Studies On Airborne Microbial Diversity At Different Functional Regions In Qingdao

Airborne microbes are main biological components of ecosystems. They not onlyhave important ecosystem functions, but also were the risk to the human health. Inrecent years, foreign scholars have done some researches on microbial sourcesincluding particle size, influencing factors, toxicology, etc. Chinese scholars alsoinvestigate the flora and pollution of urban airborne microbes, pollution and evaluationof airborne microbes at landfill, microbial aerosol mode of transmission in livestockpoultry housing, the impact of environmental factors on airborne microbes, etc.However, at home and abroad, the studies based on the airborne microbial diversitywere in the phase of practical accumulation and theoretical frame construction. Therefore,bliulding the appropriate methods to study airborne microbial diversity not only haveimportant theoretical significance to control microbial contamination and diseases,improve environmental quality, maintain human health, and improve the industrial andagricultural production, but can also lay the foundation for further development.In order to determine the metabolic characteristics and community diversities ofairborne microbes in different functional regions of Qingdao, monitoring points were setup in five different functional regions (urban streets, coastal area, drinking water sourcearea, municipal landfill, and artificial wetlands). Airborne microbes were collected bySAS ISO100in each season of2013. The carbon source metabolic characteristics,functional diversity of microbial community, and their relationship with environmentalfactors were systematically analyzed by the BIOLOG method. At the same time, theairborne microbial structure and phylogeny were analysed by16S/18S rDNA clonelibrary and RFLP method in two functional aeras of Qingdao (wetlands, urban streets).The results were as below.(1) At the same season the types and levels of carbon metabolic profiles weredifferent in different regions of Qingdao. The levels of carbon metabolic profiles ofvernal airborne microbes at artificial wetlands were higher than those in other locations,and carbon catabolic types were rich. The types and levels of carbon metabolic profiles were also different at different seasons. On the whole, for urban streets, and artificialwetlands, the levels of carbon metabolization in summer were higher than other seasons.For municipal landfill, coastal area and drinking water source area, the levels of carbonmetabolization in the autumn were higher than others season.(2) The Shannon index, Simpson index were similar in different regions at thesame season, while the Mclntosh index was different, which showed that the uniformitywas different; In urban streets, coastal area, artificial wetlands and municipal landfill,the Shannon index, Simpson index were similar, while the Mclntosh index was differentat different seasons, The three indexes were similar in the drinking water source area. Itindicates that the uniformity was different in urban streets, coastal area, artificialwetlands, and municipal landfill.(3) In different functional areas at the same season, carbon metaboliccharacteristics of airborne microbes were different, which caused the differences incharacteristics of carbon metabolic profiles. The key carbon source was carboxylic acidswhich caused the differences in characteristics of carbon metabolic profiles in springand winter, while carbohydrates in summer, amino acids in autumn; In same functionalarea at different seasons, the main carbon source types were different which caused thedifferences in characteristics of carbon metabolic profiles. Among all, amines/amidesand carboxylic acids at artificial wetlands, carboxylic acids and carbohydrates atdrinking water source area, amino acids at urban street, carbohydrates andamines/amides at coastal area, carbohydrates and polymers at municipal landfill.(4) Clone library could more factually reflect microbial community structure ofenvironmental samples. Comparing the clones sequence in the NCBI, it was showedthat some bacteria, fungi had not yet been cultured, classified, and identificated in urbanstreet, artificial wetlands.(5) There was a huge difference of airborne microbial community in differenturban ecosystems. In different functional regions of the same city, airborne microbialcommunity, conditional pathogenic microorganisms, and pathogens all had seasonal and regional differences.