LEXEN: Protistan Biodiversity in Antarctic Marine Ecosystems: Molecular Biological and Traditional Approaches

* 卡隆酒店9714299 极端环境中微生物生物多样性的分析是困难的，因为传统的多样性检查方法往往是无效的评估这些社区内的物种丰富度。由于在样品收集和处理期间难以重建和维持相关的环境特征，因此出现了其他困难。本研究主要研究南极罗斯海海冰、沉积物和海洋环境中的原生生物组合（藻类和原生动物）。 在自然群落中识别原生生物物种传统上需要直接的显微镜分析以及评估生物多样性的富集和培养技术。因此，这些组合的多样性的测定容易受到偏见的采样，富集和文化，以及由于样品保存和浓缩显微镜的选择性损失的结果。该项目的目标是：（1）开发和应用分子生物学方法，评估海水、海冰和沉积物环境中小型原生生物（小于100微米的藻类和原生动物）的物种多样性;（2）获取有关温度条件下培养原生动物的生长率、摄食率和生长效率的基线生理信息。分子生物学研究将涉及使用PCR为基础的协议，检查小亚基核糖体RNA基因（srDNA）的多样性。开发的方法和技术将适用于任何其他水体或沉积物，并将提供一种手段，以检查现存的文化收藏的原生生物文化的代表性。 ***

*** Caron 9714299 The analysis of microbial biodiversity of extreme environments is difficult because traditional methods for examining diversity are often ineffective for assessing species richness within these communities. Additional difficulties arise due to the difficulties of recreating and maintaining pertinent environmental features during sample collection and procession. This study focuses on the protistan assemblages (algae and protozoa) in the sea ice, sediment and ocean environments of the Ross Sea, Antarctica. The identification of protistan species in natural assemblages traditionally has entailed direct microscopical analyses as well as enrichment and culture techniques for assessing biodiversity. Determination of diversity for these assemblages in therefore susceptible to biases as a consequence of sampling, enrichment and culture, as well as selective losses due to sample preservation and concentration for microscopy. The goals of this project are: (1) to develop and apply molecular biological approaches to assess species diversity of small protists (algae and protozoa smaller than 100 micrometers) in ocean water, sea ice and sediment environments and (2) to obtain baseline physiological information on the growth rates, feeding rates and growth efficiencies of cultured protozoa under pertinent temperature regimes. Molecular biological studies will involve the use of PCR-based protocols to examine small subunit ribosomal RNA gene (srDNA) diversity. Approaches and techniques developed will be applicable to any other water body or sediment and would provide a means to examine the representativeness of protistan cultures in extant culture collections. ***