• Title/Summary/Keyword: Soil bacteria

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Effects of Organic Matters Decomposed by Microbial Activity on Yield of Leaf Lettuce Under Protected Cultivation (미생물 유기질비료의 시용이 상추의 수량에 미치는 영향)

  • 김경제;김석균
    • Korean Journal of Organic Agriculture
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    • v.8 no.1
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    • pp.131-137
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    • 1999
  • This study was conducted to investigate the effects of microbial fertilizers on the yields of Leaf lettuce, chemical components of soil, and the microbial floras. Six micriobial fertilizers, MPK+Husk+Palma, Husk+Palma, MPK+Compost, Compost, Bio livestock cattle system(BLCS) cattle dropping, and Tomi, were used. All of the microbial fertilizers were tend to increase yields of Leaf lettuce, especially MPK+Husk+Palma treatment was most effective. In a chemical components of soil, concentrations of K, Mg were increased with Tomi treatment, however, the other concentrations of soil chemical components were not different. In a microbial floras of soil, Tomi, Husk+Palma, and MPK+Husk+Palma treated plots increased in numbers of total bacteria and bacillus. Tomi treated plot increased in numbers of actinomycetes and fungi, also. The other microbial floras of soil were not different, however. The microbial fertilizers may affect the useful microbial floras, therefore, it would be increase yield of Leaf lettuce treated with them.

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Steel Pile Corrosion in Potential Acid Sulfate Soil (잠재성 특이산성토중 강관말뚝의 부식)

  • Lee, Seung-Heon;Park, Mi-Hyeun;Yoon, Kyung-Sup
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 2003.10a
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    • pp.559-562
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    • 2003
  • The results and discussions of surveyed case site at constructed steel pile in potential acid sulfate soil were as follows. Topography at surveyed site was local alluvial valley and that site soils was classified as BanGog and YuGye series as detailed soil surveyed results in RDA and soil texture was Clay/Clay Loam. Soils pH was neutral, which was average 7.5 but much decreased to average 4.2 after $H_2O_2$ treatment. Organic matter and sulfate ions contents were very rich. The corrosion was severe at ground water fluctuation depth. Deposits colored black were attached to steel pile surface, which because of violent reaction in treatment HCI solution, were guessed as corrosion products (FeS) reduced by sulfate reducing bacteria(SRB). Consequently, main cause was thought microbiologically induced corrosion at this site where there is ground water fluctuation occurring oxidation and reduction reactions in turn and the soil is potential acid sulfate soil.

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Analysis of Species Variety and Physiological Characteristics of Denitrifying Oligotrophic Bacteria Isolated from the Specific Environment in Korea (국내 특수 생태환경의 탈질 저영양 세균의 종 다양성 및 생리적 특성 분석)

  • Lee, Chang-Muk;Weon, Hang-Yeon;Kwon, Soon-Wo;Kang, Han-Chul;Koo, Bon-Sung;Yoon, Sang-Hong
    • Microbiology and Biotechnology Letters
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    • v.39 no.3
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    • pp.210-217
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    • 2011
  • In an effort to isolate novel bacteria for the bioremediation of over-fertilized soils, we identified 135 denitrifying cells out of 3,471 oligotrophic bacteria pools (3.9%) using a denitrification medium supplemented with potassium nitrate as the sole nitrogen source. Soil samples were taken from ecologically well-conserved areas, including a mountain swamp around the demilitarized zone (Yongneup), two ecoparks (Upo and the Mujechi bog), and ten representative islands around the Korean peninsula (Jejudo, Daecheongdo, Socheongdo, Baekryeongdo, Ulrungdo, Dokdo, Geomundo, Hongdo, Huksando and Yeonpyeongdo). All of the 135 bacteria produced nitrogen gas from the denitrification medium, and were proved to be nitrate reductase positive by API-BioLog tests. Phylogenetic analysis using 16S rDNA sequences revealed that the 135 bacteria consisted of 44 different genera. Along with the most prominent, Proteobacteria (87.4%), we identified denitrifying bacteria from Firmicutes (9.4%), Actinobacteria (2.4%), and Bacteroidetes (0.8%). Physiological analyses of the 44 representative denitrifying bacteria, under various pH levels, growth temperatures and salt stresses, revealed 12 favorable denitrifying strains for soil bioremediation.

Bacterial Effects on Geochemical Behavior of Elements : An Overview on Recent Geomicrobiological Issues (원소의 지구화학적 거동에 미치는 박테리아의 영향 : 지구미생물학의 최근 연구 동향)

  • 이종운;전효택
    • Economic and Environmental Geology
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    • v.33 no.5
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    • pp.353-365
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    • 2000
  • After their first appearance on Earth, bacteria have exerted significant influence on geochemical behavior of elements. Numerous evidence of their control on geochemistry through geologic history has been observed in a variety of natural environments. They have mediated weathering rate, formation of secondary minerals, redox transformation of metals and metalloids, and thus global cycling of elements. Such ability of bacteria receives so considerable attention from microbiologists, mineralogists, geologists, soil scientists, limnologists, oceanographers, and atmospheric scientists as well as geochemists that a new and interdisciplinary field of research called 'geomicrobiology' is currently expanding. Some recent subjects of geomicrobiology which are studied extensively are as follows: 1) Functional groups distributed on bacterial cell walls adsorb dissolved cations onto cell surfaces by electrostatic surface complexation, which is followed by hydrous mineral formation. 2) Dissimilatory metal reducing bacteria conserve energy to support growth by oxidation of organic matter coupled to reduction of some oxidized metals and/or metalloids. They can be effectively used in remediating environments contaminated with U, As, Se, and Cr. 3) Bacteria increase the rate of mineral dissolution by excreting proton and ligands such as organic acids into aqueous system. 4) Thorough investigation on the effects of biofilm on geochemical processes is needed, because most bacteria are adsorbed on solid substrates and form biofilms in natural settings.

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Effect of the Herbicide Bentazon on Nitrification, and on Numbers of Bacteria and Fungi in the Soil (제초제(除草劑) Bentazon이 질산화작용(窒酸化作用) 및 토양미생물(土壤微生物)의 균수(菌數)에 미치는 영향(影響))

  • Kang, Kyu-Young
    • Applied Biological Chemistry
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    • v.21 no.2
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    • pp.81-83
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    • 1978
  • The effect of bentazon(3-isopropyl-1H-2,1,3-benzothiadiazine-(4)-3H-one-2,2-dioxide) at 50, 200ppm on nitrification of 100ppm applied $NH_4-N$, and on the numbers of nitrite-oxidizing bacteria, and on total bacterial and fungal populations were studied in a soil for six weeks. The herbicide retarded nitrification with increasing its treatment, which was coincident with the decrease of nitrite-oxidinzing bacterial populations. Bentazon treatment in a soil caused the decrease of total bacterial populations and inversely the increase of fungal populations for 2 weeks.

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