Collaborative Research: Phagotrophy and Nutrient Cycling in Mixotrophic Algae

一些淡水和海洋微藻摄取颗粒状食物的能力是一种显着的、具有生态意义的行为。尽管这种行为对浮游生物群落中的能量和营养物质的流动以及藻类的生存策略具有重要的影响，但相对较少的实验工作来建立对这种行为的限制(即最大摄食率)，检查对混合营养体的潜在生理益处(例如，获取C、N或P)，或者确定这种行为可能会给藻类带来的竞争优势。该项目将继续研究，以获得关于这一重要但普遍被忽视的自由生活原生生物群体的基线数据。未来工作的目标是继续在实验室培养中检查淡水和海洋混合营养藻类分离物，以了解它们消耗颗粒食物的能力。此外，还将对北大西洋不同营养状况的10个湖泊和几种环境进行调查，以了解混养藻类的存在和丰富程度，以及这些物种的细菌消耗率。项目资助将有助于生态学理论和知识库的建立，并有可能在水污染控制中应用。

The ability of some freshwater and marine microalgae to ingest particulate food is a remarkable and ecologically significant behavior. Despite the important implications of this behavior for the flow of energy and nutrients in plankton communities and for the survival strategies of the algae, there has been relatively little experimental work to establish constraints on this behavior (i.e., maximum ingestion rates), to examine the potential physiological benefits to the mixotroph (e.g., acquisition of C,N, or P), or to determine the competitive advantage that this behavior might confer on the alga. This project will continue research to obtain baseline data on this important, but generally overlooked, group of free-living protists. Goals for future work are to continue to examine freshwater and marine isolates of mixotrophic algae in laboratory culture for their ability to consume particulate food. In addition, a survey of 10 lakes of varying trophic status and several environments in the North Atlantic Ocean will be conducted for the presence and abundance of mixotroph algae, and the rates of bacterial consumption by these species. Project fundings will contribute to ecological theory and the knowledge base with potential application to water pollution control.