AAAR 37th Annual Conference October 14 - October 18, 2019 Oregon Convention Center Portland, Oregon, USA
Abstract View
Quantifying the Relationship between Physicochemical Properties and Biological Decay in Populations of Bioaerosol Droplets
MARA OTERO-FERNANDEZ, Allen E. Haddrell, Richard Thomas, Henry Oswin, Jonathan P. Reid, University of Bristol
Abstract Number: 140 Working Group: Bioaerosols
Abstract The evaporation and rehydration processes occurring during a droplet’s lifetime produce rapid changes in the particles’ size that will affect most of the physicochemical properties of the biological aerosol (i.e. solute concentration, density, viscosity, temperature, etc.). These dynamics could also impact the viability of the microbes contained within the bioaerosol droplets and will influence the length of time microorganisms survive during aerosol transport. To be presented is a novel approach to probe aerosols containing Escherichia coli MRE162 that can be extended to other microorganisms. It combines two different technologies to interconnect the complexity of aerosol dynamics with bioaerosol longevity as a function of time, environmental conditions and aerosol composition, aiming to fully understand the mechanisms of airborne transmission.
The CK-EDB (Comparative Kinetics Electrodynamic Balance) and CELEBS (Controlled Electrodynamic Levitation and Extraction of Bio-aerosol onto a Substrate) technologies are based on Electrodynamic Balance Levitation for droplet suspension and utilize droplet-on-demand aerosol generators to produce droplets with high monodisperse size distribution (Fernandez et al., 2019). By using the CK-EDB, it is possible to measure the changes in the physicochemical properties of the bio-aerosol droplets during the drying and thermodynamic equilibrium processes with the aim to ultimately interrelate this information with the biological decay responses measured by the CELEBS.
Results outlined in this presentation will contribute to understand the impact of several variables such as: (a) evaporation kinetics, (b) changes in aerosol composition, (c) presence of surfactants and (d) changes in droplet temperature on the longevity of E. coli in the aerosol phase, featuring some of the benefits of this novel methodology including: (1) the characterization of the first phase of microbial death during evaporation; (2) quantifying the complete droplet composition, from the single droplet to the population level; (3) minimizing stresses during bioaerosol aerosolization and sampling.