Microorganisms in Fog and Aerosol at a Rural Site
THUONG CAO, Pierre Herckes, Ferran Garcia-Pichel, Derek Straub,
Arizona State University Abstract Number: 239
Working Group: Bioaerosols
AbstractResearch on microorganism-mediated conversion of organic compounds in atmospheric water (clouds and fog) has recently gained interest in the bioaerosol community. Most existing work has addressed remote environments (mainly Puy de Dôme, France) and few observations exist on microorganisms and bacterial biotransformation in the United States. In this study, fog and aerosol samples collected recurrently in Selinsgrove (Pennsylvania, USA) from June to November 2021 were investigated. Using 16S rRNA sequencing, we found that the bacterial community of fogs was different from that found in paired aerosol samples. Proteobacteria (Alpha-, and Beta-) largely dominated fog samples, while Alphaproteobacteria, Firmicutes, and Actinobacteria were abundant in aerosol samples. Total DNA concentration in fog samples increased with a greater liquid water content (LWC), which contrasts with the opposite trend observed between ionic content and LWC. Additionally, 31 bacterial species from 17 fog events were isolated onto R2A medium. In lab conditions, biodegradation of formaldehyde by these isolated bacteria tested in an artificial cloud medium at 17°C, resulted in divergent rates, varying from 0 to 10
-19 mol cell
-1 s
-1. This shows that some but not all bacteria in clouds can indeed contribute to biotransformation processes.