Bacterivorous Ciliates in Marine Food Webs: Lipid Chemistry and Copepod Nutrition

嗜菌纤毛虫是浮游食物网的重要组成部分。它们可以消耗大量的细菌产物，并将低必需脂质的物质（细菌生物量和碎屑）转化为富含脂质的纤毛虫生物量。消费者如何从这些纤毛虫中获得营养，它们在纤毛虫碳的生化转化中起什么作用？为了研究纤毛虫脂质的性质及其在海洋食物网中的命运和重要性，Harvey博士和McManus博士将：识别和量化纤毛虫脂质，特别是那些可能在营养研究中作为群体特异性生物标志物的纤毛虫脂质。-检查纤毛虫饮食中的脂质来源，并跟踪纤毛虫如何吸收和改变饮食中的脂质。-测量纤毛虫脂的主要消耗者之一桡足类对纤毛虫脂的同化和转化。本项目将生化测量与饲养实验相结合。对许多纤毛虫物种进行详细的脂质分析，将首先为他们已经观察到的独特化合物的普遍性提供额外的数据。他们将详细测量饮食对几种具有代表性的细菌纤毛虫的脂质含量和分布的作用。最后，他们将进行深入的摄食实验，跟踪放牧桡足类动物对纤毛虫脂质的掺入和转化。这些结果将提供大量新的信息，说明细菌纤毛虫在海洋食物网中的作用，特别是它们在桡足动物营养中的重要性。

Bacterivorous ciliates are an important component of planktonic food webs. They can consume a large proportion of bacterial production, and convert material that is low in essential lipids (bacterial biomass and detritus) into lipid-rich ciliate biomass. How do consumers benefit nutritionally from these ciliates, and what role do they play in the biochemical transformation of ciliate carbon? To investigate the nature of ciliate lipids and their fate and importance in the marine food web Dr. Harvey and McManus will: - identify and quantify ciliate lipids, especially ones that may be useful as group-specific biomarkers in trophic studies. - examine sources of lipids in the ciliate diet and follow how ciliates assimilate and modify dietary lipids. - measure the assimilation and transformation of ciliate lipids by one of their principal consumers, copepods. This project combines biochemical measurements with feeding experiments. Detailed lipid analysis of a number of ciliate species will first provide additional data on the ubiquity of the unique compounds they have already observed. They will measure in detail the role of diet on lipid content and distribution of several representative bacterivorous ciliates. Finally, they will conduct in-depth feeding experiments to follow the incorporation and transformation of ciliate lipids by grazing copepods. These results will provide substantial new information on the role of bacterivorous ciliates in the marine food web, especially their importance in copepod nutrition.