Multifluid Input:

Because our team was lucky enough to meet with researchers and industry workers in the water testing and biosensor fields, we were able to learn and adapt our project to more applicable needs. Our meeting with Bioengineers was on August 16, about 12 weeks into our project. One of the biggest changes we made from our meeting was the incorporation of a multifluid input design. Figure 1 shows the original product design - a design that didn’t take into account the sensitivity of biosensors to various liquid parameters. After our meeting with researchers, we knew we had to make our system more compatible and applicable for those working with a wide variety of biosensors. The difficult part was that most of our project design was completed at this point. But knowing we could make our project more universal, we decided to add sensors and liquid reservoirs to sense and regulate key components like pH and salinity. We also made our system flexible in that the content of the liquid reservoirs as well as the sensors being used, could be swapped out depending on the parameters the user wants to regulate. This new design provides a standardized system for biosensor testing, one that isn’t limited to a few liquid variables. This helped us in reaching the true purpose of our project - to make a system meaningful and compatible with labs from all around the world. Below the figures are our meeting questions and notes from our meeting with bioengineers. We learned a lot from this meeting and documented it all for future use.


Figure 1: Original Concept with 2 tank system

Figure 2: Updated 5 Tank system to incorporate multi fluid input design



Wastewater Treatment Facilities:

One of the main flaws that Deep Island mentioned was the buildup of biofilm in their machinery that requires extensive cleaning, further adding to the turnaround time for results. From learning about these issues, we improved our project by adding a three-stage filter process that would remove the need for daily maintenance/cleaning. It was this along with the reduced cost and results turnaround time of our system that makes it directly applicable for Deer Island Testing facilities. Another big improvement we made from our meeting was meeting the compatibility needs for copper biosensors for the successful testing for Copper. From talking to the Deer Island representative, we learned about their inability to test for metal elements like Copper for onsite testing facilities. We did further research and found the pH values required for current industry biosensors (genetically modified yeast cell- based copper detection biosensors). From this found pH of 8.1, we calibrated our system for the variation of pH from a base solution with pH of 7. In the figure below, you can find results from this calibration. To insure successful application, we did multiple runs of getting our base solution of pH 7 to the optimal value of 8.1 This makes our system directly deployable to Deer Islands onsite testing fields and makes their testing capabilities expand. The rest of our meeting notes and questions are also documented below. They were vital to the improvement of our project in various ways.


Figure 3: Time vs pH for successful runs of 7 to 8.1 pH

Engineering Biosensor Compatibility:

We also wanted to connect Deer islands needs to the work conducted by other iGEM teams in past competitions. After looking through the registry, we discovered that a potential solution to aiding in the Copper sensing compatibility issues lied right in the heart of the competition. We found that the promoter BBa_I760005 in the registry would be the perfect in aiding in Deer Island's issues. After some conversations with our Bioengineer colaborators, from this part, it would be possible to pair this promoter with another fluorescent protein in order to engineer the perfect biological system. Very simply, in the presence of Copper, the Copper would bind to the promoter and allow transcription of the fluorescent protein, thus producing a fluorescent output. This output could be read as a signal which can then be further processed to determine the presence of Copper in a given aqautic environment, or in this case, one of the many testing sites located at Deer Island. As seen by its description in the registry, the level of Copper is able to influence the strength of the fluorescence, proven via flow cytometry. This could work perfectly as a solution to Deer Island's need to test for Copper by telling them both the presence and level of Copper in a sample.


Figure 4: Concentration of Copper vs RFP Flourescence Performance

References:

Vopalenska, Irene. “New Biosensor for Detection of Copper Ions in Water Based on Immobilized Genetically Modified Yeast Cells.” Biosensors and Bioelectronics, 15 Oct. 2015.

Zakharov, Gennady. “IGEM Registry of Standard Biological Parts.” IGEM, 20 Aug. 2007.