Assessment of the functional diversity of soil microbial communities in the German Biodiversity Exploratories by metagenomics

土壤微生物的多样性超过了其他环境，分析土壤微生物群落的多样性仍然是一个巨大的挑战。该项目是一项倡议的一部分，该倡议旨在探索土壤微生物在植被类型和土地利用强度方面的多样性，并通过采用宏基因组技术将其与不同尺度的生态梯度联系起来。这项研究是在三个德国生物多样性探索中心的框架下在草地和森林采样点进行的。将开发一种方法，并作为范例应用，以应对土壤中巨大的微生物多样性。该方法是基于识别和选择（过滤）目标，如生物群体或编码关键微生物功能的基因（这里是纤维素分解酶和脂肪分解酶），然后分析它们在不同时空尺度上与植被类型和利用强度的关系。该策略依赖于三个步骤：(i)从覆盖不同植被类型和使用强度的土壤样品中提取微生物DNA，构建复杂的宏基因组文库。（ii）通过快照测序对示范性生物和功能群体的文库进行比较筛选，以确定（过滤）在采样地块之间显示差异和呈现不同概况的目标。（三）构建和使用微阵列和引物，监测探索区内过滤后的目标与植被类型、利用强度和时空变化的关系。

The microbial diversity in soils exceeds that of other environments and analyzing the diversity of soil microbial communities is still a great challenge. The project is part of an initiative that aims to explore the diversity of soil microorganisms with respect to vegetation type and land use intensity and relate it to ecological gradients at different scales by employing metagenomic technologies. The research is carried out at grassland and forest sampling sites within the framework of the three German Biodiversity Exploratories. An approach will be developed and exemplarily applied that copes with the enormous microbial diversity of soil. The approach is based on identifying and selecting (filtering) targets such as groups of organisms or genes encoding key microbial functions (here cellulolytic and lipolytic enzymes) before analyzing their distribution at different spatiotemporal scales in relation to vegetation type and use intensity. This strategy relies on three steps: (i) Construction of complex metagenomic libraries from microbial DNA extracted from soil samples covering different vegetation types and use intensities. (ii) Comparative screening of the libraries for exemplary groups of organisms and functions and metabolic profiling via snapshot sequencing are performed to identify (filter) targets that display differences and present distinct profiles between the sampling plots. (iii) Construction and use of microarrays and primers for monitoring the filtered targets in the Exploratories in relation to vegetation type, use intensity, and spatiotemporal variation.