title: Bacterial characterization in ambient submicron particles during severe haze episodes at Ji'nan, China.
abstract: In January 2014, severe haze episodes which sweep across Chinese cities have attracted public concern and interest at home and abroad. In addition to the physicochemical properties of air pollutants, bacteria are thought to be responsible for the spread of respiratory diseases and various allergies. We attempted the bacterial characterization of submicron particles (PM0.18-0.32, PM0.32-0.56, and PM0.56-1) under severe haze episodes using high-throughput sequencing and real-time quantitative PCR detecting system based on 21 samples collected from January to March 2014 at Ji'nan, China. The high bacterial concentration in PM0.32-0.56(7314cells m-3), PM0.18-0.32(7212cells m-3), and PM0.56-1(6982cells m-3) showed significant negative correlations with SO2, NO2,and O3. Under sufficient sequencing depth, 37 phyla, 71 classes, 137 orders, 236 families, and 378 genera were classified, and the bacterial community structure varied significantly in different size fractions. For example, Holophagaceae (Acidobacteria) in PM0.32-0.56showed 6-fold higher abundance than that in PM0.18-0.32. Moreover, functional categories and bacterial species (Lactococcus piscium, Pseudomonas fragi, Streptococcus agalactiae, and Pseudomonas cichorii) that may potentially be responsible for infections and allergies were also discovered. Source track analysis showed that the ambient bacteria mainly originated from soils, leaf surfaces, and feces. Our results highlighted the importance of airborne microbial communities by understanding the concentration, structure, ecological and health effects, especially those in submicron particles during haze episodes.
authors.affiliation: Environment Research Institute, School of Environmental Science and Engineering, Shandong University, Ji'nan 250100, China.
authors.forename: Caihong
authors.initials: C
authors.lastname: Xu
authors.affiliation: Environment Research Institute, School of Environmental Science and Engineering, Shandong University, Ji'nan 250100, China.
authors.forename: Min
authors.initials: M
authors.lastname: Wei
authors.affiliation: Environment Research Institute, School of Environmental Science and Engineering, Shandong University, Ji'nan 250100, China; Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP), Fudan Tyndall Centre, Department of Environmental Science & Engineering, Fudan University, Shanghai 200433, China. Electronic address: jmchen@sdu.edu.cn.
authors.forename: Jianmin
authors.initials: J
authors.lastname: Chen
authors.affiliation: Environment Research Institute, School of Environmental Science and Engineering, Shandong University, Ji'nan 250100, China.
authors.forename: Xinfeng
authors.initials: X
authors.lastname: Wang
authors.affiliation: Environment Research Institute, School of Environmental Science and Engineering, Shandong University, Ji'nan 250100, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Zhu
authors.affiliation: Environment Research Institute, School of Environmental Science and Engineering, Shandong University, Ji'nan 250100, China.
authors.forename: Jiarong
authors.initials: J
authors.lastname: Li
authors.affiliation: Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP), Fudan Tyndall Centre, Department of Environmental Science & Engineering, Fudan University, Shanghai 200433, China.
authors.forename: Lulu
authors.initials: L
authors.lastname: Zheng
authors.affiliation: Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP), Fudan Tyndall Centre, Department of Environmental Science & Engineering, Fudan University, Shanghai 200433, China.
authors.forename: Guodong
authors.initials: G
authors.lastname: Sui
authors.affiliation: Environment Research Institute, School of Environmental Science and Engineering, Shandong University, Ji'nan 250100, China.
authors.forename: Weijun
authors.initials: W
authors.lastname: Li
authors.affiliation: Environment Research Institute, School of Environmental Science and Engineering, Shandong University, Ji'nan 250100, China.
authors.forename: Wenxing
authors.initials: W
authors.lastname: Wang
authors.affiliation: Environment Research Institute, School of Environmental Science and Engineering, Shandong University, Ji'nan 250100, China.
authors.forename: Qingzhu
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Environment Research Institute, School of Environmental Science and Engineering, Shandong University, Ji'nan 250100, China; Institut de Combustion, Aérothermique, Réactivité et Environnement, CNRS, 45071 Orléans cedex 02, France.
authors.forename: Abdelwahid
authors.initials: A
authors.lastname: Mellouki
mesh_terms: D000391:Air Microbiology; D000397:Air Pollution / Q000032:analysis*; D001419:Bacteria / Q000145:classification / Q000302:isolation & purification*; D002681:China; D002947:Cities; D004784:Environmental Monitoring; D010316:Particle Size; D052638:Particulate Matter
chemical_list: D052638:Particulate Matter
keywords: Bacterial community; Bioaerosol; Haze; Submicron particles