Investigation of biovolatilization mechanism in rare metal metabolizing bacterium and development of biovolatile compounds recovery

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K06876
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Biofunction/Bioprocess
• Research Institution: Shibaura Institute of Technology
• Principal Investigator: Yamashita Mitsuo 芝浦工業大学, 工学部, 教授 (40220347)
• Research Collaborator: Horiike Takumi ; Otsuka Osamu ; Fukazawa Fumito ; Kotake Fumiya ; Udagawa Kento
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: レアメタル / セレン / 生物気化 / メカニズム / 回収

Outline of Final Research Achievements

Selenate reducing bacterium, Pseudomonas stutzeri strain NT-I reduce selenate, selenite, and biogenic elemental selenium into volatile selenium (Se), dimethyldiselenide (DMDSe). DMDSe was recovered at about 39% in nitric acid from waste water containing Se using strain NT-I. The biogenic elemental selenium was recycled at 99.7% purity from Se compounds in nitric acid by a sequence of reaction of neutralization, oxidation and reduction. The recombinant E. coli DH5a (lac-ME-His) was constructed harbouring DMDSe synthesis gene under lactose promoter. The recombinant E. coli DH5a (lac-ME-His) reduced biogenic elemental selenium and synthesized volatile DMDSe as same level as strain NT-I. Taken together, we succeeded in development of selenium recovery technology including recombinant DMDSe synthesis gene from waste water.

Free Research Field

工学

Academic Significance and Societal Importance of the Research Achievements

太陽電池に使用されているレアメタルの1種類であるセレンに注目し、セレン還元細菌Pseudomonas stutzeri strain NT-Iの気化能（セレンバイオボラタリゼーション）を活用してセレンを含む廃水から高純度の元素態セレンを精錬し、浄化回収資源化技術開発に成功した。生物由来の特異なバイオボラタリゼーションを利用したレアメタル浄化回収技術は廃水や廃棄物から有価資源を回収するという特色のある手法であり、「循環型社会」形成の一助となると期待できる。