected from the secretion of Rhinella marina and Rhaebo guttatus in Mato Grosso State, Brazil. The powder was extracted at room temperature, yielding 2 extracts (RG and RM) and a substance ('1') identified as a bufadienolide, named telocinobufagin. Growth inhibition, intraerythrocytic development, and parasite morphology were evaluated in culture by microscopic observations of Giemsa-stained thin blood films. Cytotoxicity was determined against HepG2 and BGM cells by MTT and neutral red assays. The 2 extracts and the pure substance ('1') tested were active against chloroquine-resistant Plasmodium falciparum strain, demonstrating lower $IC_{50}$ values. In cytotoxic tests, the 2 extracts and substance '1' showed pronounced lethal effects on chloroquine-resistant P. faciparum strain and low cytotoxic effect, highlighting toad parotoid gland secretions as a promising source of novel lead antiplasmodial compounds.

시화호 수질 악화에 따른 시화호와 주변 해역 어류의 종조성 변화 (Changes of Species Composition of Fish in Polluted Lake Shihwa and Adjacent Coastal Area)

  • 이태원;문형태;허성회
    • 한국해양학회지:바다
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    • 제2권2호
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    • pp.110-116
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    • 1997
  • 시화호가 건설 된 후인 1995년 10월에서 1996년 8월 사이 시화호 내부와 외부에서 계절 별로 어류를 채집하여, 출현종의 조성 변화를 분석하고 내부의 수질이 어류에 미치는 영향을 고찰하였다. 호수 외부에서는 청어목 어류 및 참서대와 민태가 우점하여 인접 해역과 유사한 경향을 보였다. 호수 내에서는 가을에 연안성 부어류, 망둑어류 및 민불어류인 붕어가 채집되었으나, 겨울이 지난 후 외해에서 월동하여야 하는 부어류들은 채집되지 않았고, 망둑어류와 붕어도 숫적으로 감소하였다. 봄이 되어 소수 풀망둑을 제외한 어류는 채집되지 않았고, 여름에는 해수와 호수물 교환 과정에서 들어 온 두둘망둑과 구굴무치가 대량 출현하였으나 8월 중순 폐사하였다. 1996년 3월 이후 암모늄 농도는 다른 어류에서 관찰된 반치사농도보다 높았으며, 수온과 pH의 상승으로 암모니아의 어류에 대한 독성이 강하여지고 다른 요인들과 복합적으로 작용하여 어류들이 폐사한 것으로 보인다.

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파밤나방(Spodoptera exigua (Hubner))과 담배거세미나방(Spodoptera litura(Fabricius))에 대한 곤충병원선충(Steinernema carpocapsae Weiser)의 감염력 및 증식력 (Pathogenicity and Multiplication of Entomopathogenic Nematode, Steinernema carpocapsae Weiser, on Been Armyworm, Spodoptera exigua (Hubner) and Tobacco Cutworm, Spodoptera litura(Fabricius))

  • 한상찬;이성섭;김용균
    • 한국응용곤충학회지
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    • 제38권3호
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    • pp.255-260
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    • 1999
  • 곤충병원선충(Steinernema carpocapsae Weiser) 기주 증식을 위해 실내 대량사육이 용이한 파밤나방(spodoptera exigua (Hubner))과 담배거세미나방(Sp. litura (Fabricius))유충에서 병원성과 증식선충수를 조사하였다. 반수치사 병원선충수는 두 기주간 또는 발육시기에 따라 차이가 없었으나 기주내에 증식된 선충수는 기주의 크기에 비례하였다. 온도에 따른 선충의 증식은 온도가 증가함에 따라 기주내 최대 감염태 선충수(담배거세미나방 5령충에서 약 500,000마리, 파밤나방 5령충에서 약 100,000 마리)를 보이는 소요기간이 $25^{\circ}C$에는 접종 후 6일이나 $20^{\circ}C$에서는 12일로 길어졌다.

