• 제목/요약/키워드: soil microbiology

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Streptomyces sp. 가 생산하는 항진균성 항생물질에 관한 연구(제 1 보) 생산균주의 선별과 항진균성 항생물질의 분리정제 (Studies on the Antifungal Antibiotics Produced by a Streptomyces sp. (Part 1) Selection of the Antibiotics Producing Organism and Isolation of the Antibiotics)

  • 배무;고영희
    • 한국미생물·생명공학회지
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    • 제10권1호
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    • pp.33-37
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    • 1982
  • 벼 교엽병 방제를 위한 새로운 항진균성 항물질을 개발하기 위하여 우리나라 전국 각지역에서 임의로 채취한 1600여점의 토양시료에서 방선균 1300여주를 분리하고 액침배양법, Denroid test, green house test 등으로 벼에 대한 생리독성이 없으면서 벼 교엽병에 치료효과를 나타내는 방선균 1주를 소요산 부근의 토양시료에서 분리, 선정하였다. 분러선정균의 배양액에서 항진균성 항생물로서 연한 황색의 무정형 분말과 백색침상결정의 두가지를 분리, 정제하였다.

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Spatial Physicochemical and Metagenomic Analysis of Desert Environment

  • Sivakala, Kunjukrishnan Kamalakshi;Jose, Polpass Arul;Anandham, Rangasamy;Thinesh, Thangathurai;Jebakumar, Solomon Robinson David;Samaddar, Sandipan;Chatterjee, Poulami;Sivakumar, Natesan;Sa, Tongmin
    • Journal of Microbiology and Biotechnology
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    • 제28권9호
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    • pp.1517-1526
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    • 2018
  • Investigating bacterial diversity and its metabolic capabilities is crucial for interpreting the ecological patterns in a desert environment and assessing the presence of exploitable microbial resources. In this study, we evaluated the spatial heterogeneity of physicochemical parameters, soil bacterial diversity and metabolic adaptation at meter scale. Soil samples were collected from two quadrats of a desert (Thar Desert, India) with a hot, arid climate, very little rainfall and extreme temperatures. Analysis of physico-chemical parameters and subsequent variance analysis (p-values < 0.05) revealed that sulfate, potassium and magnesium ions were the most variable between the quadrats. Microbial diversity of the two quadrats was studied using Illumina bar-coded sequencing by targeting V3-V4 regions of 16S rDNA. As for the results, 702504 high-quality sequence reads, assigned to 173 operational taxonomic units (OTUs) at species level, were examined. The most abundant phyla in both quadrats were Actinobacteria (38.72%), Proteobacteria (32.94%), and Acidobacteria (9.24%). At genus level, Gaiella represented highest prevalence, followed by Streptomyces, Solirubrobacter, Aciditerrimonas, Geminicoccus, Geodermatophilus, Microvirga, and Rubrobacter. Between the quadrats, significant difference (p-values < 0.05) was found in the abundance of Aciditerrimonas, Geodermatophilus, Geminicoccus, Ilumatobacter, Marmoricola, Nakamurella, and Solirubrobacter. Metabolic functional mapping revealed diverse biological activities, and was significantly correlated with physicochemical parameters. The results revealed spatial variation of ions, microbial abundance and functional attributes in the studied quadrats, and patchy nature in local scale. Interestingly, abundance of the biotechnologically important phylum Actinobacteria, with large proposition of unclassified species in the desert, suggested that this arid environment is a promising site for bioprospection.

제주도 야생버섯 hyphosphere 토양에서 분리된 국내 미기록 진균 11종 보고 (Eleven previously unrecorded fungal species isolated from hyphosphere soil supporting wild mushrooms in Jeju Island)

