• 제목/요약/키워드: Bio Environment

검색결과 3,731건 처리시간 0.035초

Suppression of Melanose Caused by Diaporthe citri on Citrus Leaves Pretreated with Bio-sulfur

  • Shin, Yong Ho;Ko, Eun Ju;Kim, Su Jeong;Hyun, He Nam;Jeun, Yong Chull
    • The Plant Pathology Journal
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    • 제35권5호
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    • pp.417-424
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    • 2019
  • Melanose, caused by Diaporthe citri, is one of severe diseases in citrus, a major economic resource in Jeju island. To reduce the usage amount of organic synthetic fungicide, bio-sulfur was tested as an alternative chemical to control citrus melanose in the present study. Direct antifungal activity of bio-sulfur against D. citri was determined through in vitro experiment using artificial nutrient media. Disease severity of melanose on bio-sulfur pretreated citrus leaves was lower than that on untreated ones. To illustrate the mechanism of disease suppression by bio-sulfur, infection structures were observed with a fluorescent microscope and a scanning electron microscope. In fluorescent microscopic observation, most conidia rarely germinated. In addition, hyphal growth on leaves pretreated with bio-sulfur was inhibited compared to that on untreated ones. In scanning electron microscope images of bio-sulfur pretreated leaves, surfaces of most conidia were shrunk while hyphae were morphologically changed and frequently branched. Such microscopic observations were also found for leaves pretreated with a commercial fungicide Dithianon. These results suggest that bio-sulfur may be used to control citrus melanose as an environment friendly alternative to organic synthetic fungicides

Cloning, Expression, and Functional Characterization of the Dunaliella salina 5-enolpyruvylshikimate-3-phosphate Synthase Gene in Escherichia coli

  • Yi, Yi;Qiao, Dairong;Bai, Linhan;Xu, Hui;Li, Ya;Wang, Xiaolin;Cao, Yi
    • Journal of Microbiology
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    • 제45권2호
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    • pp.153-157
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    • 2007
  • 5-enolpyruvylshikimate-3-phosphate synthase (EPSP synthase, EC 2.5.1.19) is the sixth enzyme in the shikimate pathway which is essential for the synthesis of aromatic amino acids and many secondary metabolites. The enzyme is widely involved in glyphosate tolerant transgenic plants because it is the primary target of the nonselective herbicide glyphosate. In this study, the Dunaliella salina EPSP synthase gene was cloned by RT-PCR approach. It contains an open reading frame encoding a protein of 514 amino acids with a calculated molecular weight of 54.6 KDa. The derived amino acid sequence showed high homology with other EPSP synthases. The Dunaliella salina EPSP synthase gene was expressed in Escherichia coli and the recombinant EPSP synthase were identified by functional complementation assay.

생물학적 하·폐수처리 공정에서 생물촉진제 첨가의 영향 (Effects of Bio-stimulant Addition on Biological Wastewater Treatment Processes)

  • 이석헌;정진영;박기영
    • 한국물환경학회지
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    • 제21권4호
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    • pp.398-402
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    • 2005
  • The enzyme Xeronine was investigated as a microbial activating substance in biological wastewater treatment processes. Xeronine as bio-stimulant was injected in the anaerobic sludge and the activated sludge treating wastewater in order to examine the effect of hidden benefits. Bio-stimulant did not show significant improvement of anaerobic treatablity. In the aerobic system, higher bio-stimulant dose condition resulted in slightly more removal of nitrogen and phosphorus. Floc aggregation and zone settling velocity as solid-liquid separation factors in activated sludge systems was enhanced by bio-stimulant. Effects of bio-stimulants injection on improvement of water quality and microbial activity did not clear in terms of normal operation conditions.

Effect of organic fertilizer mixed with dehydrated food waste powder on growth of leaf lettuce

  • Yoo, Jun-Hyuk;Kim, Jae-Hong;Lee, Jae-Han;Chun, Jin-Hyuk;Deogratius, Luyima;Kang, Yun-Gu;Woo, Hyun-Nyung;Oh, Taek-Keun;Kim, Seong-Heon
    • 농업과학연구
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    • 제47권4호
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    • pp.1021-1027
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    • 2020
  • The amount of food waste generated in Republic of Korea has been increasing alongside an increasing population and booming economy as such, research on effective treatment and recycling is required. Food waste recycling is complicated by its inferior characteristics such as high levels of water and concern that its continuous application to farmland can lead to salt accumulation and concomitant damage crops. In the present study, therefore, dehydrated food waste powder (FWP), which contains a large amount of organic matter and nutrients, but which may require additional improvements was mixed in various ratios with organic fertilizers and the mixtures were tested for their effects on the growth of the leaf lettuce. A control was set up with inorganic fertilizers alone while a treatment with only FWP was also included. The mixture of FWP and organic fertilizers produced better leaf lettuce growth in all the treatments than the control and FWP. The fresh weight of the leaf lettuce produced with a mixture containing 60% FWP was 50% higher than that of the control. The results from this study indicate, therefore, that FWP mixed with other organic supplements in appropriate amounts positively impacts crop growth and development.

Bio-Sulfur Pre-Treatment Suppresses Anthracnose on Cucumber Leaves Inoculated with Colletotrichum orbiculare

  • Ko, Eun Ju;Shin, Yong Ho;Hyun, He Nam;Song, Hyo Soon;Hong, Jeum Kyu;Jeun, Yong Chull
    • Mycobiology
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    • 제47권3호
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    • pp.308-318
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    • 2019
  • Bio-sulfur can be produced in the process of desulfurization from a landfill and collected by some microorganism such as Thiobacillus sp. as a sulfur element. In order to investigate practical use of bio-sulfur as an agent for controlling plant disease, in vitro antifungal activity of bio-sulfur was tested against Colletotrichum orbiculare known to cause cucumber anthracnose. Efficacy of bio-sulfur for suppressing anthracnose disease was also evaluated in vivo using cucumber leaves. Mycelial growth of C. orbiculare on medium containing bio-sulfur was inhibited. Disease severity of cucumber leaves pre-treated with bio-sulfur was significantly decreased compared to that of untreated ones. To illustrate how bio-sulfur could suppress anthracnose disease, structures of cucumber leaves infected with C. orbiculare were observed under a fluorescent microscope and a scanning electron microscope (SEM). Cucumber leaves pre-treated with bio-sulfur showed a low rate of appressorium formation whereas untreated ones showed abundant appressoria. Shrunk fungal hyphae were mostly observed on bio-sulfur-pretreated leaves by SEM. Similar results were observed on leaves pre-treated with a commercial fungicide Benomyl(R). These results suggest that inhibition of appressorium formation of C. orbiculare by bio-sulfur may contribute to its suppression of cucumber anthracnose.