Using a biological wastewater treatment plant as a model ecosystem, scientists have found the importance of bacteria in the purification process of wastewater. Wastewater is a pool of nutrients for bacteria, such as energy-rich substrates like fats and carbohydrates. However, different bacteria have different ideal environments. For example, a certain bacteria may adapt better in waters that contain more fat substrates. By combining genomics, transcriptomics, proteomics, and metabolomics to new bioinformatic technologies, scientists can create treatment plants with different substrate compositions, and analyze bacteria that efficiently consumes the nutrients.