Bacterial Diversity Patterns along Gradients of Primary Productivity in Freshwater Ecosystems

“淡水生态系统中沿着初级生产力梯度的细菌多样性模式”生命最引人注目的方面之一是它在地球上的分布不均匀。 有些地区（如低地地区和热带地区）有高度多样性的植物和动物;其他地区（如山顶和极地地区）似乎几乎没有生命。 可利用的环境能量的差异是造成这种格局的主要原因。 然而，目前还不清楚地球上最大的生物群体（微生物）的多样性是否也随可用能量而变化。 初步观察表明，在水生生态系统中的细菌多样性和可利用的环境能量之间可能存在的关系。 本项目的目标是验证这些初步观察结果。 更具体地说，细菌多样性将在不同的可用能量的池塘中进行估计。 由于环境样本中的大多数细菌不能在实验室中生长，因此将使用不需要在实验室条件下生长细菌的分子技术来评估细菌多样性。 细菌多样性将估计提取细菌核糖体基因从池塘样品和测序这些基因。 细菌分类多样性将从这些基因的序列多样性估计。 单个细菌功能组内的多样性也将通过从池塘样品中提取和测序amoA基因来估计。 amoA基因是氧化氨的细菌所特有的。 这些细菌的多样性将从这些基因的序列多样性来估计。 这项研究将是第一次全面的尝试，以衡量细菌多样性沿着梯度的可用能量。 它有可能产生关于微生物分布的基本新知识，并可能影响环境管理和寻找新药物等不同领域。

"Bacterial diversity patterns along gradients of primary productivity in freshwater ecosystems" One of the most striking aspects of life is that it is distributed unevenly across the Earth. Some regions (such as lowland areas and the tropics) have a high diversity of plant and animal life; others (such as mountain tops and the polar regions) appear nearly devoid of life. Differences in available environmental energy are a major cause of such patterns. However, it is unknown whether the diversity of the largest group of organisms on Earth (microorganisms) also varies with available energy. Preliminary observations suggest that a relationship may exist between bacterial diversity and available environmental energy in aquatic ecosystems. The goal of this project is to verify these preliminary observations. More specifically, bacterial diversity will be estimated in ponds that differ in available energy. Because most bacteria from environmental samples cannot be grown in the laboratory, bacterial diversity will be assessed using molecular techniques that do not require bacterial growth under laboratory conditions. Bacterial diversity will be estimated by extracting bacterial ribosomal genes from pond samples and sequencing these genes. Bacterial taxonomic diversity will be estimated from the sequence diversity of these genes. The diversity within a single bacterial functional group also will be estimated by extracting and sequencing amoA genes from pond samples. The amoA gene is unique to bacteria that oxidize ammonia. The diversity of these bacteria will be estimated from the sequence diversity of these genes. This study will be the first comprehensive attempt to measure bacterial diversity along a gradient of available energy. It has the potential to generate fundamental new knowledge concerning the distribution of microorganisms and could impact fields as diverse as environmental management and the search for novel pharmaceuticals.