Spatial Scales of Genetic and Phenotypic Diversity Among Streptomycetes in Native Soils

9977907 Kinkel，L.Samac，D.这个微生物观测站将提供关于在雪松溪自然历史区本地土壤中出现的链霉菌细菌遗传和表型多样性的基本信息，雪松溪自然历史区是明尼苏达州中部森林-草原交界处的一个长期生态研究地点。特别是，这项工作将为深入了解这些群落中菌株间抗生素抑制、耐药性和诱导的动态，以及分析这些表型特征的空间、时间和遗传背景提供重要的见解。还将对土壤氮素处理对群落的影响进行评价。本研究的具体目的是：1.评价氮素输入对土壤中链霉菌群落的影响。为此，将通过对比在两种不同氮素输入水平下保持的土壤中链霉菌的种群密度；对比在两种氮素水平下保持的土壤中链霉菌群落的多样性，特别是关注遗传多样性和抗生素抑制和耐药性方面的多样性。2.在一系列空间尺度上量化链霉菌的遗传多样性和表型多样性；量化链霉菌在单个土芯、同一地块的单独岩心和不同地块的遗传多样性；量化各个土芯、同一地块的单独岩心和不同地块的链霉菌之间抑菌谱的多样性；以及量化各个土芯、同一地块的单独岩心或不同地块的链霉菌之间的抗药性多样性。3.确定空间起源、当地群落的种群密度和遗传亲缘关系对链霉菌抑制、抗性和抗生素诱导潜力的影响。这将通过确定来自同一地点(土核)、相同地块或相同氮素处理的菌株是否比来自不同土芯、不同地块或不同氮素处理的菌株更有可能抑制、抵抗抑制或诱导抗生素产生来实现；确定基因关系密切的菌株是否比亲缘关系较远的菌株更有可能相互抑制、抵抗彼此的抑制或诱导彼此产生抗生素；以及确定来自土壤中高密度地点的分离物是否比来自低密度地点的分离物更有可能抑制其他分离物、抵抗他人的抑制或诱导其他人产生抗生素。这些信息将为了解抗生素相互作用对土壤中的进化和微生物种群动态的潜在意义提供基本的见解。

9977907Kinkel, L.Samac, D.This Microbial Observatory will provide fundamental information on the genetic and phenotypic diversity among Streptomycetes bacteria occurring in native soils at Cedar Creek Natural History Area, a Long Term Ecological Research site at the forest-prairie interface in central Minnesota. In particular, this work will provide significant insight into the dynamics of interisolate antibiotic inhibition, resistance, and induction within these communities, as well as a spatial, temporal, and genetic context for analyzing these phenotypic characters. The influence of soil nitrogen treatment on the community will also be evaluated here. The specific objectives of the research are to: 1. Evaluate the influence of nitrogen inputs on the Streptomycete community in soil. This will be done by contrasting the population densities of Streptomycetes in soils maintained at two different nitrogen input levels; contrasting the diversity of Streptomycete communities in soils maintained at the two nitrogen levels, specifically focusing on genetic diversity and diversity in antibiotic inhibition and resistance. 2. Quantify the genetic and phenotypic diversity in Streptomycetes across a range of spatial scales; quantifying genetic diversity among Streptomycetes in individual soil cores, in separate cores from the same plot, and from different plots; quantifying diversity in inhibition profiles among Streptomycetes in individual soil cores, in separate cores from the same plot, and from different plots; and quantifying diversity in resistance profiles among Streptomycetes in individual soil cores, in separate cores from the same plot, or from different plots. 3. Determine the influence of spatial origin, population density of the local community, and genetic relatedness on the potential for inhibition, resistance to inhibition, and antibiotic induction among Streptomycetes. This will by done by determining whether isolates from the same location (soil core), same plot, or same nitrogen treatment are more or less likely to inhibit, to resist inhibition by, or to induce antibiotic production than isolates from different soil cores, different plots, or different nitrogen treatments; determining whether isolates that are genetically closely related are more or less likely to inhibit one another, to resist inhibition by one another, or to induce antibiotic production in one another than isolates that are more distantly related; and determining whether isolates from high density locations in soil are more or less likely to inhibit other isolates, resist inhibition by others, or induce antibiotic production in others than isolates from low density locations. This information will provide fundamental insight into the potential significance of antibiotic interactions for evolution and microbial population dynamics in soils.