生物と非生物の成分が一体化する未来がきた!? 光合成ができるようになった“サイボーグバクテリア“が誕生
参考リンク：「Berkeley Lab」、ほか
参照元 ： TOCANA
How to Train Your Bacterium
Berkeley Lab Scientists Teach Bacterium a New Trick for Artificial Photosynthesis Science Shorts Lynn Yarris • JANUARY 1, 2016
Trainers of dogs, horses, and other animal performers take note: a bacterium named Moorella thermoacetica has been induced to perform only a single trick, but it’s a doozy. Berkeley Lab researchers are using M. thermoacetica to perform photosynthesis – despite being non-photosynthetic – and also to synthesize semiconductor nanoparticles in a hybrid artificial photosynthesis system for converting sunlight into valuable chemical products.
“We’ve demonstrated the first self-photosensitization of a non-photosynthetic bacterium, M. thermoacetica, with cadmium sulfide nanoparticles to produce acetic acid from carbon dioxide at efficiencies and yield that are comparable to or may even exceed the capabilities of natural photosynthesis,” says Peidong Yang, a chemist with Berkeley Lab’s Materials Sciences Division, who led this work.
“The bacteria/inorganic-semiconductor hybrid artificial photosynthesis system we’ve created is self-replicating through the bio-precipitation of cadmium sulfide nanoparticles, which serve as the light harvester to sustain cellular metabolism,” Yang says. “Demonstrating this cyborgian ability to self-augment the functionality of biological systems through inorganic chemistry opens up the integration of biotic and abiotic components for the next generation of advanced solar-to-chemical conversion technologies.”
Yang, who also holds appointments with UC Berkeley and the Kavli Energy NanoScience Institute (Kavli-ENSI) at Berkeley, is the corresponding author of a paper describing this research in Science. The paper is titled “Self-photosensitization of non-photosynthetic bacteria for solar-to-chemical production.” Co-authors are Kelsey Sakimoto and Andrew Barnabas Wong.
Photosynthesis is the process by which nature harvests sunlight and uses the solar energy to synthesize carbohydrates from carbon dioxide and water. Artificial versions of photosynthesis are being explored for the clean, green and sustainable production of chemical products now made from petroleum, primarily fuels and plastics. Yang and his research group have been at the forefront of developing artificial photosynthetic technologies that can realize the full potential of solar-to-chemical synthesis.
“In our latest study, we combined the highly efficient light harvesting of an inorganic semiconductor with the high specificity, low cost, and self-replication and self-repair of a biocatalyst,” Yang says. “By inducing the self-photosensitization of M. thermoacetica with cadmium sulfide nanoparticles, we enabled the photosynthesis of acetic acid from carbon dioxide over several days of light-dark cycles at relatively high quantum yields, demonstrating a self-replicating route toward solar-to-chemical carbon dioxide reduction.”
Cadmium sulfide is a well-studied semiconductor with a band structure and that is well-suited for photosynthesis. As both an “electrograph” (meaning it can undergo direct electron transfers from an electrode), and an “acetogen” (meaning it can direct nearly 90-percent of its photosynthetic products towards acetic acid), M. thermoacetica serves as the ideal model organism for demonstrating the capabilities of this hybrid artificial photosynthesis system.
“Our hybrid system combines the best of both worlds: the light-harvesting capabilities of semiconductors with the catalytic power of biology,” Yang says. “In this study, we’ve demonstrated not only that biomaterials can be of sufficient quality to carry out useful photochemistry, but that in some ways they may be even more advantageous in biological applications.”
This work was funded by the U.S. Department of Energy (DOE)’s Office of Science. The interface design part of the study was carried out the Molecular Foundry, a DOE Office Science User Facility hosted by Berkeley Lab.
Additional Information
For more about the research of Peidong Yang go here
# # #
Lawrence Berkeley National Laboratory addresses the world’s most urgent scientific challenges by advancing sustainable energy, protecting human health, creating new materials, and revealing the origin and fate of the universe. Founded in 1931, Berkeley Lab’s scientific expertise has been recognized with 13 Nobel prizes. The University of California manages Berkeley Lab for the U.S. Department of Energy’s Office of Science. For more, visit www.lbl.gov.
DOE’s Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit the Office of Science website at science.energy.gov/.
