Community Structure and Ecological Distribution of Airborne Microbes in Autumn in Xi'an / 环境与健康杂志

ABSTRACT

Objective To understand the air microorganisms pollution and the community structure and distribution characteristics of outdoor airborne microbes in Xi'an in autumn.Methods Airborne microbes were sampled by fallen plates method in autumn,2006 in Xi'an at three typical sites,factories region,garden greenbelt region and main traffic region.Results The results showed that the total concentration of airborne microbes at the factories region and garden greenbelt region,main traffic region was 2 500 cfu/m~3,1 354 cfu/m~3 and 4 404 cfu/m~3 respectively.Bacteria and fungal genus were predominant.Gram positive bacteria were much more than Gram negative bacteria.There were 20 genera of bacteria and 8 fungal genus were detected. Micrococcui,Bacillus,Staphylococcus and Pseudornonus were predominant.The most frequently isolated fungal genus were Penicillium,Paecilomces,Cladosporium and Nonsporulatiny mycelia.The community structure of airborne fungal genus and the dominant genus in different function region was significantly different.The distribution characteristic of airborne microbe concentration in different function region was different.The concentration of airborne bacteria was significantly lower in garden greenbelt region than factories region and main traffic region,whereas the concentration of airborne fungi in garden greenbelt region was higher than that in factories region and main traffic region.Conclusion The distribution of the airbome microbes shows a characteristic of time and space,it is affected not only by the environment and pollution,but also by the other factors such as human activities,animals and plants.