Changes and Driving Factors of Bacterial Community Structure of Total Suspended Particle in Aerosols in a Constructed Wetland

Abstract

Bacteria are the principal component of airborne microbes in atmospheric particles, closely related to human health. However, hitherto, the monthly variation in the composition of microbial communities in the constructed wetlands and the relevance to environmental factors is poorly understood. Here, the bacterial composition monthly variation of the total suspended particle (TSP) in a free surface flow reed constructed wetland in a coastal city of Yellow Sea and associated with its influencing factors were investigated. The cultivable bacteria concentration and bacterial community composition were analyzed through the culture-dependent method and high-throughput sequencing. The results showed that the peak concentration of cultivable bacteria in constructed wetland aerosol was found in the reed harvest season (December). The particle size of the bacteria in the TSP was mainly distributed between 0.65 and 1.1 μm, which was smaller than in other environments. A total of 21 phyla and 687 genera were identified. Among them, the first dominant phyla were all Proteobacteria, especially during heavy pollution, the relative abundance was as high as 94.74%, and only Sphingomonas had a relative abundance >1% in all samples. Bacterial genera in the TSP were mainly driven by temperature, while other factors also contributed, such as humidity, NO2, SO2, and PM10 contents.