参照元 ： newscenter
2016.01.10
先日、NASAが公開した4Kカメラで撮影された太陽の姿をご覧になっただろうか。活発に燃焼している様子が鮮明に確認でき、地球にたくさんの光を降り注いでいる太陽の、あふれ出るエネルギーを感じさせてくれる。
この光エネルギーを利用する科学反応の一つが「光合成」であるが、今月1日に科学雑誌「Science」に掲載された論文によると、なんと、葉緑素を持たないバクテリアに手を加えて光合成をさせることに成功したのだという。
今回のシステムでは、低コストの生体触媒であるバクテリアで人工光合成をすることができた。また、自己複製機能を持つバクテリアを使用していることもあり、数日間にわたり、二酸化炭素から酢酸を効率よく作ることにも成功し、エコ社会に向けて一歩前進したとして、注目されている。
■光合成ができるようになったバクテリア
植物がすることでおなじみの光合成は、光エネルギーを化学エネルギーへと変換する化学反応である。今回、カリフォルニア大学バークレー校による研究では、光エネルギーを使用して二酸化炭素から酢酸を生成することに成功した。
その立役者となったのが、バクテリアと無機半導体である硫化カドミウムだ。今回実験で扱われたバクテリアは光合成をしない好熱性の酢酸産生菌である、ムーレラ・サーモアセチカ（Moorella thermoacetica）だが、半導体である硫化カドミウムのナノ分子の力を借りることで、光合成を成功。酢酸を生成したのだという。それも自然界の光合成と同等以上の効率であったとのことだ。
このバクテリアと無機半導体のハイブリッド光合成システムでは、バクテリアが、自身にまとわりついた半導体のナノ分子による集光作用を利用し、代謝を持続している。つまり無機化学の応用によって、この生物が本来持っていない光増感（光の取り込み）機能を拡張し、新たな結果を得たということだ。
硫化カドミウムは半導体として、光センサーの素材になるなど、光エレクトロニクスの分野でよく使用されている。サーモアセチカも、電子の移動を受けやすく、効率よく酢酸を産出する性質があり、人工光合成にうってつけのバクテリアであった。光を利用するのに長けた無機半導体と、生産性に富むバクテリア、それぞれの長所がよく生かされたシステムといえよう。
■人工光合成で太陽エネルギーの有効活用を
この研究を行ったのは、28歳にしてカリフォルニア大学バークレー校の教授に就任したという経歴を持つペイドン・ヤン教授らのグループである。ヤン教授は、光の粒子を利用する技術である「ナノフォトニクス」の研究家だ。
研究の成功を受けて、ヤン教授は、「さらに進化した次世代の人工光合成技術を目指し、生物と非生物が持つ成分の一体化を進めていける」と自信を深めている。
このように、人工光合成を低コスト・高効率で行えるようになれば、気候変動の原因とされている二酸化炭素対策や、再生可能エネルギーの開発を一度に実現することができる。すでに日本でも、酢酸から高効率でエタノールを人工光合成によって生成することに成功しており、近いうちに太陽エネルギーをフル活用したエコな社会が到来しそうだ。
参考リンク：「Berkeley Lab」、ほか
参照元 ： TOCANA
How to Train Your Bacterium
Berkeley Lab Scientists Teach Bacterium a New Trick for Artificial Photosynthesis Science Shorts Lynn Yarris • JANUARY 1, 2016
Trainers of dogs, horses, and other animal performers take note: a bacterium named Moorella thermoacetica has been induced to perform only a single trick, but it’s a doozy. Berkeley Lab researchers are using M. thermoacetica to perform photosynthesis – despite being non-photosynthetic – and also to synthesize semiconductor nanoparticles in a hybrid artificial photosynthesis system for converting sunlight into valuable chemical products.
“We’ve demonstrated the first self-photosensitization of a non-photosynthetic bacterium, M. thermoacetica, with cadmium sulfide nanoparticles to produce acetic acid from carbon dioxide at efficiencies and yield that are comparable to or may even exceed the capabilities of natural photosynthesis,” says Peidong Yang, a chemist with Berkeley Lab’s Materials Sciences Division, who led this work.
“The bacteria/inorganic-semiconductor hybrid artificial photosynthesis system we’ve created is self-replicating through the bio-precipitation of cadmium sulfide nanoparticles, which serve as the light harvester to sustain cellular metabolism,” Yang says. “Demonstrating this cyborgian ability to self-augment the functionality of biological systems through inorganic chemistry opens up the integration of biotic and abiotic components for the next generation of advanced solar-to-chemical conversion technologies.”
Yang, who also holds appointments with UC Berkeley and the Kavli Energy NanoScience Institute (Kavli-ENSI) at Berkeley, is the corresponding author of a paper describing this research in Science. The paper is titled “Self-photosensitization of non-photosynthetic bacteria for solar-to-chemical production.” Co-authors are Kelsey Sakimoto and Andrew Barnabas Wong.
Photosynthesis is the process by which nature harvests sunlight and uses the solar energy to synthesize carbohydrates from carbon dioxide and water. Artificial versions of photosynthesis are being explored for the clean, green and sustainable production of chemical products now made from petroleum, primarily fuels and plastics. Yang and his research group have been at the forefront of developing artificial photosynthetic technologies that can realize the full potential of solar-to-chemical synthesis.
“In our latest study, we combined the highly efficient light harvesting of an inorganic semiconductor with the high specificity, low cost, and self-replication and self-repair of a biocatalyst,” Yang says. “By inducing the self-photosensitization of M. thermoacetica with cadmium sulfide nanoparticles, we enabled the photosynthesis of acetic acid from carbon dioxide over several days of light-dark cycles at relatively high quantum yields, demonstrating a self-replicating route toward solar-to-chemical carbon dioxide reduction.”
Cadmium sulfide is a well-studied semiconductor with a band structure and that is well-suited for photosynthesis. As both an “electrograph” (meaning it can undergo direct electron transfers from an electrode), and an “acetogen” (meaning it can direct nearly 90-percent of its photosynthetic products towards acetic acid), M. thermoacetica serves as the ideal model organism for demonstrating the capabilities of this hybrid artificial photosynthesis system.
“Our hybrid system combines the best of both worlds: the light-harvesting capabilities of semiconductors with the catalytic power of biology,” Yang says. “In this study, we’ve demonstrated not only that biomaterials can be of sufficient quality to carry out useful photochemistry, but that in some ways they may be even more advantageous in biological applications.”
This work was funded by the U.S. Department of Energy (DOE)’s Office of Science. The interface design part of the study was carried out the Molecular Foundry, a DOE Office Science User Facility hosted by Berkeley Lab.
Additional Information
For more about the research of Peidong Yang go here
# # #
Lawrence Berkeley National Laboratory addresses the world’s most urgent scientific challenges by advancing sustainable energy, protecting human health, creating new materials, and revealing the origin and fate of the universe. Founded in 1931, Berkeley Lab’s scientific expertise has been recognized with 13 Nobel prizes. The University of California manages Berkeley Lab for the U.S. Department of Energy’s Office of Science. For more, visit www.lbl.gov.
DOE’s Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit the Office of Science website at science.energy.gov/.
参照元 ： newscenter
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