Regulation of Genes Required for Nitrogen Fixation in Anabaena Heterocysts

该项目的目标是了解某些类型的细菌如何能够为自己提供氮肥，这是所有生物体生长所必需的。该项目将在细胞和分子水平上确定这些被称为蓝藻的细菌是如何产生细胞和酶的，这些细胞和酶可以“固定”空气中的氮，从而产生可以进入细胞代谢的化合物。蓝藻是绿色的，和植物一样通过光合作用从阳光中获取能量。像藻类一样，蓝藻是重要的初级生产者，在许多环境中，尤其是海洋中，它们是其他生物的食物，它们从大气中去除二氧化碳，从而减少全球变暖的影响。固氮蓝藻在自然环境中提供生物可利用的氮，在世界一些地区被用作水稻种植的氮肥。最近，人们对利用蓝藻和藻类从阳光中获取能量来生产生物质、生物柴油和乙醇等生物燃料以及氢气产生了极大的兴趣。该项目将使用成熟的模式生物水藻来确定被称为异囊的特殊细胞如何产生固氮所需的酶。该项目将使用遗传学、分子生物学和生物化学的方法来研究这些过程。该项目有望揭示这一庞大而重要的微生物群体的遗传调控和基因表达的新机制。了解控制固氮基因的机制将增强我们对基本微生物生物学、遗传学和新陈代谢的认识，并将提供可应用于工业碳捕获和生物燃料生产的知识。在这个项目的过程中，本科生、研究生和博士后将接受最先进的研究方法的培训。这项研究还将产生对学术界和工业界的其他研究人员有用的材料和方法，该项目的长期目标将通过提供与自然生态系统、农业、全球变暖和生物燃料有关的基本知识来造福社会。

The goals of this project are to understand how certain types of bacteria are capable of supplying themselves with nitrogen fertilizer, which is required for the growth of all organisms. The project will determine at the cellular and molecular level, how these bacteria, called cyanobacteria, produce the cells and enzymes that "fix" nitrogen from the air to produce compounds that can enter cell metabolism. Cyanobacteria are green in color and obtain energy from sunlight with photosynthesis similarly to plants. Like algae, cyanobacteria are important primary producers, which are food for other organisms, in many environments, especially the oceans, and they remove carbon dioxide from the atmosphere, which reduces effects of global warming. Nitrogen-fixing cyanobacteria provide biologically available nitrogen in natural environments and are used as nitrogen fertilizer for rice cultivation in some parts of the world. Recently, there has been enormous interest in using cyanobacteria and algae to capture energy from sunlight to produce biomass, biofuels such as biodiesel and ethanol, and hydrogen gas. This project will use the well-established model organism Anabaena to determine how specialized cells called heterocysts produce the enzymes required for nitrogen fixation. The project will use methods of genetics, molecular biology, and biochemistry to study these processes. This project is expected to reveal new mechanisms of genetic regulation and gene expression in this large and important group of microorganisms. Understanding the mechanisms that control nitrogen-fixation genes will enhance our knowledge of basic microbial biology, genetics, and metabolism, and will provide knowledge that can be applied to industrial carbon capture and biofuel production. During the course of this project, undergraduate, graduate, and postdoctoral students will receive training in state-of-the-art research methods. The research will also produce materials and methods that will be useful to other researchers in both academia and industry, and the long-term goals of this project will benefit society by providing basic knowledge related to natural ecosystems, agriculture, global warming, and biofuels.