Scientists have recently learned how to use
light to control specific groups of neurons to better understand the operation of the brain, a development that has transformed areas of neuroscience.
“這項技術使我們能夠以前所未有的方式控制細胞的新陳代謝,”聯合首席研究員JoséL. Avalos說,他是化學和生物工程的助理教授,普林斯頓的安德林格能源和環境中心。 “它打開了用光控制新陳代謝的大門。”
"This technique allows us to control the metabolism of cells in an unprecedented way," said co-lead researcher José L. Avalos, an assistant professor of chemical and biological engineering and Princeton's Andlinger Center for Energy and the Environment. "It opens the door to controlling metabolism with light."
Yeast has been used for centuries to make bread, wine and beer. Through fermentation, yeast cells transform sugar into chemicals that make bread rise and turn grape juice into wine. Using their new technique, the Princeton researchers have now used fermentation and genetically-engineered yeast to produce other chemicals including lactic acid, used in food production and bioplastics, and isobutanol, a commodity chemical and an advanced biofuel.
Light played a key role in the experiment because it allowed the researchers to switch on genes that they had added to the yeast cells. These particular genes are sensitive to light, which can trigger or suppress their activity. In one case, turning on and off a blue light caused the special yeast to alternate between producing ethanol, a product of normal fermentation, and isobutanol, a chemical that normally would kill yeast at sufficiently high concentration.
光在實驗中發揮了關鍵作用,因為它允許研究人員轉換他們添加到酵母細胞中的基因。 這些特定的基因對光敏感,可以觸發或抑制其活動。 在一種情況下,開啟和關閉藍色光使得特殊酵母在生產正常發酵產物乙醇和異丁醇之間交替,異丁醇通常會以足夠高的濃度殺死酵母。
生產這些化學品的成就是顯著的,但研究人員對光在代謝研究中發揮更廣泛作用的發展很感興趣。
The achievement of producing these chemicals was significant, but the researchers were intrigued by the development of light's broader role in metabolic research.
"It provides a new tool with the ability to do sophisticated experiments to determine how metabolism works and how to engineer it," Avalos said.
In a March 21 paper in the journal Nature, the researchers reported that they used light to increase yeast's production of the chemical isobutanol as much as 5times higher than previously reported levels in peer-reviewed studies The researchers used a genetically modified strain of the yeast Saccharomyces cerevisiae in the experiments.
Isobutanol is an alcohol used in products such as lubricants, gasoline and jet fuel replacements, and plastics. With good compatibility with gasoline infrastructure, isobutanol has properties that could make it a direct substitute for gas as a vehicle fuel. However, most attempts to create isobutanol biofuel have run into difficulties involving cost or scaling production to an industrial level. Although natural yeast fermentation produces isobutanol, it does so in miniscule amounts. Instead, yeast makes high volumes of ethanol (the alcohol in beer and wine) and carbon dioxide (a gas that makes bread rise).
“它提供了一個新的工具,能夠進行複雜的實驗,以確定新陳代謝是如何工作的,以及如何設計它,”Avalos說。