Department of Landscape, The University of Sheffield, Sheffield, UK.
inVIVO Planetary Health of the Worldwide Universities Network (WUN), West New York, New Jersey, USA.
Environ Health Perspect. 2020 Nov;128(11):117008. doi: 10.1289/EHP7807. Epub 2020 Nov 25.
Exposure to a diverse environmental microbiome is thought to play an important role in "educating" the immune system and facilitating competitive exclusion of pathogens to maintain human health. Vegetation and soil are key sources of airborne microbiota--the aerobiome. A limited number of studies have attempted to characterize the dynamics of near surface green space aerobiomes, and no studies to date have investigated these dynamics from a vertical perspective. Vertical stratification in the aerobiome could have important implications for public health and for the design, engineering, and management of urban green spaces.
The primary objectives of this study were to: ) assess whether significant vertical stratification in bacterial species richness and evenness (alpha diversity) of the aerobiome occurred in a parkland habitat in Adelaide, South Australia; ) assess whether significant compositional differences (beta diversity) between sampling heights occurred; and ) to preliminarily assess whether there were significant altitudinal differences in potentially pathogenic and beneficial bacterial taxa.
We combined an innovative columnar sampling method at soil level, 0.0, 0.5, 1.0, and , using passive petri dish sampling to collect airborne bacteria. We used a geographic information system (GIS) to select study sites, and we used high-throughput sequencing of the bacterial 16S rRNA gene to assess whether significant vertical stratification of the aerobiome occurred.
Our results provide evidence of vertical stratification in both alpha and beta (compositional) diversity of airborne bacterial communities, with diversity decreasing roughly with height. We also found significant vertical stratification in potentially pathogenic and beneficial bacterial taxa.
Although additional research is needed, our preliminary findings point to potentially different exposure attributes that may be contingent on human height and activity type. Our results lay the foundations for further research into the vertical characteristics of urban green space aerobiomes and their implications for public health and urban planning. https://doi.org/10.1289/EHP7807.
人们认为，接触多样化的环境微生物群对于“教育”免疫系统并促进病原体的竞争排除以维持人类健康起着重要作用。植被和土壤是空气微生物群（气生菌群）的主要来源。少数研究试图描述近地表绿地气生菌群的动态变化，但迄今为止尚无研究从垂直角度调查这些动态变化。气生菌群的垂直分层可能对公共卫生以及城市绿地的设计、工程和管理具有重要意义。
本研究的主要目的是：评估在南澳大利亚阿德莱德的一个公园栖息地中气生菌群的细菌物种丰富度和均匀度（α多样性）是否存在显著的垂直分层；评估采样高度之间是否存在显著的组成差异（β多样性）；并初步评估潜在的致病和有益细菌类群是否存在显著的海拔差异。
我们结合了一种创新的柱状采样方法，在土壤水平、0.0、0.5、1.0 和 处使用被动培养皿采样收集空气细菌。我们使用地理信息系统（GIS）选择研究地点，并使用细菌 16S rRNA 基因的高通量测序来评估气生菌群是否存在显著的垂直分层。
我们的结果提供了证据，证明了空气细菌群落的 α 和 β（组成）多样性存在垂直分层，多样性随高度大致降低。我们还发现潜在的致病和有益细菌类群存在显著的垂直分层。
尽管需要进一步的研究，但我们的初步发现表明，可能存在不同的暴露属性，这些属性可能取决于人类的身高和活动类型。我们的研究结果为进一步研究城市绿地气生菌群的垂直特征及其对公共卫生和城市规划的影响奠定了基础。https://doi.org/10.1289/EHP7807.
