title: Seasonal variability of bacteria in fine and coarse urban air particulate matter.
abstract: The current knowledge about the microbial communities associated with airborne particulate matter, particularly in urban areas, is limited. This study aims to fill this gap by describing the microbial community associated with coarse (PM10) and fine (PM2.5) particulate matter using pyrosequencing. Particulate matter was sampled on Teflon filters over 3 months in summer and 3 months in winter in Milan (Italy), and the hypervariable V3 region of the gene 16S rRNA amplified from the DNA extracted from the filters. The results showed large seasonal variations in the microbial communities, with plant-associated bacteria dominating in summer and spore-forming bacteria in winter. Bacterial communities from PM10 and PM2.5 were also found to differ from each other by season. In all samples, a high species richness, comparable with that of soils, but a low evenness was found. The results suggest that not only can the sources of the particulate influence the presence of specific bacterial groups but also that environmental factors and stresses can shape the bacterial community.
authors.affiliation: POLARIS Research Centre, Department of Environmental Sciences (DISAT), University of Milano-Bicocca, Piazza della Scienza, 1, 20126 Milan, Italy. andrea.franzetti@unimib.it
authors.forename: Andrea
authors.initials: A
authors.lastname: Franzetti
authors.forename: Isabella
authors.initials: I
authors.lastname: Gandolfi
authors.forename: Eleonora
authors.initials: E
authors.lastname: Gaspari
authors.forename: Roberto
authors.initials: R
authors.lastname: Ambrosini
authors.forename: Giuseppina
authors.initials: G
authors.lastname: Bestetti
mesh_terms: D000391:Air Microbiology; D000393:Air Pollutants / Q000009:adverse effects*; D001419:Bacteria / Q000254:growth & development / Q000302:isolation & purification*; D044822:Biodiversity; D002947:Cities; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004784:Environmental Monitoring / Q000379:methods; D020459:Genes, rRNA; D007558:Italy; D010316:Particle Size; D052638:Particulate Matter / Q000009:adverse effects*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012621:Seasons; D017422:Sequence Analysis, DNA
chemical_list: D000393:Air Pollutants; D004269:DNA, Bacterial; D052638:Particulate Matter; D012336:RNA, Ribosomal, 16S