In addition, we would like to replace antibiotic resistance marker by another selection method or to knock-in the transgene into the bacterial genome. The extracellular expression of the fibers would reduce the processing steps. Before our solution can be implemented on a large scale, further studies need to be performed on the scaling-up, the capacity of the nucleating fibers under different conditions, the affinity of the modified fibers for calciumcarbonate, the effect of immobilization on the fibers activity et cetera. Some tests we did do proved that our solution would work better when CO₂ is pumped through the water, but further research would be needed. Additionally, in our engineering success pages you can see how we would like to in the future reduce the heat used in our solution by introcuding carbonic anhydrases and pH increasing steps.

Yes we sure can! Two of our favorite collaborative teams UniofBath and iGEM Maastricht are also working on water applications, the sheme down below represents an industrial way in which we would see our solutions working together to build the start of a completely bacterial water purification plant. We proved our solution works with and without salt, so we can be combined easily with the Maastricht technology. Combining with uniofbath allows us to create the optimal water obtained fertilisator collection system! We’ll let Bath and maastricht explain a little more about their projects down below.

“Our system would be most suited to be placed towards the end of the wastewater treatment process. There are also less suspended solids at the end of the process which will reduce the damage to the bacteria and simplify our inputs and outputs.

We aim to recover the bacteria, therefore, a batch process may be more appropriate for our part of the reactor. This allows us to manually place the bacteria into the reactor and remove when required. This could involve placing the bacteria into a tank where the water can flow past, and phosphate can be taken up. The bacteria are encapsulated in a chitosan-sodium alginate matrix as bead form and directly placed into a bioreactor where the water flows in and phosphate can be taken up. The encapsulated bacteria could then be recovered using membrane technology or a centrifuge. To reduce the amount of human involvement we would like to automate this to enable a continuous process where encapsulated bacteria are continuously fed in and removed without disruption to the treatment process.”

“Our product will consist of alginate beads that have cyanobacteria embedded in them. These beads will be in a cube that has a fine mesh sheathing. This cuboid box  will be placed  into a batch of salt water. The water will then flow through the mesh and the polymer matrix until it reaches the bacteria. Once you shine green light on the bacteria, they will start to desalinate water. When the bacteria reach their maximum capacity of salt uptake, the cube will be taken out of the water. Next, the beads will be removed from the cube and a new set of beads will be added. Hence, desalinating the salt water will follow a typical batch process system.

The pore size of the alginate polymer beads will be precisely engineered to facilitate ion diffusion whilst restricting the diffusion of bacteria or other cell components out of the beads. Therefore, we built a three step protection system consisting of the polymer network, the cube and the kill switch to make sure that the bacteria do not end up in the furter processing parts. The bacteria should not be able to escape the beads and the beads should not be able to escape the cube system. If either of the events should take place causing the bacteria to escape the system, the kill switch will prevent them from proliferating.”