The air contains many different types of bacteria and other microorganisms. Air is usually considered a minor ecological reservoir for microorganisms and very little is known about the activity of airborne microorganisms. Most research on air microorganisms focuses on the presence and transmission of pathogens that may cause disease. There has been very little exploration of bacterial activity and growth in the natural air. The objective of this project is to determine whether the bacteria in natural air environments are active and capable of growing while airborne. A one-year preliminary study will be conducted to answer the following questions: Are naturally occurring airborne bacteria active and do they multiply? Do airborne microorganisms degrade organic pollutants present in the air? How do bacteria in air actively respond to humidity and temperature and presence of specific chemical pollutants? Experiments will be performed using air collected from sites near significant sources of aerial pollutants. Stainless steel gas-phase chambers with humidity, temperature and light control will be used. Growth and activity of bacteria will be measured and DNA sequencing will be used to determine whether certain bacterial species become more prominent in the community makeup during exposure to chemicals, thus implying responsibility for the biodegradation.
This study will lead to discovery of the existence and extent of native bacterial activity in air, which is an all but unexplored component of the biosphere. Bacteria in air may degrade pollutants and have important functions in climate processes. The results of this study will serve as the basis for initial estimates of the global impact of degradation by aerial microorganisms on the cycling of pollutants, a currently unknown contribution. This project is also a starting point for novel future studies to explore the bulk aerial and cloud environment with respect to microbial ecology, pollutant degradation, climate processes, expression of genes in air that could be used as biomarkers, and ultimately, impact on human health and implications for biosecurity. Currently, very little data are available on any of these topics. The broader impacts of this research project will include recruitment of graduate and undergraduate students to carry out the project, incorporation of project concepts in the co-PIs new laboratory course on Bioaerosol Technology, and incorporation of the project in an outreach workshop that the PI conducts as part of a Rutgers University orientation program for incoming female freshmen engineering and science majors.