Fatty acid methyl ester analysis of microbial communities in biofilters inoculated with different sources

grantor: University of TorontoBiofiltration is an air pollution control technology which relies on the activity of a microbial community attached to the biofilter media for contaminant mineralization. The effect of the microbial inoculum source on the biofilter performance and the characterization of the microbial community using fatty acid methyl ester (FAME) analysis was experimentally studied. The experimental design included three parallel biofilters, each inoculated with a different source of microorganisms and run under equivalent conditions with air contaminated with $\alpha$-pinene, a hydrophobic volatile organic compound, (loading rates of 5 to 30 g $\alpha$-pinene/m$\sp3$ bed medium/h). Two experimental runs were performed and each run led to the same conclusions. Although the inocula had a significant effect on the acclimation time of the biofilter, the inocula did not have a great effect on the long term biofilter performance. The long term steady state removal rate was approximately 10 g $\alpha$-pinene/m$\sp3$ bed medium/h. Fatty acid methyl ester (FAME) analysis compares differences in microbial communities based on the type and distribution of fatty acids. Fatty acid profiles indicate that the inocula in each run were significantly different. However, background fatty acids from the wood based biofilter media caused interference and when the inocula were mixed with the media, the fatty acid patterns became similar. During the operation of the biofilters, when the $\alpha$-pinene degradation activity of the three biofilters were similar, differences in the fatty acid profiles of the three different biofilters were not detected. FAME analysis on a larger bench scale biofilter with the same media but a higher microbial biomass indicated differences in the fatty acid profiles which corresponded to differences in the $\alpha$-pinene degradation rate.M.A.Sc