Related Experiment Videos
Survival of bacteria during aerosolization
B Marthi1, V P Fieland, M Walter
1NSI Technology Services Corp., Corvallis, Oregon.
Applied and Environmental Microbiology
|November 1, 1990
Summary
Bacterial survival after aerosolization varied by species and environmental conditions. Pseudomonas syringae, Enterobacter cloacae, and Klebsiella planticola showed decreased survival, while Erwinia herbicola remained stable. Environmental factors significantly impact airborne microorganism dispersal.
Area of Science:
- Environmental microbiology
- Microbial ecology
- Aerosol science
Background:
- Commercial applications of microorganisms, including genetically engineered ones, often involve aerosolization.
- Understanding the impact of aerosol-induced stress on bacterial survival is crucial for risk assessment and application optimization.
Purpose of the Study:
- To investigate the survival rates of specific bacterial species when aerosolized.
- To determine the influence of environmental factors and preparation methods on bacterial survival during aerosolization.
- To provide data for optimizing enumeration and predicting the dispersal of airborne microorganisms.
Main Methods:
- Four nonrecombinant, antibiotic-resistant bacterial mutants (Enterobacter cloacae, Erwinia herbicola, Klebsiella planticola, Pseudomonas syringae) were aerosolized in a greenhouse.
- Bacterial populations were enumerated at distances up to 15 m from the spray site.
- Bacillus subtilis spores were used as tracers to account for dilution effects.
- Survival rates were analyzed in relation to environmental conditions (temperature, humidity), droplet size, and cell washing procedures.
Main Results:
- Viable counts of P. syringae, Enterobacter cloacae, and K. planticola significantly decreased over 15 m.
- Erwinia herbicola exhibited no significant decline in viable counts.
- P. syringae survival was highest at high relative humidity (70-80%) and low temperatures (12°C).
- Smaller droplet sizes and pre-aerosolization cell washing reduced bacterial survival.
Conclusions:
- Bacterial survival during aerosolization is species-dependent and significantly influenced by environmental parameters.
- Optimized conditions (high humidity, low temperature) can enhance the survival of certain airborne bacteria.
- Findings are valuable for developing methods to enumerate and predict the dispersal of airborne microorganisms, including genetically engineered strains.