Dynamics of airborne bacterial community during biofiltration of gases from a swine house

Abstract

Biofiltration is one of the important methods treating gases from swine houses. However, the dynamics of airborne bacterial community during biofiltration are unclear, which restricts the wide application of biofilters. In this research, the pine wood chips (W) and the mixture (pine wood chips + swine manure compost, WC) were selected as biofilter media, respectively, and the biofilters were operated to treat air exhausted from a nursing pig house. 16S rRNA gene sequencing was applied to analyze the airborne bacterial community before and after biofiltration. Results indicated that α-diversity of airborne bacteria had no significant change during biofiltration (P>0.05), and β-diversity analysis demonstrated that the bacterial community in gases after biofiltration was significantly different from that before biofiltration according to statistical analysis (P<0.001), while they were quite similar and more than 96% OTUs of them were the same. Therefore, it could be speculated that the airborne bacterial structure after biofiltration mainly depend on the inlet airborne bacterial community. In addition, the variations of airborne bacterial relative abundance and functions related to human diseases during biofiltration in two treatments were not all the same, which might imply that the dynamics of airborne bacterial structure during biofiltration were also affected by biofilter media. These results could help us to be aware of the variation of airborne bacterial community during biofiltration and the relevant influence factors, which may promote the improvement of biofiltration for gases from pig houses and reduce the pollution of bioaerosols.