Who Are Milwaukee Microbes?
Mentor 1
Ryan Newton
Location
Union Wisconsin Room
Start Date
5-4-2019 1:30 PM
End Date
5-4-2019 3:30 PM
Description
The Milwaukee estuary contains a diverse collection of microorganisms, some of which naturally occur in freshwater and others that originate from human activities. In the Milwaukee estuary, both untreated sanitary sewer water (influent) and treated wastewater (effluent) from the municipal wastewater treatment plant discharge large numbers of microorganisms to the ecosystem. The fate of these microorganisms once they mix in the aquatic estuary environment is relatively unknown. Are these wastewater microorganisms viable or do they rapidly decay in this new environment? Similarly, how are estuary microbial communities impacted by urban discharge? To address this question, we collected water samples from influent, effluent, and Lake Michigan. We then created a source-water medium and cross-inoculated each sample onto all source-media. After incubating the culture plates for 12 days at 18oC, we counted the number of colony forming units (CFUs) on each. We found that Lake Michigan plates with influent and effluent inoculate were too numerous to count, along with the cross-plated influent and effluent plates. Effluent plates with Lake Michigan inoculate had the least number of CFU’s, which may be due to lower nutrients in treated sewage. Additionally, we chose single colonies for re-isolation, long term storage, and scaped colonies from plates to collect the full range of microorganisms that were cultured. From the plate scrapes, we extracted DNA, amplified the 16S rRNA genes, and used illumina-sequencing to examine the microbial diversity grown on each plate. We discovered that media-type was preferential for the growth of certain microbial taxa. For instance, Flavobacterium, a dominant genus of influent, grew successfully on each type but best on media derived from influent. Our results indicate that many microorganisms found in untreated and treated wastewater are capable of surviving in the Milwaukee estuary. Further work is needed to understand which organisms contribute to ecosystem processes.
Who Are Milwaukee Microbes?
Union Wisconsin Room
The Milwaukee estuary contains a diverse collection of microorganisms, some of which naturally occur in freshwater and others that originate from human activities. In the Milwaukee estuary, both untreated sanitary sewer water (influent) and treated wastewater (effluent) from the municipal wastewater treatment plant discharge large numbers of microorganisms to the ecosystem. The fate of these microorganisms once they mix in the aquatic estuary environment is relatively unknown. Are these wastewater microorganisms viable or do they rapidly decay in this new environment? Similarly, how are estuary microbial communities impacted by urban discharge? To address this question, we collected water samples from influent, effluent, and Lake Michigan. We then created a source-water medium and cross-inoculated each sample onto all source-media. After incubating the culture plates for 12 days at 18oC, we counted the number of colony forming units (CFUs) on each. We found that Lake Michigan plates with influent and effluent inoculate were too numerous to count, along with the cross-plated influent and effluent plates. Effluent plates with Lake Michigan inoculate had the least number of CFU’s, which may be due to lower nutrients in treated sewage. Additionally, we chose single colonies for re-isolation, long term storage, and scaped colonies from plates to collect the full range of microorganisms that were cultured. From the plate scrapes, we extracted DNA, amplified the 16S rRNA genes, and used illumina-sequencing to examine the microbial diversity grown on each plate. We discovered that media-type was preferential for the growth of certain microbial taxa. For instance, Flavobacterium, a dominant genus of influent, grew successfully on each type but best on media derived from influent. Our results indicate that many microorganisms found in untreated and treated wastewater are capable of surviving in the Milwaukee estuary. Further work is needed to understand which organisms contribute to ecosystem processes.