  • 노형진;김예인;이동형;고평열;박혜성;이강효;김성환
    • 한국버섯학회지
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    • 제21권4호
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    • pp.228-240
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    • 2023
  • 야생버섯의 결실에 미치는 미생물의 영향을 파악하기 위하여 제주도 곶자왈 지역에서 발견된 야생버섯, 끈적버섯 (Cortinarius violaceus), 달걀버섯 (Amanita hemibapha), 색시졸각버섯 (Laccaria vinacelavellanea), 흰알광대버섯 (Amanita verna)의 근권토양 균류를 조사하였다. 형태학적 특성 조사와 ITS, LSU rDNA, β-tubulin 유전자 서열에 대한 분자생물학적 분석을 바탕으로 동정하는 과정에서 국내 미기록 진균 11종을 분리하였다. 이들 진균은 Arthrinium kogelbergensis, Kalmusia longisporum, Keithomyces carneum, Neopyrenochaeta cercidis, Penicillium ranomafanaense, Phomatodes nebulosa, Pyrenochaeta nobilis, Tollypocladium album, Talaromyces kendrickii, Talaromyces qii, Umbelopsis gibberispora이다. 이들 11종에 진균에 대한 형태적 특성과 계통발생학적 위치를 기술하였다.

토양 특성에 따른 다양한 희소방선균의 분리 (Isolation of Rare Actinomycetes on Various Types of Soil)

  • 김창진;이강현;아끼라 시마즈;권오성;박동진
    • 한국미생물·생명공학회지
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    • 제23권1호
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    • pp.36-42
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    • 1995
  • Actinomycetes occur in a wide range of environments and many more actinomycetes remain to be detected in the natural environment. In isolation stages, selection of the environment as a source of useful isolates is important. Two hundred and eighteen strains were isolated on Bennet's agar and 346 strains were on humic acid-vitamin agar from five each paddy field, field, forest, grass land, riverside soil samples. These isolates were identified to the genus level based on morphological and physiological characteristics. Among them, 386 strains were Streptomyces, 49 strain were Nocardia, 35 strains were Microbispora and Micromonospora each, 15 strains were Nocardiopsis, 13 strains were Actinomadura, 10 strains were Streptosporangium, and the others were isolated rarely. According to soil type, Nocardia, Micromonospora, Microbispora and Streptosporangium were dominant in paddy field, Microbispora Nocardia, Nocardioides and Micromonospora were dominant in field, Nocardia, Micromonospora, Microbispora and Actinomadura were dominant in grass land, Nocardia, Micromonospora and Microbispora were dominant in forest, Nocardia, Microbispora and Micromonospora were dominant in riverside. Generally, Nocardia, Micromonospora, Microbispora and Actinomadura were isolated in all kinds of soils, Streptosporangium were paddy field, Dactylosporangium were forest, Nocardiopsis were field, forest and riverside.

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Genetic and Physiological Characterization of Oxytetracycline-Resistant Bacteria from Giant Prawn Farms

  • Heepngoen, Pimpak;Sajjaphan, Kannika;Ferguson, John A.;Sadowsky, Michael J.
    • Journal of Microbiology and Biotechnology
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    • 제18권2호
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    • pp.199-206
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    • 2008
  • Four hundred and thirteen oxytetracycline-resistant bacteria were recovered from six freshwater giant prawn farms with a history of oxytetracycline use. Most oxytetracycline-resistant isolates were Gram-negative bacteria. Six groups of oxytetracycline-resistant bacteria were classified using cluster analysis based on a comparison of levels of oxytetracycline resistance. Complex fingerprint patterns were obtained for 71 isolates studied. In general, the band patterns of isolates from different ponds were very similar, and the data indicated that the isolates were closely related. The exploration for cross-resistance found that most of the 71 oxytetracycline-resistant isolates were also resistant to tetracycline and chlortetracycline, but had a relatively low resistance to doxycycline. Many isolates showed higher chlortetracycline resistance than oxytetracycline resistance. Additionally, the oxytetracycline-resistant isolates were examined for the presence of tetracycline resistance (tet) genes. Fifty percent of the isolates carried one of the 14 known tet genes examined. The most common determinants were TetA and TetD. However, TetB, TetC, TetE, TetK, TetL, and TetM were also found with various frequencies.

