Improvement of production of useful substances and crops by modifying sulfur metabolism of microorganisms and plants

2019 Fiscal Year Final Research Report

• Project/Area Number: 15KT0028
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Multi-year Fund
• Section: 特設分野
• Research Field: Food Cycle Research
• Research Institution: Tokyo University of Agriculture and Technology
• Principal Investigator: OHTSU NAOKO 東京農工大学, (連合)農学研究科(研究院), 教授 (40513437)
• Co-Investigator(Kenkyū-buntansha): 河野 祐介 筑波大学, 生命環境系, 助教 (40558029) ; 大津 厳生 筑波大学, 生命環境系, 准教授 (60395655) ; 丸山 明子 九州大学, 農学研究院, 准教授 (70342855)
• Project Period (FY): 2015-07-10 – 2020-03-31
• Keywords: 硫黄源 / 植物 / 微生物 / チオ硫酸 / システイン

Outline of Final Research Achievements

In the microorganism, a novel metabolic pathway for synthesizing cysteine and homocysteine from thiosulfate through rhodanese (sulfur transferase) was identified. A novel metabolic pathway utilizing thiosulfate has been applied to cysteine and ergocysteine production. We also found that the Hmt2-deficient strain of fission yeast cannot grow on a single sulfur source of sulfate. The available inorganic and organic sulfur sources were clarified using Arabidopsis. It was suggested that the inorganic sulfur source is absorbed by the sulfate transporters. In Arabidopsis thaliana and rice, reduced sulfur increased in the body using thiosulfate as a sulfur source, compared with sulfate. Together with the results of gene expression changes, we proposed a thiosulfate metabolic pathway in plants.

Free Research Field

植物栄養学

Academic Significance and Societal Importance of the Research Achievements

微生物においては、新たなチオ硫酸代謝経路を同定し、システインやエルゴシステイン生産に応用し、工業的なレベルの生産を達成できることまで確認した。またサルファーインデックス法を改良し、特許化し、社会実装を果たした。植物については、これまで未知であった硫酸塩以外の硫黄源を示し、チオ硫酸については代謝経路を示すことができた。