Adventurous Manufacturing Follow On: Integrating Living Analytics into Biomanufacturing Processes

Cells possess a variety of mechanisms to sense their environment and adapt to changes by changing the proteins they express. Using synthetic biology methods, it is possible to co-opt these methods to develop analytical tools to report the concentrations of key metabolites of interest for researchers in biomanufacturing. We call these analytical tools whole-cell biosensors. However, developing the whole-cell biosensor is only one part of the challenge. In order to be able to use these in biomanufacturing, we need a way to limit the growth of the whole-cell biosensor and prevent them from having negative interactions with the other cells in the manufacturing process.

In a proof-of-concept grant from Round 1, we showed that encapsulation of the whole-cell biosensor in polymeric spheres made of multiple layers allowed them to retain their biosensing capability and be grown together with mammalian cells making a protein product without negatively affecting the behaviour of the mammalian cells. In this research, we aim to expand on these findings and, together with our industrial partners, demonstrate the potential of this concept in industrial biomanufacturing.

Part 1 of the proposed research will make adjustments to our initial proof-of-concept to make it more compatible with industrial use. This will involve making some changes to the biosensor circuit to make the output easier to interpret and to see changes that occur in a faster time frame. It will also involve making our polymer spheres smaller so that they are more compatible with instruments used to measure fluorescence. Finally, we will show that the biosensor can be used in a bioreactor where it is grown alongside mammalian cells expressing a protein.

Part 2 of the proposed research will develop a concept where the biosensor does not just report the concentration of the analyte, but goes beyond this to adjust the concentration via the expression of enzymes. This will combine two steps in the control of manufacturing processes-sensing and actuation-into the biosensor. To do this, we will modify our original design so that the cells express enzymes that can metabolise the analyte when it is detected. We will also test whether different types of polymer and different shapes (other than spheres) work better in this application. Finally, we will try the system in a bioreactor and test how much metabolite the biosensor can degrade per unit area of the polymer. This will inform the feasibility of using this at larger scales.

Part 3 of the proposed research will build on the work so far to exchange the type of organism used as the host for the biosensor and show that the concept can work for other analytes beyond our initial example. Here we will explore organisms used in food processing as well as natural bacteria that live with and are not harmful for human hosts. The additional analytes that will be explored have been chosen to represent a wide range of chemical structures in order to assess if there are any restrictions on the kind of molecules we can detect.

By the end of the project, we will have developed our initial concept further and facilitated its translation into industry. We have successfully demonstrated a new concept in analytical technology that we think can have a lasting impact on how biomanufacturing processes are analysed and controlled.