Bioaerosol

About: Bioaerosol is a research topic. Over the lifetime, 1347 publications have been published within this topic receiving 34791 citations.

Evaluation of applicability of the Sartorius Airport MD8 sampler for detection of Bacillus endospores in indoor air

Abstract: This study was designed to evaluate the measuring range and lowest limit of detection of Bacillus endospores in the ambient room air when the Sartorius MD8 sampler, and two different culture methods for bacterial enumeration were used. Different concentrations of bioaerosol were generated inside the test chamber filled with either the high-efficiency particulate air (HEPA)-filtered air or with the ambient room air. The detection of endospores in the HEPA-filtered air was achievable: (1) when they were aerosolized at a concentration above 7.56 × 103 CFU/m3 and analyzed with spread plate method, and (2) when they were aerosolized at a concentration above 4.00 × 102 CFU/m3 and analyzed with pour plate method. The detection of endospores in the ambient room air was possible: (1) when they were aerosolized at a concentration above 9.1 × 103 CFU/m3 and analyzed with spread plate method, and (2) when they were aerosolized at a concentration above 5.6 × 102 CFU/m3 and analyzed with pour plate method. The microorganisms present in the ambient room air interfere with precise quantification of Bacillus endospores when their concentration is relatively low. The results of this study may be helpful in critical assessment of the results obtained from monitoring the air for bacterial endospores.

The sea to air bacteria transfer from the coastal waters.

Abstract: Bacteria transfer from the water into the air may play an important role in bioaerosol cycle. Bubbles raising through the water column collect bacteria but also other suspended material and transport them towards water surface. When the bubble burst at the water surface collected material are skimmed off the bubble to become highly enriched in jet and film drops. After ejection airborne droplets can evaporate and as small droplets can be transported even to remote locations. Such a stream of aerosol droplets may carry stream of bacteria scavenged from the water column. The fate of bacteria in the air may possibly depend on the environmental conditions like intensity of sunlight or ambient air humidity. In addition the wind speed might be responsible for both wave/bubble mediated production of marine originated droplets and their transport in the atmosphere. The evidences that bacteria are transferred from the breaking waves, in particular in the coastal zone, were observed during several field experiments conducted in 1994 and 1995 over the Gulf of Gdansk and the Baltic Sea coast. Enhanced sea to air bacteria transfer were noticed over the polluted waters where in addition gas supersaturations in the water were recorded. Further laboratory investigations of bacteria scavenge via bubbles produced by single capillary and by plume of bubbles produced by ceramic stone indicated high enrichment within both mesophile and psychrophile bacteria categories.

Effects of Surrounding Temperature on Antimicrobial Air Filters Coated with Sophora flavescens Nanoparticles

Abstract: Bioaerosols, such as bacterial and fungal cells and their spores, are components of indoor airborne particulate matter and have been associated with human health problems as well as various environmental issues. Natural antimicrobial products have been used in air filters for bioaerosol control. However, natural products may lose some function due to their sensitivity to environmental factors such as temperature and humidity. In this study, we investigated the effects of temperature on antimicrobial fiber filters coated with nanoparticles of a natural product, namely, Sophora flavescens extract. Inactivation efficiency decreased with increasing temperature and treatment time. A quantitative chemical analysis of the filters revealed that the quantities of antimicrobial compounds decreased noticeably, with a consequent decrease in antimicrobial activity. In addition, the S. flavescens nanoparticles on the filter fiber surface melted gradually as treatment time increased at temperatures >100°C. This change in nanoparticle morphology in turn affected the pressure and filtration efficiency of filters, both of which decreased with increasing temperature and treatment time. These results could provide a scientific basis for the improvement of indoor air-quality control using antimicrobial air filters coated with S. flavescens nanoparticles.