Effect of temperature on the substrate utilization profiles of microbial communities in different sewer sediments.

Sewer systems represent an essential component of modern society. They have a major impact on our quality of life by preventing serious illnesses caused by waterborne diseases, by protecting the environment, and by enabling economic and social development through reducing flood risk. In the UK, systems are normally large and complex and, because of the long lifespan of these assets, their performance and hence their management are influenced by long-term environmental and urban changes. Recent work has focussed on the long-term changes in the hydraulic performance of these systems in response to climate change, e.g. rainfall and economic development. One climate-related driver that has received little attention is temperature, which may in itself have a complex dependence on factors such as rainfall. This study uses Biolog EcoPlates to investigate the effect of different temperatures (4 degrees C, 24 degrees C and 30 degrees C) on the carbon substrate utilization profiles of bacterial communities within sewer sediment deposits. Distinct differences in the metabolic profiles across the different temperatures were observed. Increasing temperature resulted in a shift in biological activity with an increase in the number of different carbon sources that can be utilized. Certain carboxylic and amino acids, however, did not support growth, regardless of temperature. Distinct differences in carbon utilization profiles were also found within sewers that have similar inputs. Therefore, this study has demonstrated that the carbon utilization profile for microbial communities found within sewer sediment deposits is dependent on both temperature and spatial variations.