We believe to have proven that our engineered cells could potentially represent a powerful and cost-effective solution to combat quagga mussel invasion. However, to go from the laboratory to real-world application, we carefully thought of the proper ways with which we could actually use our cells. This would require overcoming certain challenges that remain for a possible marketing and commissioning of our products. Thus, this step must not only take into account all the modifications previously made but adapt the design so that it can be used on a large scale.
For Zosteric acid, this chemical is easily and passively accumulated in the supernatant of the cell cultures, making it easy to separate the chemical from the cells. Therefore, zosteric acid, separated from the cells, can be used as a non-GMO product and simply added in high enough concentrations to the pipes.
Also, regarding the application of FitD Toxin, we would use it for the purpose of treating clogged drains, as the zosteric acid would prevent them from attaching to the strainer and entering the drain. As the "La Maison de la Rivière" foundation told us, they have installed two types of pipe systems, one for the infrastructures that require drinking water and another for all the infrastructures that do not need drinking water, such as toilets and heating. Initially, we aim to only treat the network of non-potable pipes with our FitD toxin. This would be a temporary cleanup, done only if necessary.
In case the implementation of a liquid solution proves to be infeasible due to the potential instability of FitD toxin in a solution, we would go in the direction of a powder, which is the form of the currently available product Zequanox (information provided by the Water Department of Lausanne). Well established protocols exist to turn bacteria extracts into powder through lyophilization, a process during which water is removed while the sample is frozen inside a vacuum. This procedure allows to stock biological material more densely compared to standard aqueous solutions, while retaining protein stability and activity. Lyophilization of our product would significantly decrease storage expenses and ensure long shelf-life of our toxin (even at room temperature).
Furthermore, in order to create some kind of coating to ensure the immobilization and/or the slow release of the zosteric acid, we propose to incorporate the molecule in one active film. One feasible option would be a layer of silicone, a setup that has already been tested for preventing freshwater bacterial attachment (Barrios et, 2005). This study demonstrated that when zosteric acid was uniformly dispersed in silicon forming tiny aggregates (4 micron or less) the release rate was generally between 0.03 and 0.2 μg/day-cm2, and was maintained for up to 6 months. The extremely slow release suggests that the service life of our coatings could be very long-lasting even with a small amount of zosteric acid incorporated.
Going further, a combination product is worth considering in the future. This way, we comprehensively address the Quagga mussel invasion both curatively by applying FitD toxin to exterminate the existing Quagga mussels attachment and preventively by applying zosteric acid. The latter would kill mussels and prevent new ones from settling at the same time, but would require further experimentation and research to make it a final product.
In order to be able to sell our products in the future, we must be completely transparent about the composition of our products and the design by which they have been created in order to comply with current legislation. Therefore, our product must be accessible, easy to use, effective for our target market and avoid any risk to other freshwater organisms.