Bacteria—what a love-hate relationship the world shares with it. Scientists know them as single-celled organisms capable of thriving in different environments. Most people know them as little buggers capable of causing illnesses that lead to hospitalization or even death. But there’s more to bacteria than meets the eye.
Sewage water, a type of wastewater produced by a community of people and containing all sorts of excrement, often contains bacteria and viruses which can contaminate the environment and people that live in the area. So, who would think that mixing both bacteria and sewage would be a good idea?
Despite bacteria’s potential for harm harmful, combining certain types of bacteria with sewage water could produce positive results. And no, this has nothing to do with the Teenage Mutant Ninja Turtles.
In a recent study, researchers showed that purple phototrophic bacteria, which store energy from light, can recover most carbon from organic matter while generating hydrogen energy. Hydrogen energy is the latest and most promising endeavor in terms of renewable energy. Similar to electricity as a clean energy carrier, hydrogen energy could reduce society’s reliance on oil for fuel, which in turn could reduce the release of greenhouse gases, and other pollutants.
In this instance, the purple organism, which belongs to the biggest group of bacteria, uses infrared light to fuel its metabolism, according to Dr. Daniel Puyol, a scientist at King Juan Carlos University in Spain. “They can perform a range of metabolic reactions, making them a kind of metabolic Swiss army knife,” Puyol said. “For this reason, these organisms are ubiquitous in nature.”
Similar to plants, the purple bacteria are able to provide carbon, electrons, and nitrogen required for photosynthesis. However, they do not rely on CO2or H2O—instead, they use organic molecules and nitrogen gas for photosynthesis inputs. This allows the phototrophic bacteria to produce hydrogen gas and proteins, all while growing faster than alternative bacteria because of their metabolism.
The organisms prefer bodies of water, which is where sewage water comes into play. Wastewater treatment plants’ main problem is the carbon footprint they leave behind. A light-based process that Puyol and his team produced could provide a means to harvest energy from sewage while leaving no carbon footprint.
In their study, the group of researchers realized that the nutrient blend that fed the highest rate of hydrogen production also reduced the amount of CO2produced. In a separate test involving the electrons from a cathode, the purple bacteria used the negatively charged particles to capture more carbon from organic compounds by photosynthesis. The process proved that the purple bacteria release fewer toxins into the atmosphere, and that it could be the energy source of the future that scientists are looking for.
In a world where nonrenewable energy resources are dwindling, the race to find a suitable replacement is on. Renewable sources such as wind and nuclear energy already exist, but none of them have shown signs of being a reliable energy source.
Purple bacteria might be the way to go as the team received a grant to continue research on their methods. John Dallagnese, a freshman studying Mechanical Engineering at NJIT, feels that more people need to accept the idea of renewable energy: “This is another step into our new renewable future. The science and technology is there…we just need everyone to get on board with it.”