Document Type

Student Research Paper


Spring 2016

Academic Department


Faculty Advisor(s)

Dr. Debra Wohl


The interplay between humans and built environments is a new frontier for microbial ecology. Approximately 90% of human activities occur indoors, and current estimates for microorganism diversity in buildings are in the trillions. Previous studies have investigated microbial resuspension (i.e., the surface to air release of biotic and abiotic particulate matter) via temporal analysis of human occupancy patterns and spatial analysis of different flooring materials. However, prior research has not sufficiently addressed flooring structure, human-mediated resuspension in unconstrained environments, and phylogenetic analysis within the context of a single study. Our investigation examined the effect of surface composition and human traffic intensity on the taxonomic composition of airborne microbial communities. In a college academic building, 24 air samples were collected over carpeting during high (n=6) and low (n=6) human activity periods and over linoleum during high (n=6) and low (n=6) activity. DNA was extracted, amplified using prokaryotic 16S primers, sequenced using the Illumina MiSeq platform, and analyzed with the Quantitative Insights into Microbial Ecology statistical package. Prior to merging reads and quality filtering, 227 sequences were yielded across 14 samples and one control. Alpha (within sample) diversity indices of genera richness and evenness were reported along with beta diversity (between sample) comparisons of sequence counts and shared genera across sampling conditions. While low sequence yields precluded the determination of the explanatory power for the activity and flooring variables, the present study’s limitations and new directions for investigating the composition of indoor microbial communities were discussed. With methodological revisions, we anticipate that future studies will help to elucidate the role of building design in modulating microbial resuspension dynamics induced by human traffic patterns between indoor and outdoor environments.

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