Volume 15, No. 4, August 2015, Pages 1460-1468 PDF(274 KB)
Laboratory Study of Effects of Atmospheric Pollutants on Ice Nucleation Activity of Bacteria
Rui Du1, Yaling Wang1, Jiming Sun2,3, Pengrui Du1, Zedong Lu1, Zongmin Liang1, Ziming Li1
1 College of Resources and Environment, University of Chinese Academy Sciences, Beijing, China
2 Key Laboratory of Cloud-Precipitation Physics and Severe Storms (LACS), Institute of Atmospheric Physics, Chinese Academy Sciences, Beijing, China
3 Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Nanjing University of Information Science and Technology, China
- Test the ice nucleation activity (INA) of bacteria.
- Typical atmospheric organic pollutants impact on INA bacteria.
- The mixed organic pollutants impact on INA bacteria.
Ice nuclei of some bacterial origin as ice catalysts can initiate ice nucleation at temperatures as warm as –2°C in certain laboratory experiments. The ice nucleation activities of airborne bacteria in the real atmosphere may be different from those experiments. To estimate the impact of typical atmospheric pollutants including monocarboxylic acids (MCAs), dicarboxylic acids (DCAs) and ammonia sulfate on ice nucleation activity of P.syringae pv lachrymans and P.syringae pv.panici, we have conducted some experiments by means of the modified Vali’s droplet freezing testing method in the immersion freezing mode with the mixture of the pure water and the polluted water. Our results show that the ice nucleation activity of bacterial origins can be regulated by such pollutant compounds even though the onset freezing temperatures of water droplets mainly depend on the concentrations of ice nucleation-active bacteria. Atmospheric acids can decrease ice nucleation activity of P.syringae pv lachrymans and P.syringae pv.panici. However, the onset freezing temperatures of water droplets immersed with ice nucleation-active P.syringae pv lachrymans will be enhanced by the low concentration of such atmospheric pollutants.
Pollutant; Ice nuclei; Droplet freezing test; Immersion freezing; Ice nucleation-active bacteria.