DISSERTATION RESEARCH: Elucidating stoichiometric and biogeochemical consequences of soil heterotrophic bacterial life history strategies

对微生物群落结构和生态系统功能之间关系的机制性理解是将微生物生态学从基于观察的科学转变为假设驱动的科学的关键。该项目将植物和动物的生活史策略框架适应于微生物生态学，以实现土壤细菌对环境条件变化的反应的机制，假设驱动的检查。通过研究土壤细菌的单个物种，并采取整体有机体的方法，该项目研究了生长速率和效率之间的权衡对不同土壤细菌的营养需求和生长的生物地球化学后果的作用。这种整体的方法允许从性状和基因组分配的模式中产生概括，有效地定义细菌的生活史策略。生活史策略允许在个体生物和细菌群落水平上产生假设。土壤细菌负责陆地环境中大部分固定C的加工和再循环。通过定义生活史策略，该项目加深了对环境条件变化对土壤微生物群落动态和影响其他生态系统过程的反馈的影响的理解。在这个项目中发现的概括不仅适用于生态系统生态学领域，而且适用于任何理解微生物群落功能的机械基础的地方，包括生物修复，合成生态学和人类健康微生物学。

Mechanistic understanding of the relationship between microbial community structure and ecosystem function is the key to moving microbial ecology from an observation-based to a hypothesis-driven science. This project adapts a life history strategy framework developed in plants and animals to microbial ecology to enable mechanistic, hypothesis-driven examination of soil bacterial response to changes in environmental conditions. By examining individual species of soil bacteria and taking a whole-organism approach, this project investigates the role of tradeoffs between growth rate and efficiency on the nutrient requirements and biogeochemical consequences of growth across a diverse range of soil bacteria. This holistic approach allows generalizations to emerge from patterns in traits and genome allocation effectively defining bacterial life history strategies. Life history strategies allow generation of hypotheses at both the individual organism and bacterial community levels.Soil bacteria are responsible for the processing and recycling of the majority of C fixed in terrestrial environments. By defining life history strategies this project deepens understanding of the effects of changes in environmental conditions on soil microbial community dynamics and feedbacks affecting other ecosystem processes. The generalizations discovered in this project promise to be applicable not only in the field of ecosystem ecology, but anywhere understanding the mechanistic basis of microbial community function is important including bioremediation, synthetic ecology, and human health microbiology.