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Oral and IV Dosages of Doxorubicin-Methotrexate loaded-Nanoparticles Inhibit Progression of Oral Cancer by Down-Regulation of Matrix Methaloproteinase 2 Expression in Vivo

  • Abbasi, Mehran Mesgari;Jahanban-Esfahlan, Rana;Monfaredan, Amir;Seidi, Khaled;Hamishehkar, Hamed;Khiavi, Monir Moradzadeh
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권24호
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    • pp.10705-10711
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    • 2015
  • Oral cancer is one of the most common and lethal cancers in the world. Combination chemotherapy coupled with nanoparticle drug delivery holds substantial promise in cancer therapy. This study aimed to evaluate the efficacy and safety of two dosages of our novel pH and temperature sensitive doxorubicin-methotrexate-loaded nanoparticles (DOX-MTX NPs) with attention to the MMP-2 mRNA profile in a 4-nitroquinoline-1-oxide induced oral squamous cell carcinoma (OSCC) model in the rat. Our results showed that both IV and oral dosages of DOX-MTX NP caused significant decrease in mRNA levels of MMP-2 compared to the untreated group (p<0.003). Surprisingly, MMP-2 mRNA was not affected in DOX treated compared to cancer group (p>0.05). Our results indicated that IV dosage of MTX-DOX is more effective than free DOX (12 fold) in inhibiting the activity of MMP-2 in OSCCs (P<0.001). Furthermore, MMP-2 mRNA expression in the DOX-MTX treated group showed a significant relation with histopathological changes (P=0.011). Compared to the untreated cancer group, we observed no pathological changes and neither a significant alteration in MMP-2 amount in either of healthy controls that were treated with oral and IV dosages of DOX-MTX NPs whilst cancer group showed a high level of MMP-2 expression compared to healthy controls (p<0.001).Taking together our results indicate that DOX-MTX NPs is a safe chemotherapeutic nanodrug that its oral and IV forms possess potent anti-cancer properties on aggressive tumors like OSCC, possibly by affecting the expression of genes that drive tumor invasion and metastasis.

자연집단에서 초파리(Drosophila melanogaster)의 신돌연변이체(Sufr Wings;S f)에 관한 연구 (Studies on a New Wing Mutant (Surf Wings; Srf) of Drosophila melanogaster Extracted from a Wild Population)

  • 姜永善;朴殷浩
    • 한국동물학회지
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    • 제14권2호
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    • pp.75-84
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    • 1971
  • Genetic analysis of a new wing mutant, Surf wings (Srf), was performed. Mutant flies were extracted from a wild population of Drosophila melanogaster at the vicinity of Atomic Energy Research Institute, Seoul in August-September 1969. 1. The distal half of wings of heterozygotes (Srf/+) turned upwards about 40 degree from body axis, but flying ability was not disturbed. They overlap Cy in low frequency when they are grown below $22^{\circ}C$. This resembles with Si or j series, but wing margins are not rolled and diversed. Postscutellars are erected slightly, but they, in general, are not crossed. Any other external pleiotropic effects were not observed. 2. Penetrance and expressivity of both sexes are not complete. Their extents are variable with sex and temperature. These characters show maximum tendencies when the development is made at $22^{\circ}C$ (female: P = 0.996, E = 0.932, male:P = 0.961, E = 0.698). 3. The preliminary locus of Srf was determined to be 66.8 on the right arm of second chromosome by using recessive maker gene cn bw. 4. The homozygous flies(Srf/Srf) have shown perfect lethality. The heterozygotes (Srf/+), on the other hand, have shown to be viable and fertile. Srf chromosomes are kept in a balanced lethal system with Pm chromosomes which are associated with inversions. Hence, it is partially reasonable to suppose that Srf may persist in a natural population by the same mechanism. 5. Allelism test with Cy was also conducted. The fact that combination with Cy in the trans-phase (+ Srf/Cy +) is viable in contrast to the lethality of Srf/Srf and Pm/Pm indicates that Srf and Cy are not functionally allelic.

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