• 제목/요약/키워드: colonization

검색결과 691건 처리시간 0.035초

Effectiveness of Various Pseudomonas spp. and Burkholderia caryophylli Containing ACC-Deaminase for Improving Growth and Yield of Wheat (Triticum aestivum L.)

  • Shaharoona, B.;Jamro, G.M.;Zahir, Z.A.;Arshad, M.;Memon, K.S.
    • Journal of Microbiology and Biotechnology
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    • 제17권8호
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    • pp.1300-1307
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    • 2007
  • This study assessed the possible role of different traits in selected plant growth-promoting rhizobacteria (PGPR) for improving wheat growth and yield under natural conditions. Rhizobacteria exhibiting 1-aminocyclopropane-1-carboxylate (ACC)-deaminase activity were isolated and screened for their growth-promoting activity in wheat under axenic conditions. Five isolates belonging to Pseudomonas and one Burkholderia caryophylli isolate that showed promising performances under axenic conditions were selected and characterized for in vitro ACC-deaminase activity, chitinase activity, auxin production, P solubilization, and root colonization. These isolates were then used as inocula for wheat cultivated under natural conditions in pot and/or field trials. Significant increases in root elongation, root weight, tillers per pot, 1,000-grain weight, and grain and straw yields were observed in response to inoculation with PGPR in the pot trials. Inoculation with these PGPR was also effective under field conditions and increased the wheat growth and yield significantly. However, the efficacy of the strains was inconsistent under the axenic, pot, and field conditions. Pseudomonas fluorescens ($ACC_{50}$), which exhibited a relatively high in vitro ACC-deaminase activity, chitinase activity, auxin production, and P solubilization and more intensive root colonization, was the most efficient isolate under the field conditions. Therefore, these results demonstrated that ACC-deaminase activity is an efficient parameter for the selection of promising PGPR under axenic conditions. However, additional traits of PGPR, including auxin production, chitinase activity, P solubilization, and root colonization, are also important for selecting PGPR as biofertilizers.

Effect of Dispersed and Proximate Inoculation Methods of Glomus etunicatum on Root Colonization of Sorghum-Sudangrass Hybrid

  • Lee, Seonmi;Selvakumar, Gopal;Krishnamoorthy, Ramasamy;Kim, Kiyoon;Choi, Joonho;Sa, Tongmin
    • 한국토양비료학회지
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    • 제46권5호
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    • pp.373-378
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    • 2013
  • Information on the effective application method of arbuscular mycorrhizal fungi (AMF) inoculum is still inadequate. This work was performed to assess two AMF inoculation methods (dispersed and proximate) on root colonization of sorghum-sudangrass hybrid (Sorghum bicolor L.). In dispersed inoculation method, spores were inoculated in 2 kg pots of soil in which 5 day-old seedlings were transplanted and maintained for 50 days. In the proximate inoculation method, spores were first introduced in 500 mL pots where seeds were sown. After 10 days, the seedlings with the 500 mL soil were transferred to 2 kg pots without disturbing the contents. After 50 days of growth, root colonization and arbuscule abundance significantly increased (over 100%) in proximate method of inoculation. Moreover, sorghum-sudangrass hybrid had higher shoot growth (182.5 cm) and Glomalin related soil protein (GRSP) production in proximate method. Nutrient accumulation, particularly total nitrogen (82.61 mg $plant^{-1}$), was also found to be higher in proximate method of inoculation. Our results demonstrate that the proximate method of inoculation may improve the early stage mycorrhizal symbiosis and inoculum performance in Saemangeum reclaimed soil.

