The Metabolic Response of Coastal Bacteria to Mortality-Derived Phytoplankton Dissolved Organic Matter

微生物通过交换溶解在周围沃茨中的化学物质相互作用。几十年的生物化学研究已经确定了微生物生长和健康所需的一小套化学物质。这个有限的套件现在正在扩展与新的分析工具的基础上质谱。在这个项目中，重点将放在微生物死亡过程中释放的化学物质上，特别关注病毒感染后的爆裂细胞和原生动物（单细胞生物）啃食后的细胞残余物。这些化学物质不是由它们的生产者故意释放的，但它们仍然可以影响附近细菌的生长和健康，进而影响细菌将这些分子转化为二氧化碳的能力。拟议中的对褐潮藻死亡期间释放的化学物质的类型和反应性的比较将有助于改进沿海海洋碳循环的模型。两名研究生将直接得到该项目的支持。 提议者计划教两门课，一门是质谱学课程，另一门是环境代谢组学课程。 预计作为代谢组学课程发展的一部分，代谢组学数据培训将成为课程的一部分。 微生物聚生体对周围环境的化学变化非常敏感，微生物群落的多样性随着可用生长基质和营养物质的组成而演变。因此，微生物之间通过溶解有机物（DOM）环境的相互作用是全球碳循环的核心，因此值得进行重要的研究和调查。该项目的重点是通过病毒裂解或原生动物放牧微生物死亡期间释放的分子。使用新的质谱为基础的工具，该项目链接的溶解有机物的组成，从微生物死亡与异养细菌的能力，使这些底物的微生物。代谢参数和碳转化率将被确定为DOM源的函数，以评估DOM类型对微生物生理和碳周转的影响。模式生物的实验室结果将与模式生物主导水生群落的实地环境进行比较。该项目将产生一系列分子，可在未来的实验中用作微生物死亡率的标志物，并将提供病毒裂解物和食草动物来源的DOM的反应性之间的定量比较。这些结果将支持微生物网络及其对全球碳循环的影响的改进参数化。

Microbes interact with one another through the exchange of chemicals dissolved in their surrounding waters. Decades of biochemical research have identified a small suite of chemicals that are required by microbes for growth and well-being. This limited suite is now being expanded with novel analytical tools based on mass spectrometry. In this project, the focus will be on chemicals that are released during the death of microbes, with particular attention paid to burst cells after viral infections and to the remnants of cells after grazing by protozoa (single celled organisms). These chemicals are not intentionally released by their producers, but they can still affect the growth and well-being of nearby bacteria and in turn the bacteria's ability to convert these molecules to carbon dioxide. The proposed comparison of the types and reactivities of chemicals released during the death of a brown tide alga will help improve models of carbon cycling in the coastal ocean. Two graduate students will be supported directly by this project. The proponent plans to teach two classes, one a mass spectrometry course, the other an environmental metabolomics course. It is anticipated that as part of the evolution of the metabolomics course, data-training for metabolomics would become part of the course. Microbial consortia are exquisitely sensitive to chemical changes in their surroundings and the diversity of microbial communities evolves with the composition of available growth substrates and nutrients. Thus, interactions between microbes, through the milieu of dissolved organic matter (DOM), lie at the heart of the global carbon cycle and thus merit significant study and investigation. This project focuses on the molecules that are released during microbial mortality through viral lysis or protozoan grazing. Using novel mass spectrometry-based tools, this project links the composition of dissolved organic matter derived from microbial mortality with the ability of heterotrophic bacteria to remineralize these substrates. Metabolic parameters and carbon transformation rates will be determined as a function of DOM source to assess the impact of DOM type on microbial physiology and carbon turnover. Laboratory results from model organisms will be compared to field settings where the model organisms dominate planktonic communities. The project will generate a suite of molecules that can be used in future experiments as markers of microbial mortality and will provide quantitative comparisons between the reactivity of viral lysate and grazer-derived DOM. These results will support improved parameterizations of microbial networks and their impact on the global carbon cycle.