3D printed “living material” purifies contaminated water

Researchers at the University of California at San Diego have developed a novel material that can clean water of pollutants. The so-called “living material” is a combination of biological and synthetic components. Using 3D printing, they created a structured matrix based on algal polymer infused with genetically modified bacteria.

The embedded bacteria were modified to produce an enzyme that converts organic pollutants into harmless molecules. In addition, the bacteria were programmed to be self-destructive in the presence of a specific chemical. This allows for their targeted elimination once purification is complete.

According to lead researcher Jon Pokorski, the combination of polymer material and biological system allows for a “living material” that can respond to environmental stimuli – a property that conventional plastics lack. In a proof-of-concept, the team showed that their material is capable of removing the textile dye pollutant indigo carmine from water.

The genetically modified bacteria were engineered to react to theophylline, a molecule found in tea and chocolate. Theophylline triggers the production of a specific protein that kills the bacteria. According to the researchers, this represents a way to specifically eliminate the bacteria after they have been cleaned.

The “living material” demonstrates a novel approach that combines methods from biology and materials science. 3D printed fabrication allows the bacteria to be positioned in a structured matrix that optimizes their survival and activity.

The researchers see great potential in the approach for sustainable water purification. In the future, the system will be improved to allow the bacteria to self-destruct without the addition of external chemicals.

More on this topic can be found in the scientific paper “Phenotypically complex living materials containing engineered cyanobacteria,” published in Nature Communications.