PRJDB2415 Effects of Non-Methane Volatile Organic Compounds on Performance and Microbial Community of Methanotrophic Biofilter Methane and non-methane volatile organic compounds (NMVOCs) are simultaneously produced from landfill. Four lab-scale biofilters (BF) packed with pumice and granular activated carbon (10:1, w/w) were operated with 10,000-60,000 ppm CH4 and 10-200 ppm NMVOCs such as dimethyl sulfide (DMS), benzene (B) and toluene (T) at a space velocity of 3 h-1. Ribosomal tag pyrosequencing and quantitative PCR were performed for bacterial community analysis. Methane elimination capacities proportionally increased with methane loads in all BFs. Methane could be removed up to 82.8%, while DMS, B and T were completely removed. Compared to BF 1 without the NMVOCs, DMS alone significantly enhanced the methane removal performance (BF 2), whereas B/T alone had no effect on it (BF 3). However, DMS and B/T together significantly reduced the performance (BF 4). A canonical correspondence analysis result showed that DMS and B/T strongly influenced relative abundances of the microbial composition. DMS significantly diversified and modified the bacterial and methanotrophic communities, but its effect was nullified by coexistence of B/T as same with the performance result. The existence of DMS and B/F favored the growth of Methylosarcina and Methylomonas, respectively, resulting in the substantial change of methanotrophic community. However, methanotrophic population densities on a packing material basis did not significantly differ among the BFs 1-4. It was apparent that the variation of methanotrophic performances resulted from the community change by the NMVOCs. Our results proved that the co-emitted NMVOCs along with methane are an important abiotic factor to influence performance and microbial community of methanotrophic biofilter, and also suggest that interaction effects among NMVOCs are unpredictable. Methanotrophic biofilter study