EAGER: Alternative defensive mechanisms of autotrophs from harmful reactive oxygen species

蓝细菌（也称为蓝绿藻）能够在各种环境中茁壮成长。生态干扰往往有利于蓝细菌的生长，因为它们能够适应环境的快速变化。有时，环境条件的变化会导致蓝藻菌群密集（藻华），它们也可能产生高浓度的毒素（蓝藻毒素），杀死鱼类，对人类构成危害。这个早期概念探索性研究资助（EAGER）项目的目标是测试蓝藻毒素是否具有重要的替代生物化学和生态功能，即通过去除过氧化氢来保护蓝藻。如果这被证明是真的，它将改变我们对淡水湖结构和功能的理解。 EAGER项目的结果也可能导致对有害蓝藻水华的更有效和更经济的管理。有害藻类大量繁殖期间释放的蓝藻毒素会对健康构成威胁，需要数百万美元来净化淡水供应。该项目还将包括为本科生和研究生提供研究培训机会，努力扩大对科学的参与。最重要的环境梯度之一是由氧气形成的，它的可用性对生命的分布模式至关重要。蓝细菌是第一个建立产生氧气的光合作用的谱系。蓝藻光合作用捕获太阳能，但它有产生活性氧的风险，如过氧化氢。能够处理细胞内活性氧分子的细胞过程的发展是蓝藻光合作用进化的关键。这个EAGER项目将测试一个有趣的假设，为什么蓝藻产生蓝藻毒素，他们的功能是隔离过氧化氢，或以其他方式将其转化为非反应形式。在这个项目中，有毒和无毒的蓝藻菌株将比较相对于过氧化氢的生产。一种新的过氧化氢微传感器将被用来检查过氧化氢在薄表面湖水中的微尺度分布，以确定是否（与假设一致）它与产毒蓝藻的丰度成反比。最后，研究将确定是否可以通过添加α-酮酸来抑制细胞产生的任何过氧化氢来提高分离和培养新型蓝藻的能力。

Cyanobacteria (also known as blue-green algae) are capable of thriving in a variety of environments. Ecological disturbances often favor growth of cyanobacteria because of their capability to adapt to rapid changes in the environment. Sometimes changes in environmental conditions can result in dense populations of cyanobacteria, (algal bloom) and they may also produce high concentrations of toxins (cyanotoxins) that kill fish and are a hazard to humans. The goal of this EArly-concept Grant for Exploratory Research (EAGER) project is to test whether cyanotoxins have an important alternative biochemical and ecological function, namely, to protect the cyanobacteria by removing hydrogen peroxide. If this proves to be true, it would transform our understanding of the structure and function of freshwater lakes. The results from this EAGER project may also lead to more effective and economical management of harmful cyanobacerial blooms. Cyanotoxins released during harmful algal blooms can pose health risks, and require millions of dollars to decontaminate freshwater supplies. The project will also include research training opportunities for undergraduate and graduate students, with efforts to broaden participation in science.One of the most important environmental gradients is formed by oxygen, and its availability is fundamental to the distribution patterns of life. Cyanobacteria were the first lineage to establish oxygen-producing photosynthesis. Cyanobacterial photosynthesis captures solar energy, but it comes at the risk of producing reactive oxygen species such as hydrogen peroxide. The development of a cellular process capable of handling intracellular reactive oxygen molecules was key to the evolution of cyanobacterial photosynthesis. This EAGER project will test an intriguing hypothesis about why cyanobacteria produce cyanotoxins, that they function to sequester hydrogen peroxide, or otherwise convert it to a non-reactive form. In this project, toxic and non-toxic cyanobacterial strains will be compared with respect to hydrogen peroxide production. A new hydrogen peroxide microsensor will be used to examine the microscale distribution of hydrogen peroxide in thin surface lake water to determine whether (consistent with the hypothesis) it is inversely proportional with the abundance of toxin-producing cyanobacteria. Finally, studies will determine whether the ability to isolate and grow novel cyanobacteria in culture can be improved by adding alpha-keto acids to scavenge any hydrogen peroxide produced by cells.