A novel metal-import system in the pit-forming bacterium and its application for recovery of radioactive compounds and rare metals

2015 Fiscal Year Final Research Report

• Project/Area Number: 26660062
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Applied microbiology
• Research Institution: Kyoto University
• Principal Investigator: Hashimoto Wataru 京都大学, (連合)農学研究科(研究院), 教授 (30273519)
• Co-Investigator(Kenkyū-buntansha): MURATA Kousaku 摂南大学, 理工学部, 教授 (90142299)
• Project Period (FY): 2014-04-01 – 2016-03-31
• Keywords: 細菌 / アルギン酸 / レアメタル / 輸送体 / 電子顕微鏡 / 原子間力顕微鏡 / X線結晶構造解析 / 示差走査型蛍光定量法

Outline of Final Research Achievements

A gram-negative bacterium, Sphingomonas sp. A1, incorporates metal-chelating alginates. In this study, structure and function of the bacterial cell surface and alginate-binding protein Algp7 were analyzed by microscopy, differential scanning fluorimetry, or X-ray crystallography. The bacterial cells attached to alginate-calcium gels formed a pit on the cell surface. The pit showed about 100 nm in depth and high electrical potential. Algp7 exhibited a capability to bind rare metals such as Sm3+ and Tl3+, and to associate with alginate at the positively charged cluster formed by Lys68 and Lys69. These results suggest that the high electrical potential in the pit contributes to concentration of negatively charged alginate and Algp7 is applicable for recovery of rare metals.

Free Research Field

応用微生物学