Elucidation of the nanomechanism of bacterial adhesion for controlling the initial stage of biofilm formation
| Project/Area Number |
16360409
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Biofunction/Bioprocess
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| Research Institution | Nagoya Institute of Technology |
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Principal Investigator |
HORI Katsutoshi Nagoya Institute of Technology, Graduate School of Engineering, Associate Professor (50302956)
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| Co-Investigator(Kenkyū-buntansha) |
TANJI Yasunori Tokyo Institute of Technology, Graduate School of Bioscience and Biotechnology, Associate Professor (00282848)
MIYANAGA Kazuhiko Tokyo Institute of Technology, Graduate School of Bioscience and Biotechnology, Research Associate (40323810)
UNNO Hajime Tokyo Institute of Technology, Graduate School of Bioscience and Biotechnology, Professor (10087471)
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| Project Period (FY) |
2004 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥15,100,000 (Direct Cost: ¥15,100,000)
Fiscal Year 2006: ¥2,600,000 (Direct Cost: ¥2,600,000)
Fiscal Year 2005: ¥5,000,000 (Direct Cost: ¥5,000,000)
Fiscal Year 2004: ¥7,500,000 (Direct Cost: ¥7,500,000)
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| Keywords | biofilm / microbial adhesion / bacterial nanofiber / autotransporter / adhesin / pili / Acinetobacter / adhesive protein / 細胞接着 / セルアペンデージ / DLVO理論 / 付着因子 / FE-SEM |
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| Research Abstract |
The adhesiveness of the toluene-degrading bacterium, Acinetobacter sp. Tol 5, is noteworthy so that inner walls of plastic tips and pipettes are coated with the cells at once by just sampling of them. We found two morphological types of bacterial nanofibers that have a function of connecting the Tol 5 cells to a substratum, an anchor-like fiber and a pili-like fiber. Contemporary electron microscopy techniques revealed that the former extends straight to the substratum without branching and tethers the cell body at its end from distances of several hundred nanometers, whereas the latter attaches to the substratum in multiple places, fixing the cell at much shorter distances.
We obtained a less-adhesive mutant, Tol 5 T1, which lost both types of nanofibers. Wild-type cells attained irreversible adhesion to polyurethane carriers within 30 s, while adhesion of T1 cells was still reversible at that time. While T1 showed decreased adhesion with decreasing ionic strength and did not adhere at all at 0.015 mM, adhesion of the wild type was fully independent of ionic strength. This implies that WT cell adhesion via the long appendages does not follow the trends predicted by DLVO theory, whereas T1 cells, which lack these long appendages, adhere in a manner consistent with DLVO theory.
We revealed that in T1, the gene encoding a novel protein belonging to the autotransporter adhesin is disrupted and the expression level of type 1 pili descends. It was also revealed that the bald mutant T1 cells lack self-agglutinating property and adhere to hydrocarbon surfaces in a monolayer, which can be described by the Langmuir adsorption isotherm.
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Report
(4 results)
Research Products
(30 results)
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[Book] バイオフィルムの基礎と制御2008
Author(s)
堀 克敏(分担)
Total Pages
399
Publisher
エヌ・ティー・エス
Description
「研究成果報告書概要(和文)」より
Related Report
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