Benjamin Gallion, “Geographic Distribution Patterns of Arcobacter Cryaerophilus, a Common Microbial Resident of Sewer Conveyance Pipes”
Mentor: Sandra McLellan, Freshwater Sciences, Freshwater Sciences (School of)
Poster #2
Wastewater conveyance systems are colonized by a robust and diverse microbial community. Previous research has focused primarily on microbial communities of wastewater treatment plants, but few have focused on the resident bacteria within conveyance systems. Our lab has shown a high abundance of A. cryaerophilus in wastewater systems. In this work, we examined the phylogenic relationships of these organisms across a broad geographic area and their metabolic potential to cause detrimental effects. One major issue is sulfur cycling throughout the wastewater system which creates harmful byproducts that can cause corrosion, infrastructure failure, and wastewater treatment issues. We tested A. cryaerophilus isolated from sewer conveyance systems in geographically distant cities including Sydney, Honolulu, and Milwaukee (two distinct systems). We screened these isolates using different PCR assays to confirm the genus, then select samples were sequenced for the 16S rRNA gene, and phylogenetic trees were constructed. We also amplified and sequenced the sox genes of isolates of the different sewage systems. We found A. cryaerophilus from Sydney and Honolulu were more similar than those from Milwaukee. We further examined phylogenetic relationships based on temperature and location within a single city. We found the sox genes, which are part of sulfur oxidation pathways, which are often linked to sewer corrosion, were present in these species as core genes. We also examined if the sox genes followed the same phylogenetic patterns across the isolates to confirm the geographic patterns found with analysis of the 16S rRNA gene. This work gives us a better understanding of the wastewater ecosystem and provides more information about the sulfur cycle in these systems which could help us understand how infrastructure failures occur in sewage systems and how these cycles may vary across city and geographical scales.