AAAR 32nd Annual Conference
September 30 - October 4, 2013
Oregon Convention Center
Portland, Oregon, USA
Abstract View
Differential Proteomic Analysis of Sphingomonas Aerolata Bioaerosols
Valdis Krumins, Sjef Boeren, Peter Schaap, Hauke Smidt, Gediminas Mainelis, Lee Kerkhof, DONNA FENNELL, Rutgers, The State University of New Jersey
Abstract Number: 114 Working Group: Bioaerosols: Characterization and Environmental Impact
Abstract The atmosphere contains substrates such as volatile organic compounds (VOCs) that could support metabolic activity of living bioaerosols. This study examined the proteomic response of bacterial aerosols during aerosolization in the presence of a VOC. Sphingomonas aerolata strain NW12 (AJ429240.1), a psychrotolerant bacterium isolated from ambient air and obtained from DSMZ-German Collection of Microorganisms and Cell Cultures, was used as a model atmospheric organism. The genome of Sphingomonas aerolata was sequenced using the Illumina HiSeq2000 platform. The genome was annotated and a theoretical proteome consisting of approximately 3000 proteins was obtained. Sph. aerolata cells were grown in minimal media with acetic acid as the sole substrate, and were aerosolized into rotating gas-phase bioreactors. The bacteria were incubated in the airborne state with either ethanol or no substrate. After two days, cells were collected using membrane filters (Supor, Pall, Port Washington, NY). Protein was extracted from the bacterial aerosol particles directly from the membrane. Peptides were obtained through in-gel digestion and analyzed by liquid chromatography-mass spectrometry. Putative proteins were identified and quantified in liquid controls, no-substrate aerosolized controls, and ethanol-fed aerosolized treatments. The gas-phase rotating reactors were able to maintain 20 to 80 x 10^6 cells airborne over several days, enough for adequate protein capture. Collection of cells via Supor membranes and extraction of proteins directly from the membranes did not interfere with downstream processing. Approximately 400 putative proteins were identified from the aerosolized cells, allowing comparison of different treatments. Preliminary results from one set of reactor experiments revealed that proteins involved in alcohol metabolism, central pathways in cellular metabolism and ribosome synthesis were more abundant in aerosolized cells fed ethanol than in aerosolized cells with no added substrate, suggesting metabolic activity of bacteria in the airborne state.