| Haze has a serious impact on human health.As an important component of particulate matter,airborne microorganism has drawn people's attention gradually.Airborne microorganisms can attach to the particles for migration.Studying the distribution of microbial community structure in airborne particles and its influencing factors in different regions will help to fully understand the spatial distribution of airborne microorganisms and provide scientific guidance for subsequent air pollution control and protection policy formulation.However,there are few researches on the structure and influential factors of airborne microbial community in different regions,especially lacking the studies on typical urban areas in large scale.In this paper,we selected eight typical cities(Shenyang,Beijing,Dingxi,Zhengzhou,Zhoushan,Hangzhou,Kunming and Shenzhen)in northeast,northwest,southeast and southwest of China.Airborne microbial community structure was studied from three aspects:longitude difference,latitude difference and land-sea difference.Besides Hangzhou was selected to study the distribution of air microbial community in the typical functional area(scenic area and commercial-residential mixed area).Then,we established a statistical model between environmental factors and airborne microbial community.Combined with the receptor model,we systematically study the impact of environmental factors on the microbial communities in typical functional areas and typical cities.The main conclusions are as follows:1.The differences of airborne microbial community structure between different functional areas and different cities have been provedHigh-throughput sequencing studied the airborne microbial community structure in eight cities and two functional areas in Hangzhou,evaluated the diversity of microbial communities,and from the longitude,latitude,land and sea differences were compared and analyzed,details as follows:1)The relative abundances of the top ten dominant bacterial genera in two functional areas of Yunqi(scenic area)and Zhaohui(mixed commercial area)were Enterococcus,Acinetobacter,Methylobacterium,Deinococcus,Rubellimicrobium,Lysobacter,Sphingomonas,Pseudomonas,Streptomyces,Kaistobacter.Among them,the relative abundance of 50%bacteria dominant genus was higher in Yunqi area,and the relative abundance of the remaining 50%bacterial dominant genera was higher in Zhaohui area.The relative abundances of the top ten dominant fungal genera in Yunqi area and Zhaohui area were Cladosporium,Bjerkandera,Penicillium,Phlebia,Arthrinium,Candida,Aspergillus,Postia,Antrodiella,Alternaria.The abundances of the dominant fungal genera Bjerkandera and Penicillium in Yunqi area were higher than those in Zhaohui area.The abundances of the dominant fungal genera Cladosporium and Arthrinium in Zhaohui area were higher than those in Yunqi area.2)The relative abundances of the top ten dominant bacterial genera in eighttypical cities were Acinetobacter,Streptomyces,Propionibacterium,Prauseria,Bacillus,Corynebacterium,Microbispora,Saccharopolyspora,Methylobacterium,Pseudomonas.Among the cities with different latitudes,the relative abundances of two dominant bacteria genera in Beijing were higher than those in Zhengzhou.The relative abundances of eight dominant bacterial genera in Zhengzhou were higher than those in Beijing.The relative abundances of six dominant bacterial genera in Dingxi of Gansu Province were higher than those in Kunming.The relative abundances of four dominant bacterial genera in Kunming were higher than those in Dingxi of Gansu Province.Among the cities with different longitudes,the relative abundances of three dominant bacterial genera in Beijing were higher than those in Shenyang.The relative abundances of seven dominant bacterial genera in Shenyang were higher than those in Beijing.The relative abundances of two dominant bacteria genera in Dingxi of Gansu Province were higher than those in Zhengzhou.The relative abundances of eight dominant bacteria genera in Zhengzhou were higher than those in Dingxi of Gansu Province.Among the cities with land-sea difference,the relative abundances of four dominant bacteria genera in Hangzhou were higher than those in Zhoushan.The relative abundances of six dominant bacteria genera in Zhoushan were higher than those in Hangzhou.3)Shannon index was used to evaluate the diversity of microbial communities in the typical functional areas.The diversity of the bacterial communities in Zhaohui was slightly higher than that in Yunqi.The diversity of fungal communities in Yunqi was slightly higher than that of Zhaohui.Metastat analysis showed that the number of significantly differential bacterial genera in Yunqi area were 4.06 times of that in Zhaohui area,while the number of significantly differential fungal genera in Zhaohui area were 1.60 times of that in Yunqi area.4)From three aspects of latitude,longitude and land-sea difference,the diversity of bacterial communities in typical cities was analyzed.Among the cities with different latitudes,the diversity of bacterial communities in Beijing was similar to that in Zhengzhou.The diversity of bacterial communities in Dingxi of Gansu was higher than that in Kunming.Among the cities with different longitudes,the diversity of bacterial communities in Beijing was similar to that in Shenyang.The diversity of bacterial communities in Dingxi was slightly higher than that in Zhengzhou.Among the cities with different land-sea properties,the diversity of bacterial communities in Zhoushan was slightly higher than that in Hangzhou.Considering the distribution of dominant microbial community and the diversity of microbial community in eight typical cities,we selected three cities(Hangzhou,Shenyang and Kunming)with significant differences and analyzed the significant differential bacteria in any two of them.The results showed that the types of significantly differential bacteria in Kunming and Shenyang were similar,but were generally less than those in Hangzhou.2.The effects of environmental factors on the microbial community structure in typical functional areas were exploredUsing multivariate regression and logistic