도시공공환경의 변인으로서 사회가치인식과 제도의 변화상에 관한 연구 - 근대기 서울의 도시가로환경에 관한 담론을 중심으로 - (The Study on the Correlation between Value Recognition and Urban Design Policy on the Urban Street - Focused on the Spatial Changes in Seoul during the Modern Periods -)

  • 이지영
    • 한국실내디자인학회논문집
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    • 제22권3호
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    • pp.164-173
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    • 2013
  • This study starts from the genealogical analysis of the urban public spaces through local history of Seoul which is significantly different from western countries. The analysis targets the discourse on the urban street, the basic unit of urban tissue and the settlement condition in urban life, which defines urban space-structure among the urban public spaces. And this research classifies and categorizes the value recognition and policy value occurred each period. Based on these, this research defines the progress levels of urban public design policy in Seoul as follows. Results Firstly, 1890's and 1900's was the period of development in commerce and industry, which caused congested and crowded streets. The open port policy allowed the experience of the foreign circumstance, and thus the identity of the urban streets and the value of symbolism come to realize among the society. During the Japanese colonization, urban streets put on modernized images through the urban remodeling out of the context according to the colonization policy. The brand-new values such as publicness and amenity are injected as well as modern regulations by system and authority. From Liberation to 1950's, it performed only street restoration as a repair from war with Japanese colonial system because of the political confusion and administrative vacuum. Finally, each period can be defined as follows. 1890's and 1900's can be defined as 'spontaneous finding the modernization' because urban street was intentionally transformed by the empire. Period of the Japanese colonization can be defined as 'the formation of modernized urban street concept and the compulsion of modernized regulation.' And period of from Liberation to 1950's, can be called as 'the absence of value recognition and maintenance of colonial system.' methodology.

Effect of Hydrogel on Survial of Serratia plymuthica A21-4 in Soils and Plant Disease Suppression

  • Shen, Shun-Shan;Kim, Won-Il;Park, Chang-Seuk
    • The Plant Pathology Journal
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    • 제22권4호
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    • pp.364-368
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    • 2006
  • Survival of biocontrol agents and their effective colonization of rhizhosphere are the essential components for successful disease suppression. The effects of hydrogel supplement on bacterial survival and disease control were evaluated in pot and in the field. Addition of 2% hydrogel material to potting soil resulted in significant enhancement of colonization of biocontrol agent Serratia plymuthica A21-4 both in soil and rhizosphere of pepper plants. Rhizosphere colonization of S. plymuthica A21-4 retrieved from 40 days old pepper seedlings indicated 100 times higher bacterial population in hydrogel treated soil than in ordinary pot soil. The pepper plants sown in hydrogelated potting soil showed higher seed germination rate and the better growth of pepper plant than those in ordinary commercial pot soil. Although the suppression of Phytophthora capsid density in the potting soil by treatment of biocontrol agent A21-4 was not significantly different between in hydrogelated soil and ordinary potting soil, the suppression of Phytophthora blight between two treatments was significantly different. A21-4 treatment in hydrogelated potting soil was completely disease-free while same treatment in ordinary potting soil revealed 36% disease incidence. Our field study under natural disease occurrence also showed significantly less disease incidence(12.3%) in the A21-4 treatment in the hydrogelated soil compared to other treatments. Yield promotion of pepper by the A21-4 treatment in the hydrogelated potting soil was also recognized. Our results indicated that hydrogel amendment with biocontrol agent in pot soil would be a good alternative to protect pepper seedlings and increase plant yield.

Autoimmunity and intestinal colonization by Candida albicans in patients with type 1 diabetes at the time of the diagnosis

