Analysis of the possibility of siderophore-mediated silicon uptake

2018 Fiscal Year Final Research Report

• Project/Area Number: 16H04900
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Applied microbiology
• Research Institution: Hiroshima University
• Principal Investigator: Ikeda Takeshi 広島大学, 先端物質科学研究科, 助教 (10505754)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 細菌 / 胞子 / ケイ素

Outline of Final Research Achievements

Bacillus cereus and its close relatives take up soluble silicate from the environment and accumulate it as insoluble silica in and around the spore coat layer. However, the mechanism underlying silicate uptake has not been clarified. Recently, it has been reported that siderophores, natural iron-chelating compounds secreted by microorganisms, can form a complex with silicon. We hypothesized that siderophores might be involved in silicate uptake in B. cereus. The disruption of one of the two siderophore biosynthesis operons resulted in significant decrease in silicate uptake. However, medium exchange during cultivation did not affect silicate uptake, suggesting that siderophore-mediated transport is not a major route of silicate uptake.

Free Research Field

生物工学

Academic Significance and Societal Importance of the Research Achievements

シデロフォアを介したケイ酸の取り込みが証明できれば新奇な発見であったが、予想に反してケイ酸の取り込みそのものにはシデロフォアが関与していないことが示された。一方、シデロフォアを合成できない遺伝子破壊株ではケイ酸取り込み量が顕著に減少したことから、取り込まれたケイ酸が重合してシリカが形成されるプロセスのどこかでシデロフォアが何らかの役割を果たしている可能性が示唆された。シデロフォアの未知の機能の発見につながることが期待される。