In situ Analyses of the Distributions and Phylogeny of Cultivatable and Non-cultivatable Planctomycetales Using Phylogenetic Group-Specific RNA Probes

微生物生态系统中大多数可直接计数的细菌不能用传统的微生物学技术鉴定或培养，因此培养的细菌可能不能代表实际的微生物多样性。plantomycetes是由16S核糖体RNA定义的十大真细菌分裂之一。这组不寻常的核糖体RNA特征使它们非常适合使用核糖体RNA探针技术进行微生物生态学研究。近年来，系统发育类群特异性DNA探针的发展使研究植物在自然生境中的分布和多样性成为可能，而不受培养要求的影响。两种plantomycetales探针（PL1R和PL2R）和一种“通用”rRNA探针将用于测量从混合微生物群体中提取的DNA中plantomycetales核糖体RNA基因的比例。荧光标记的DNA探针将用于测量plantomycetales附着在接触载玻片上的微生物种群的贡献。系统发育群体特异性基因扩增引物将用于通过克隆和测序rRNA基因来鉴定plantomycetale群体的特定成分。这些结果将与已知plananctomycetale序列的数据库进行比较，以确定以前未栽培的物种是否存在于种群中。

The majority of directly countable bacteria in microbial ecosystems cannot be identified or cultivated using traditional microbiological techniques thus, cultured bacteria may not be representative of actual microbial diversity. The Planctomycetales are one of the ten major eubacterial divisions defined by 16S ribosomal RNA. the unusual ribosomal RNA signatures of this group make them exceptionally well-suited for microbial ecology studies using ribosomal RNA probe technologies. The recent development of phylogenetic group-specific DNA probes has made it possible to study the distribution and diversity of the Planctomycetales in natural habitats without the biases of cultivation requirements. Two probes for the Planctomycetales (PL1R and PL2R) and a "universal" rRNA probe will be used to measure the fraction of Planctomycetales ribosomal RNA genes in DNA extracted from mixed microbial populations. Flourescently labeled DNA probes will be used to measure the contribution of the Planctomycetales to attached microbial populations adhering to contact slides. Phylogenetic group-specific gene amplification primers will be used to identify particular constituents of the Planctomycetales population by the cloning and sequencing of rRNA genes. These results will be compared to a data base of known Planctomycetales sequences to determine whether previously uncultivated species are present in the population.