  • Gursoy, Semra;Kockar, Tuba;Atik, Sezen Ugan;Onal, Zerrin;Onal, Hasan;Adal, Erdal
    • Clinical and Experimental Pediatrics
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    • 제61권7호
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    • pp.217-220
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    • 2018
  • Purpose: Type 1 diabetes mellitus (T1DM) is a chronic and immune-mediated disease, which is characterized by the progressive destruction of pancreatic beta cells. T1DM precipitates in genetically susceptible individuals through environmental factors. In this study, we aimed to evaluate the impact of autoimmunity and intestinal colonization of Candida albicans on the development of T1DM. Methods: Forty-two patients newly diagnosed with T1DM and 42 healthy subjects were included in this monocentric study. The basic and clinical characteristics of the patients were recorded. T1DM-, thyroid-, and celiac-associated antibodies were evaluated. Stool cultures for C. albicans were performed to assess whether or not gut integrity was impaired in patients with T1DM. Results: The evaluation of T1DM- and thyroid-associated antibodies showed that the prevalences of islet cell antibodies and antithyroperoxidase positivity were higher in the study patients than in the patients in the control group. Furthermore, the direct examination and culture of fresh stool samples revealed that 50% of the patients with T1DM and 23.8% of the control subjects had fungi (C. albicans). Conclusion: Through this study, we suggest that the presence of intestinal C. albicans colonization at the time of the diagnosis of T1DM may indicate impairment of normal intestinal microbiota. We also suggest that there may be a tendency of T1DM in patients with a high prevalence of intestinal C. albicans.

Nature of a Root-Associated Paenibacillus polymyxa from Field-Grown Winter Barley in Korea

  • RYU CHOONG-MIN;KIM JINWOO;CHOI OKHEE;PARK SOO-YOUNG;PARK SEUNG-HWAN;PARK CHANG-SEUK
    • Journal of Microbiology and Biotechnology
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    • 제15권5호
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    • pp.984-991
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    • 2005
  • Soil or seed applications of plant growth-promoting rhizobacteria (PGPR) have been used to enhance growth of several crops as well as to suppress the growth of plant pathogens. In this study, we selected a PGPR strain, Paenibacillus polymyxa strain E681, out of 3,197 heat-stable bacterial isolates from winter wheat and barley roots. Strain E681 inhibited growth of a broad spectrum plant pathogenic fungi in vitro, and treatment of cucumber seed with E681 reduced incidence of damping-off disease caused by Pythium ultimum, Rhizoctonia solani, or Fusarium oxysporum. When inoculated onto seeds as vegetative cells or as endospores, E681 colonized whole cucumber root systems and root tips. Different temperatures such as $20^{\circ}C\;and\;30^{\circ}C$ did not affect root colonization by strain E681. This colonization was associated with a consistent increase in foliar growth of cucumber in the greenhouse. These results indicate that strain E681 is a promising PGPR strain for application to agricultural systems, particularly during the winter season.

신경외과 병동에 적용한 Vancomycin 내성 장구균의 감염관리 전략효과 및 균집락의 위험인자 분석 (Effects of Infection Control Strategies & Analysis of Risk Factors for Vancomycin Resistant Enterococci)

  • 홍혜경;이꽃실;박성춘;정은경;박미라;김세철
    • 한국의료질향상학회지
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    • 제19권1호
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    • pp.30-42
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    • 2013
  • Objectives: This study was intended to check if the "Creating Clean Wards" project, which is an innovative reinforced campaign activity targeting infection control strategies and active surveillance cultures for VRE (vancomycin resistant enterococci) high-risk patients to be admitted in the NS (neuro-surgery) wards, would be reduced the incidence rates of VRE acquisition, transmission rates. Methods: 75 subjects of the VRE high-risk patients were surveyed by carrying out active surveillance cultures of VRE colonization 11 times from January to March, 2012. And the retrospective study was conducted dividing them into two groups. Results: The incidence rates of VRE acquisition was reduced to 3.67 cases per 1,000 patients day in the control group and to 2.88 cases in experimental group, which was not statistically significant (p = .753). VRE transmission rates of 0.0015 per day before the project tended to increase to 0.0019, although not statistically significant (p = .650). As a result of multivariate analysis with regard to using glycopeptide antibiotics in order to find out risk factors of VRE colonization, the patients who had been treated with glycopeptide until VRE colonization showed 274.41 times higher rate. Conclusion : For effective VRE infection control in NS wards, We should carry out active surveillance culture regularly, especially patient of using glycopeptide. And block the spread of VRE by strengthening infection control through the strict isolation and the changed mind-set of members motivated by the "Creating Clean Wards" campaign.

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