Abstract
Airborne bacteria are significantly affected by meteorological and environmental conditions. However, there is little quantitative data available on the effects of these factors on airborne bacteria in urban ecosystems. In the present study, we analyzed weather-dependent changes in the composition of airborne bacterial communities using high throughput sequencing. Samples were collected before and after a period of constant hot weather at four selected sampling sites (YRBS, ZJGUSJC, TJCR, and BLQG) in Hangzhou. Our results show that the average amount of bacterial 16S rRNA gene copy numbers per m3 of air decreased significantly after constant high temperature. In addition, the number of operational taxonomic units and the Shannon–Wiener diversity indexes of the samples at all four selected sampling sites were significantly decreased after the heat event, showing notable impact on bacterial diversity. We also detected a significant increase in the abundances of spore-forming bacteria. Firmicutes increased from 3.7% to 9.9%, Bacillales increased from 2.6% to 7.6%, and Bacillaceae increased from 1.5% to 5.9%. In addition, we observed an increase in beta-Proteobacteria (18.2% to 50.3%), Rhodocyclaceae (6.9% to 29.9%), and Burkholderiaceae (8.1% to 15.2%). On the other hand, the abundance of alpha-Proteobacteria (39.6% to 9.8%), Caulobacteraceae (17.9% to 0.5%), Sphingomonadaceae (7.2% to 3.3%), and Xanthomonadaceae (3.0% to 0.5%) was significantly lower. Taken together, our data suggest that the composition of airborne bacterial communities varies greatly dependent on heat events, and that such communities include several species that are highly susceptible to high-temperature related stressors such as high air temperature, low relative humidity, and high intensity of solar radiation.
Highlights
Bioaerosols, which contribute as much as 25% to the atmospheric aerosols [1], are mixtures of viable and nonviable microbes as well as other types of biomass, including a wide range of antigenic compounds, such as dander, plant and insect debris, microbial toxins, and viruses [2]
Our data suggest that the composition of airborne bacterial communities varies greatly dependent on heat events, and that such communities include several species that are highly susceptible to high-temperature related stressors such as high air temperature, low relative humidity, and high intensity of solar radiation
Xihu district about 4 km from the city center; (3) Yan’an Road Business Street (YRBS) (30◦ 150 4500 N, 120◦ 90 5000 E), a commercial area and business district located at the center of Hangzhou city and in Xiacheng district; and (4) Breeze-ruffled Lotus at Quyuan Garden (BLQG) (30◦ 140 5500 N, 120◦ 70 5700 E), a scenic tourist area situated in Xihu district near West Lake, about 5 km from the city center
Summary
Bioaerosols, which contribute as much as 25% to the atmospheric aerosols [1], are mixtures of viable and nonviable microbes (e.g., bacteria, fungi, yeasts, and algae) as well as other types of biomass, including a wide range of antigenic compounds, such as dander, plant and insect debris, microbial toxins, and viruses [2]. Exposure to bacterial aerosols is associated with a wide array of adverse health effects, and many bacterial pathogens such as Streptococcus pneumoniae, Streptococcus pyogenes, Mycoplasma pneumoniae, Haemophilus influenzae, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Mycobacterium tuberculosis are often found in the air [11]. Apart from these pathogens, airborne microbial components Public Health 2018, 15, 2295; doi:10.3390/ijerph15102295 www.mdpi.com/journal/ijerph
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
