Culturable Airborne Bacteria in Outdoor Environments in Beijing, China

Abstract

Airborne bacteria are important biological components of bioaerosol and play an important role in ecosystem. Bacteria at a high concentration in the atmosphere can result in biological air pollution and all kinds of diseases. In this study, a systematical survey on the culturable airborne bacteria was carried out for 1 year at three sites in Beijing urban area. Results showed that concentrations of culturable bacteria ranged from 71 colony forming units (CFU)/m(3) to 22,100 CFU/m(3), and the mean was 2,217 CFU/m(3). Bacterial concentrations at the human activity-enriched site (RCEES) and the highly trafficked site (XZM) were virtually the same point. They were significantly higher than those at the greener site (BBG). Significant variation in bacterial concentrations in different seasons was observed at RCEES and XZM with higher concentrations in summer and autumn. In a single day, significantly lower concentrations were detected at 13:00 hours through all sampling sites. In this study, 165 species in 47 genera of culturable bacteria were identified. Micrococcus was one of the most dominant bacterial groups and contributed to approximately 20 approximately 30% of the total bacterial concentration, followed by Staphylococcus, Bacillus, Corynebacterium, and Pseudomonas. The bacterial species with a high concentration percentage included Micrococcus luteus and Micrococcus roseus.

Air Microbial Contamination at the Holy Mosque, Makkah, Saudi Arabia

“…This is attributed to the absence of direct human disturbances, and good natural ventilation. Generally microbial concentrations in the urban environment are influenced by human activities 40 , and their composition varies in different cities 41 .In the present study there were unclear correlations found between airborne microorganisms and meteorological factors. This is attributed to the influence of irregular disturbances and human activities, which may have more influence on microbial concentrations than meteorological factors near the holy mosque.…”

Primary biological aerosol particles in the atmosphere: a review

“…Culturing methods in general find more Gram-positive bacteria (e.g. Mancinelli and Shulls, 1978;Atlas and Bartha, 1997;Atlas and Bartha, 1997;Fuzzi et al, 1997;Kellogg and Griffin, 2006;Amato et al, 2007b;Fang et al, 2007;Fahlgren et al, 2010), whereas culture-independent techniques primarily find Gram-negative bacteria (e.g. Radosevich et al, 2002;Maron et al, 2005;Brodie et al, 2007;Despre´s et al, 2007;Fierer et al, 2008;Fahlgren et al, 2010).…”

“…Bacterial diversity in rural areas is generally higher than at urban sites (Despre´s et al, 2007). Still, the concentration of bacteria seems often to be higher in urban than in rural environments (Bovallius et al, 1978;Chihara and Someya, 1989;di Giorgio et al, 1996;Shaffer and Lighthart, 1997;Fang et al, 2007;Fahlgren et al, 2010), even when the samples are taken in the same geographic region. However, opposite trends have also been found: For example, Rosas et al (1993) described that bacterial concentrations in rural environments are higher than in urban sites.…”

“…However, opposite trends have also been found: For example, Rosas et al (1993) described that bacterial concentrations in rural environments are higher than in urban sites. There is also evidence that the bacterial concentrations in the urban environment are influenced by human activities (Bovallius et al, 1978;Fang et al, 2007). Different cities do vary in their bacterial composition and abundance (Brodie et al, 2007); thus, there can be no single, typical description of urban bacterial composition.…”

“…Areas with heavy vehicular traffic or sewage pollution have much higher concentrations of airborne bacteria, with a weaker or non-existent seasonal cycle, as compared to concentrations in more naturally influenced areas such as urban parks, forests or coastal sites (e.g. Miquel, 1883;Shaffer and Lighthart, 1997;Harrison et al, 2005;Fang et al, 2007).…”