Substrate-Dependent Auxin Production by Rhizobium phaseoli Improves the Growth and Yield of Vigna radiata L. Under Salt Stress Conditions

  • Zahir, Z.A.;Shah, M. Kashif;Naveed, M.;Akhter, M. Javed
    • Journal of Microbiology and Biotechnology
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    • 제20권9호
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    • pp.1288-1294
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    • 2010
  • Rhizobium phaseoli strains were isolated from the mung bean (Vigna radiata L.) nodules, and the most salt tolerant and high auxin producing rhizobial isolate N20 was evaluated in the presence and absence of L-tryptophan (L-TRP) for improving the growth and yield of mung bean under saline conditions in a pot experiment. Mung bean seeds were inoculated with peat-based inoculum and NP fertilizers were applied at 30-60 kg/ha, respectively. Results revealed that imposition of salinity reduced the growth and yield of mung bean. On the contrary, the separate application of L-TRP and Rhizobium appeared to mitigate the adverse effects of salt stress. However, their combined application produced more pronounced effects and increased the plant height (28.2%), number of nodules per plant (71.4%), plant biomass (61.2%), grain yield (65.3%), and grain nitrogen concentration (22.4%) compared with untreated control. The growth promotion effect might be due to higher auxin production in the rhizosphere and improved mineral uptake that reduced the adverse effects of salinity. The results imply that supplementing Rhizobium inoculation with L-TRP could be a useful approach for improving the growth and yield of mung bean under salt stress conditions.

Degradation of Phenanthrene by Bacterial Strains Isolated from Soil in Oil Refinery Fields in Korea

  • KIM JEONG DONG;SHIM SU HYEUN;LEE CHOUL GYUN
    • Journal of Microbiology and Biotechnology
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    • 제15권2호
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    • pp.337-345
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    • 2005
  • The degradation of phenanthrene, a model PAH compound, by microorganisms either in the mixed culture or individual strain, isolated from oil-contaminated soil in oil refmery vicinity sites, was examined. The effects of pH, temperature, initial concentration of phenanthrene, and the addition of carbon sources on biodegradation potential were also investigated. Results showed that soil samples collected from four oil refinery sites in Korea had different degrees of PAH contamination and different indigenous phenanthrene-degrading microorganisms. The optimal conditions for phenanthrene biodegradation were determined to be 30$^{circ}C$ and pH 7.0. A significantly positive relationship was observed between the microbial growth and the rate of phenanthrene degradation. However, the phenanthrene biodegradation capability of the mixed culture was not related to the degree of PAH contamination in soil. In low phenanthrene concentration, the growth and biodegradation rates of the mixed cultures did not increase over those of the individual strain, especially IC10. High concentration of phenanthrene inhibited the growth of microbial strains and biodegradation of phenanthrene, but was less inhibitory on the mixed culture. Finally, when non-ionic surfactants such as Brij 30 and Brij 35 were present at the level above critical micelle concentrations (CMCs), phenanthrene degradation was completely inhibited and delayed by the addition of Triton X100 and Triton N101.

Production, Purification, and Characterization of Antifungal Metabolite from Pseudomonas aeruginosa SD12, a New Strain Obtained from Tannery Waste Polluted Soil

  • Dharni, Seema;Alam, Mansoor;Kalani, Komal;Abdul-Khaliq, Abdul-Khaliq;Samad, Abdul;Srivastava, Santosh Kumar;Patra, Dharani Dhar
    • Journal of Microbiology and Biotechnology
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    • 제22권5호
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    • pp.674-683
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    • 2012
  • A new strain, SD12, was isolated from tannery waste polluted soil and identified as Pseudomonas aeruginosa on the basis of phenotypic traits and by comparison of 16S rRNA sequences. This bacterium exhibited broad-spectrum antagonistic activity against phytopathogenic fungi. The strain produced phosphatases, cellulases, proteases, pectinases, and HCN and also retained its ability to produce hydroxamate-type siderophore. A bioactive metabolite was isolated from P. aeruginosa SD12 and was characterized as 1-hydroxyphenazine ((1-OH-PHZ) by nuclear magnetic resonance (NMR) spectral analysis. The strain was used as a biocontrol agent against root rot and wilt disease of pyrethrum caused by Rhizoctonia solani. The stain is also reported to increase the growth and biomass of Plantago ovata. The purified compound, 1-hydroxyphenazine, also showed broad-spectrum antagonistic activity towards a range of phytopathogenic fungi, which is the first report of its kind.