Comparison of Airborne Bacterial Diversity Collected by Passive and Active Air Sampling at Puy de Dôme, France

Kevin Dillon, Romie Tignat-Perrier, Muriel Joly, Sydonia Manibusan, Vincent Darbot, François Enault, Catherine Larose, Pierre Amato, GEDIMINAS MAINELIS, Rutgers, The State University of New Jersey

     Abstract Number: 319
     Working Group: Bioaerosols

Abstract
Aerosols containing bacteria (bioaerosols) can have impacts on atmospheric processes, as well as ecosystem and human health. Common methods to collected bioaerosols include impaction, liquid impingement, filtration, and electrostatic precipitation. These methods are used by active samplers that require power, but this requirement can represent a major constraint in field studies. Alternatively, passive samplers do not require power and can operate for long times. In this study, the Rutgers Electrostatic Passive Sampler (REPS), which captures particles by electrostatic attraction and gravitational settling, was deployed at the summit of Puy de Dôme (1465 m a.s.l., France) alongside an active PM10 sampler (~1000 L/min) collecting aerosols on a quartz fiber filter. The diversity of the airborne bacteria captured by both samplers across six weekly sampling periods was examined by 16S rRNA gene amplicon sequencing. The dominant phyla observed by both samplers were similar and included Firmicutes, Proteobacteria, and Actinobacteria. Overall, 12-63% of the total bacterial richness at the genus level was shared between the two samplers, depending upon a paired sample, i.e. sampling week. The dominant genera, including Lysinibacillus and Sphingomonas, were detected by both the active sampler and REPS, although their relative abundances for each paired sampler varied. The observed bacterial richness and diversity, as estimated through Shannon’s and Simpson’s indexes, were significantly greater in REPS samplers compared to the filter samples. The differences in diversity at the OTU level were not accounted for due to sampling week or local meteorological conditions. The results suggest that REPS could be used for simple and convenient sampling of bioaerosols, especially in remote areas and other locations with limited power access. Its data not only complement results obtained by active samplers but also provide additional insights.