Improvement for the protein system
1. For example, it is possible to get proteins that have higher affinity with plastics by phage display. Our device can stick to plastic more stronger with such protein. The amount of the proteins might be fewer than we calculated.
2. This time we used various proteins that bind to polyethylene terephthalate (PET), polypropylene (PP) or polyurethane (PU). Also, several proteins that bind to other kinds of plastics are known. If our device displays various plastic-binding proteins, it might be able to collect several kinds of synthetic fibers at the same time.
3. We can improve the stability of our device in several ways. We can just add protease inhibitor at the same time, or some mutation might make protein capsules more durable.
Improvement for the hardware
1. As mentioned in the hardware page, we think there must be an advanced way to introduce our proteins into laundry wastewater. Our device is designed to passively supply our proteins, so it is not regulatable as we want. It would be more effective if we could build an electronic device which has a sensor to detect the flow of wastewater and releases our protein solution at a fixed rate and amount.
2. There is a compact build-in filtration system that has already been on sale from PlanetCare [1]. It can be installed on the drain hose and collect the fibers released from washing machines. We believe if we could use it together with our aggregation system, it would be more effective and the rate of those uncaptured would be decreased to such a small amount.
Brand-new approaches
There are also more advanced and practical ways of application that came to our minds as follows.
1. Detecting microplastics is still a hard work even today. This time we successfully marked microfibers with GFP, so we may also be able to detect microplastics in the natural environment by marking them, and possibly count them with microscopy. Furthermore, if we could selectively mark them with different fluorescent proteins by using different binding proteins, it enables us to identify which microplastic fragment is made of which polymer.
2. Encapsulins can display up to 60 proteins on their surface. So we would be able to replace some of plastic-binding proteins for proteins which bind to other things that are abundant in wastewater, such as cellulose or microorganisms, and aggregate microfibers with them as well. This way might lead us to find more and more efficient target with which to aggregate micorfibers.
3. A research group at Chalmers University of Technology has developed an efficient process for breaking down any plastic waste and then transform it back into new plastic of the same quality as the original [2]. In another aproach, metabolizing plastics into useful compounds are seen. In both cases, collecting and concentrating plastics might promote those processing.
References
1 PlanetCare.
https://www.planetcare.org/en/ 2 Chalmers University of Technology (18 Oct 2019).
All plastic waste could be recycled into new plastic.
https://www.planetcare.org/en/ 2 Chalmers University of Technology (18 Oct 2019).
All plastic waste could be recycled into new plastic.
