For over a century, scientists have been exploring the potential of microbial fuel cells to generate electricity. However, the efficiencies of these small-scale bioreactors have proven to be too low for practical use. Additionally, microbes have revealed themselves to be selective in the substrates they can digest to produce electricity. A team of researchers from the Swiss Federal Institute of Technology Lausanne (EPFL) has made significant progress in this field by engineering Escherichia coli (E. coli), a common species of bacteria, to generate electricity from brewery wastewater. In this article, we will delve into the details of this groundbreaking research and discuss its implications for the future of wastewater treatment.
Unlike exotic microbes that can only produce electricity in the presence of specific chemicals, E. coli has the advantage of being able to grow on a wide range of sources, including wastewater. Taking advantage of this adaptability, the team of researchers modified E. coli’s genome to include protein complexes found in Shewanella oneidensis, a well-known bacterial electricity generator. By incorporating all components of S. oneidensis’ electricity-generating pathway into E. coli, the researchers were able to double its electroactivity compared to previous bioengineered strains. This development opens up possibilities for more efficient and versatile microbial fuel cells.
While experiments in a lab setting have shown promising results, the true test for this technology lies in its performance in industrial settings. In the past, researchers have explored the use of algae in brewery wastewater treatment. It is imperative for breweries to treat wastewater before disposal, as it contains sugars, starches, alcohols, and yeast that can trigger undesirable microbial growth if left untreated. To determine the feasibility of their bioengineered E. coli system, the research team tested it on a sample of wastewater collected from a local brewery in Lausanne, Switzerland. The modified bacteria efficiently consumed the wastewater over a span of 50 hours, outperforming S. oneidensis, which was unable to digest the mixed effluent. This breakthrough demonstrates the potential of using bioengineered E. coli for treating industrial wastewater.
Adaptability and Future Applications
One of the advantages of E. coli’s appetite for various chemical substrates is its potential for adaptation to other waste streams and feedstocks. By further modifying the engineered bacteria, researchers can potentially develop a versatile solution for wastewater treatment in various industries. However, it is crucial to conduct further tests to determine whether the modified E. coli can handle industrial-scale volumes. If successful, this innovation could lead to significant energy savings and a more sustainable approach to organic waste processing.
The research conducted by the team at EPFL marks an important step forward in the quest for efficient microbial fuel cells for wastewater treatment. By harnessing the electricity-generating potential of bioengineered E. coli, the researchers have demonstrated its efficacy in processing brewery wastewater. With further advancements and testing, this technology has the potential to revolutionize the way we treat industrial wastewater and generate electricity simultaneously. By hitting two birds with one stone, we can contribute to a cleaner and more sustainable future.