• Title/Summary/Keyword: microbial characterization

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Selection and Directed Evolution of New Microbial Biocatalysts and Their Application to Organic Synthesis

  • Asano, Yasuhisa
    • Journal of Applied Biological Chemistry
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    • v.43 no.4
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    • pp.207-210
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    • 2000
  • As a typical example of the screening for a microbial biocatalyst from nature, isolation of nitrilesynthesizing microorganisms, characterization of a new enzyme aldoxime dehydratase, and its function in the aldoxime-nitrile pathway are introduced. Catalytic properties of some of our enzymes were improved through a direct evolutionary approach.

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Characterization of Microbial Community in Biological Wastewater Treatment System Using Respiratory Quinone Profiles

  • Lim Byung-Ran;Ahn Kyu-Hong;Lee Yonghun
    • Proceedings of the Microbiological Society of Korea Conference
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    • 2003.05a
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    • pp.111-114
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    • 2003
  • The dynamics of microbial community structure of the various domestic wastewater treatment processes were examined using a novel approach of quinone profiles. The compositions of microbial quinone of 5 sites fer plant and lab-scale activated sludge were analyzed. More than 14 kinds of quinones were observed in the activated sludges tested in this study. The microbial community structure of the plant activated sludge processes a little differed from that of the lab-scale submerged MBR systems. The dominant quinones were UQ-8, UQ-10 followed $MK-8(H_4)$, MK-7 and MK-6. The molar ratio of ubiquinones to menaquinones (UQ/MK) changed from 0.81 to 1.9, indicating that aerobic bacteria dominated the microbial community of the activated sludge examined. The microbial diversity of the activated sludges calculated from the all quinone compositions was 9.5-11.9 and the microbial equability of the activated sludges was 0.64-0.79.

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Cloning and Characterization of a Novel ${\alpha}$-Amylase from a Fecal Microbial Metagenome

  • Xu, Bo;Yang, Fuya;Xiong, Caiyun;Li, Junjun;Tang, Xianghua;Zhou, Junpei;Xie, Zhenrong;Ding, Junmei;Yang, Yunjuan;Huang, Zunxi
    • Journal of Microbiology and Biotechnology
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    • v.24 no.4
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    • pp.447-452
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    • 2014
  • To isolate novel and useful microbial enzymes from uncultured gastrointestinal microorganisms, a fecal microbial metagenomic library of the pygmy loris was constructed. The library was screened for amylolytic activity, and 8 of 50,000 recombinant clones showed amylolytic activity. Subcloning and sequence analysis of a positive clone led to the identification a novel gene (amyPL) coding for ${\alpha}$-amylase. AmyPL was expressed in Escherichia coli BL21 (DE3) and the purified AmyPL was enzymatically characterized. This study is the first to report the molecular and biochemical characterization of a novel ${\alpha}$-amylase from a gastrointestinal metagenomic library.

Microbial Forensics: Bioterrorism and Biocrime

  • Eom, Yong-Bin
    • Biomedical Science Letters
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    • v.24 no.2
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    • pp.55-63
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    • 2018
  • Microbes and their toxins can be bioweapons that bioterrorists use them to commit bioterrorism and biocrime. Due to the potential and relative ease of the bioattack, life-threat pathogenic agents (bacteria, viruses, and toxins) as bioweapon revealed the need for a new field of microbial forensics. Microbial forensics is a new scientific discipline combining microbiology and forensic science, which is focused on characterization of evidence from a bioterrorism, biocrime, and an inadvertent release of biothreat agents. The sophisticated analytical tool and knowledge of microbial forensics can provide investigative leads and help determine who was responsible for the biocrime, the source of the bioweapon, and how and where the bioweapon was produced. Among the fields of microbial forensics, this paper will briefly describe evidence collection, handling, packaging, transportation, storage, analytical methods of evidence, and review microbial forensics as a response to bioterrorism and biocrime.

Characterization and Identification of Streptomyces SL20209 Producing Valistatin and des-Asp$^4$-Amastatin, Two Inhibitors of Aminopeptidase M. (Aminopeptidase M 저해제인 Valistatin과 des-Asp$^4$-Amastatin을 생산하는 방선균 SL20209의 특성 및 동정)

  • Ko, Hack-Ryong;Chun, Hyo-Kon;Chung, Myung-Chul;Suh, Hyun-Hyo;Kim, Hong-Joong;Park, Yong-Ha;Kho, Yung-Hee
    • Microbiology and Biotechnology Letters
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    • v.24 no.1
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    • pp.1-8
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    • 1996
  • Characterization and numerical identification were carried out for an actinomycetes SL20209. Morphological, cultural and physiological perperties of SL20209 which porduced valistatin and des-$asp^4$-amastatin as inhibitors of aminopeptidase M were evaluated. The isolate was identified to be the genus of Streptomyces. Fourty-three taxonomic units were analysed by using a TAXON program. The isolate was classified into the major cluster 29 of Streptomyces and best-matched to Streptomyces griseoplanus.

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