Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, 0002, South Africa.
Department of Environmental Sciences, University of Basel, 4056, Basel, Switzerland.
Microb Ecol. 2021 Nov;82(4):859-869. doi: 10.1007/s00248-021-01717-8. Epub 2021 Mar 3.
Dust is a major vehicle for the dispersal of microorganisms across the globe. While much attention has been focused on microbial dispersal in dust plumes from major natural dust sources, very little is known about the fractionation processes that select for the "dust microbiome." The recent identification of highly emissive, agricultural land dust sources in South Africa has provided the opportunity to study the displacement of microbial communities through dust generation and transport. In this study, we aimed to document the microbial communities that are carried in the dust from one of South Africa's most emissive locations, and to investigate the selective factors that control the partitioning of microbial communities from soil to dust. For this purpose, dust samples were generated at different emission sources using a Portable In-Situ Wind Erosion Lab (PI-SWERL), and the taxonomic composition of the resulting microbiomes was compared with the source soils. Dust emission processes resulted in the clear fractionation of the soil bacterial community, where dust samples were significantly enriched in spore-forming taxa. Conversely, little fractionation was observed in the soil fungal communities, such that the dust fungal fingerprint could be used to identify the source soil. Dust microbiomes were also found to vary according to the emission source, suggesting that land use significantly affected the structure and fractionation of microbial communities transported in dust plumes. In addition, several potential biological allergens of fungal origin were detected in the dust microbiomes, highlighting the potential detrimental effects of dust plumes emitted in South Africa. This study represents the first description of the fractionation of microbial taxa occurring at the source of dust plumes and provides a direct link between land use and its impact on the dust microbiome.
尘埃是微生物在全球范围内传播的主要载体。虽然人们已经关注了主要自然尘埃源的尘埃羽流中的微生物传播，但对于选择“尘埃微生物组”的分馏过程却知之甚少。最近在南非发现了高排放的农业土地尘埃源，这为研究通过尘埃生成和传输来置换微生物群落提供了机会。在这项研究中，我们旨在记录从南非最具排放性的地点之一携带的尘埃中的微生物群落，并研究控制土壤微生物群落向尘埃分配的选择性因素。为此，我们使用便携式原位风蚀实验室（PI-SWERL）在不同的排放源处生成尘埃样本，并将所得微生物组的分类组成与源土壤进行了比较。尘埃排放过程导致土壤细菌群落明显分馏，其中尘埃样本中明显富含孢子形成类群。相比之下，土壤真菌群落的分馏很少，因此尘埃真菌指纹可用于识别源土壤。还发现尘埃微生物组根据排放源而变化，这表明土地利用显著影响了尘埃羽流中运输的微生物群落的结构和分馏。此外，在尘埃微生物组中还检测到了几种潜在的真菌来源的生物过敏原，突出了南非尘埃羽流排放的潜在有害影响。这项研究代表了首次描述尘埃羽流源处微生物分类群的分馏，并提供了土地利用及其对尘埃微生物组影响之间的直接联系。
