Garrett Scapellato, “Weather-Weary Wastewater Bacteria”
Mentors: Ryan Newton and Emily Lamartina, Freshwater Sciences

To relieve pressure caused by heavy rain, wastewater treatment plants release raw or partially treated sewage into natural waterways. These events, called combined sewer overflow (CSOs), introduce waste-associated bacteria into natural ecosystems and carry great risks to environmental and public health. Flavobacteriales, one of the most prevalent bacterial groups in aquatic habitats, including wastewater, are linked to deadly fish diseases that affect both wild and farmed fish populations. Focusing on relevant and easily cultivated Flavobacteriales could provide insight into the impacts wastewater microbial communities have on natural ecosystems, particularly during CSOs. Notable Flavobacteriales groups are Flavobacterium and Cloacibacterium. Through DNA sequence analysis, these genera showed diverging responses to cold and warm wastewater temperatures. However, these findings have not yet been observed in vitro. In this project, we will use a targeted PCR approach to screen Flavobacterium and Cloacibacterium from an archive of cultures isolated from Milwaukee wastewater. Once identified, cultures will be subjected to changes in temperature, and responses will be assessed by calculating growth rates. We predict that Flavobacterium will grow more rapidly than Cloacibacterium in cold temperatures associated with winter and spring in Milwaukee (10°C), and Cloacibacterium will thrive in the warmer temperatures of summer and fall (18°C). Our work demonstrates the utility of using Flavobacteriales as model organisms for wastewater research and can aid the monitoring of ecosystem health following CSOs, provide a precedent for future research with wastewater organisms, and aid the understanding of changing fish populations in conjunction with changes in weather.