polynomial analysis,the effects of environmental factors in typical functional areas on the airborne microbial community structure were studied.The mixed receptor model was used to analyze the impact of regional transport on the airborne microbial community structure in typical functional areas,details as follows:1)Multiple regression analysis showed that ozone concentration and wind direction comprehensively influenced the diversity of airborne bacterial communities and airborne fungi community in overall regions,and the effect of ozone concentration was greater than that of wind direction.In the area of Yunqi,the diversities of bacterial and fungal communities were mainly influenced by ozone concentration.Ozone concentration had a significantly negative effect on the diversity of bacterial community(p<0.01),and had a significantly positive effect on the diversity of fungal communities(p<0.01).In the Zhaohui area,temperature affected the diversity of airborne bacterial communities;relative humidity and PM2.5 concentration comprehensively affected the diversity of airborne fungi community,and the influence of relative humidity was greater than that of PM2.5 concentration.2)Logistic polynomial regression analysis showed that ozone concentration and carbon monoxide concentration comprehensively influenced the abundance of airborne dominant bacterial flora in overall regions.Ozone concentration and wind direction comprehensively influenced the abundance of airborne dominant fungal flora in overall regions.Ozone concentration and carbon monoxide concentration comprehensively influenced the abundance of airborne dominant bacterial flora in Yunqi area.Ozone concentration and wind direction synthetically influenced the abundance of airborne dominant fungal flora in Yunqi area.In Zhaohui area,temperature and wind speed comprehensively influenced the abundance of airborne dominant bacterial flora,while temperature and wind direction comprehensively influenced the abundance of airborne dominant fungal flora.3)Mixed receptor model analysis showed that the impact of regional transmission on the diversity of bacterial community diversity in different functional areas was quite different.But the impact of regional transmission had little difference on the diversity of fungal communities in different functional areas.For bacteria,the main potential source of Yunqi was the northeast area.The main potential source of Zhaohui was the northwest area.For fungi,the main potential source for Yunqi was northwest area.The main potential source for Zhaohui was northwest area.4)Mixed receptor pattern analysis showed that there was no significant difference in the effect of regional transmission on the abundance of airborne differential bacterial flora and differential fungal flora in different functional areas.According to the differential bacterial flora of Yunqi and Zhaohui area,the main potential sources of Yunqi and Zhaohui area were both northeast and part of northwest area.According to the differential fungal flora of Yunqi and Zhaohui area,the main potential sources of Yunqi and Zhaohui area were both the south area.3.The effects of environmental factors on the airborne microbial community structure in typical cities were exploredUsing multivariate regression and logistic polynomial analysis,the effects of environmental factors in typical cities on the airborne microbial community structure were studied.The mixed receptor model was used to analyze the impact of regional transport on the airborne microbial community structure in typical cities,details as follows:1)Multiple regression analysis showed that the temperature influenced the diversity of airborne bacterial community in Hangzhou.The temperature and air pressure comprehensively affected the diversity of bacterial community in Shenyang.We did not find environmental factors that significantly affected the diversity of airborne bacterial communities in Kunming.2)Logistic polynomial regression analysis showed that wind speed and temperature comprehensively affected the abundance of airborne dominant bacterial flora in Hangzhou.In Shenyang,ozone concentration,PM2.5 concentration,wind direction and temperature comprehensively affected the abundance of airborne dominant bacterial flora.Carbon monoxide concentration and wind direction comprehensively affected the abundance of airborne dominant bacterial flora in Kunming.3)Mixed receptor pattern analysis showed that regional transmission had an impact on the diversity of airborne bacterial communities in different cities.The main potential source of airborne bacterial communities in Hangzhou was from the north area.Airborne bacterial communities in Shenyang and Kunming also contributed to that in Hangzhou,while Shenyang contributed less and Kunming contributed more.The southeast and southwest area contributed a large amount to the airborne bacterial communities in Kunming.The northwestern and part of western area contributed a lot to the airborne bacterial communities in Shenyang.4)Mixed receptor pattern analysis revealed that regional transmission had an impact on the abundance of airborne differential bacterial flora in different cities.For the differential bacterial flora in Hangzhou and Kunming,the main potential sources of airborne bacterial communities in Hangzhou were northeast and southwest area,while Kunming also contributed a little to the airborne bacterial communities in Hangzhou.A small area of the Southern area contribute a lot to the airborne bacterial communities in Kunming.Comparing the airborne bacterial communities in Hangzhou and Shenyang,the northeast and southwest area contributed a lot to the airborne bacterial communities in Hangzhou while Shenyang also made a small contribution.The northwest area contributed a lot to the airborne bacterial communities in Shenyang.Comparing the airborne bacterial communities in Kunming and Shenyang,the south area contributed a lot to the airborne bacterial communities in Kunming.The north and southwest area contributed a lot to the airborne bacterial communities in Shenyang. |
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